top of page

Top 5 Biggest Glass Cannons in MMA

In honour of Alistair Overeem's upcoming fight on Saturday, I rank the top 5 glass cannons in MMA history

For the uninitiated, a glass cannon in combat sports is a fighter who has superb offensive capabilities that often result in big knockouts (the "cannon"), but also has defensive deficiencies and typically a chin that doesn't hold up well under fire, resulting in knockout losses (the "glass"). As such, glass cannons make for exciting fights and typically deliver vicious knockouts, whether they're starching their opponents or getting clocked themselves.

Glass cannons usually come in the form of heavyweights, as knockout power is common there and thus the ability to absorb a big shot is more important and significantly more noticeable if you can't.

This list is looking at fighters who have spent the majority of their careers fitting the criteria for a glass cannon; knockout artists who simply aged and lost their chins are common and typically they lose much of their "cannon" characteristics as well as they get older. Those fighters are thus not included in this list, as they only became glass cannons when they were past their prime (for some examples: Fedor Emilianenko, Chuck Liddell, Shogun Rua).

Without further ado, let's take a look at the biggest glass cannons in MMA history.

5. Todd Duffee 9-3 1NC (9 knockout wins, 3 knockout losses)

Todd Duffee is a hulking mass of muscle and aggression. When he burst into the UFC back in 2009, Duffee was viewed as the future of the heavyweight division. A physical specimen (who also "needed" testosterone replacement therapy back when it was legal) with explosive athletic ability, great takedown defense, heavy hands and relentless offense, his potential was massive.

Duffee started his career with 6 straight knockout wins, including a UFC record (at the time) 7 second KO over the late Tim Hague in his UFC debut. Duffee quickly became one of the hottest prospects in the heavyweight division - that is, until he met pudgy wrestler Mike Russow at UFC 114.

The fight's first two rounds showcased Duffee's surprisingly solid boxing ability for a heavyweight at the time, his superb takedown defense and raw strength against a good collegiate wrestler, and his crushing power. Russow was essentially used as a punching bag by the young prospect, getting battered at every turn and offering virtually nothing in return. But with such an offensive onslaught that somehow hadn't resulted in a finish, Duffee's imposing frame was running low on gas. In the third round, Russow started landing his pitter-patter punches which looked like a mere annoyance to his vastly overpowered foe.

Until a weak-looking right hand from Russow landed flush and sent Duffee crashing to the canvas.

An insultingly light hammer fist just made the finish all the more comical, and in the blink of an eye, the division's brightest prospect was turned into the butt of a joke. Obviously cardio played a major factor, but the fact that such a weak punch from a fighter not known for having any power at all managed to knock him unconscious, Duffee's chin was brought into question and for good reason.

Oddly, the UFC released Duffee after a single loss, stating that the young heavyweight needed an "attitude adjustment". Duffee went on to face Alistair Overeem on short notice for a New Year's Eve show in Japan, at the height of Overeem's powers. Duffee got lamped in just 19 seconds.

After an extended layoff due to injuries (which had already become a staple of Duffee's career, and would continue to do so in the years following), Duffee rebounded with a 34-second knockout win that earned himself a return to the UFC which was starving for exciting heavyweights.

Two quick knockout wins over low-tier fighters earned Duffee a spot against former UFC champion and submission specialist Frank Mir. Mir had recently been on a 4-fight skid before righting the ship with a highlight reel knockout of Bigfoot Silva. Mir was expected to go for the takedown early and if he couldn't secure it, his suspect chin and porous defense was expected to cause him major problems against someone with the offensive capabilities of Duffee.

The fight started with the two heavyweights slugging it out in the middle of the octagon, winging shots and narrowly avoiding certain doom. Mir landed several good shots before a return from Duffee sent him onto his back foot - Duffee then charged forward, winging one of the ugliest and least technical right hooks you could ever imagine. That poor choice sealed Duffee's fate, as Mir smoothly moved his head offline and rifled a straight left hand down the middle that cracked Duffee's chin and shut his lights off in an instant.

Duffee cemented his status as a top-tier glass cannon that night - a slugger that can put anyone out on a moment's notice, but can also be knocked out in spectacular fashion at any time. Win or lose, all 12 of his fights ended via a vicious knockout, making him an exciting addition to any card in need of action.

After an injury layoff that lasted over 4 years, Duffee returned to action earlier this year in Vancouver. Looking noticeably less muscular than his prior form (thanks USADA), Duffee took on a durable mid-tier heavyweight and looked sharp early, rocking his opponent on multiple occasions and nearly earning himself a finish. He even had a bit of strategy this time, as he looked to clinch up and avoid returns after his trademark barrages of punches, though he still ate some shots anyway. The heavyweight firefight ended in disappointment however after Duffee was inadvertantly poked in the eye and started seeing double, leading to a No Contest as he was deemed unable to continue.

Even with the anticlimactic ending, the fight was one of the highlights of the event and was a good old fashioned slobberknocker. Duffee may not be a technical striker or a defensive savant, but he always delivers excitement and enthusiastically fulfills his role as a true glass cannon.

Here's hoping he can stay healthy outside the cage and inject some consistency into his career.

4. Jimi Manuwa

17-6 (15 knockout wins, 5 knockout losses)

One shot, one kill. That's the philosophy Jimi Manuwa fights by, for better or for worse.

A 6'1 light heavyweight with a long frame and massive power, Manuwa combines great offensive boxing with nasty knees and whipping kicks. His offense is amongst the best in the division and his left hook in particular is capable of separating anyone from their consciousness at any time.

The UK's "Posterboy" became one of the most feared fighters in the 205-pound division when he made his way into the UFC back in 2012, demolishing the mid-tier but incredibly tough Kyle Kingsbury in his debut to raise his record to a sublime 12-0 with a 100% finishing rate (11 by way of knockout).

His vicious power, strong clinch work, and solid boxing led him to another two finish victories (both injuries inflicted on his opponents) including a top-10 win over the late Ryan Jimmo before he would face a top contender in Alexander Gustafsson. Gustafsson had cut through the division and was coming off of 2013's Fight of the Year opposite Jon Jones, in a title fight that Gustafsson arguably won, making him the top 205er on the planet in the eyes of many.

Despite being a striker, Gustafsson looked scared to hang out on the feet with the power that Manuwa brought to the match. Instead, the Swede took his opponent down early and kept on him for the entire round, much to the chagrin of the fans in attendance. After instilling the fear of the takedown into Manuwa in the opening stanza, Gustafsson mixed in his boxing to land uppercuts on the Englishman as he backed into the cage and was looking to stuff a takedown that simply wasn't coming. A nasty knee followed by more uppercuts sent Manuwa to the canvas and a few hammer fists ended Manuwa's night early in the second round.

Manuwa didn't find MMA until later in his life, with his first professional fight coming when he was already 28 years old. As fight fans know, most fighters (though there are exceptions) start losing their ability to take a shot in their mid- to late-thirties. Unfortunately for Manuwa, by the time he had reached the upper echelon of the sport, he was already in his mid-thirties and his chin was less than stellar.

After a gritty bounceback fight which earned Manuwa the first (and only) decision win of his career against Jan Blachowicz, Manuwa was slotted against one of the fiercest knockout artists in MMA: Anthony "Rumble" Johnson.

Fans were excited for the matchup: two of the hardest hitting strikers in the UFC slugging it out for a coveted contendership slot. Unfortunately, Rumble borrowed from Gustafsson's playbook, not even pretending to want to strike with the British banger before diving on a takedown. Rumble simply laid on Manuwa, using his mass to keep Manuwa pinned and looking to tire out Jimi by making him carry his weight. Early in the second, Johnson came out firing with a right hand that caught Manuwa clean and that was all she wrote.

Fortunately the cannon would return to the fore in his next two fights. After stuffing Ovince St. Preux's wrestling and picking him apart at range, a tired OSP was no match for Manuwa's bone crunching power and hit the canvas in supremely violent fashion after Manuwa backed him into the cage and went for the kill. A slick left to the body primed a brutal right hand which dropped OSP, who returned to his feet only to get planted by Manuwa's brilliant left hook.

The next victim of Manuwa's left hook (my favourite strike) was Corey Anderson, who is now one of the top light heavyweight contenders in the world. In their 2017 matchup, Anderson looked like a deer in headlights when the collegiate wrestler was unable to get Manuwa to the mat after several takedown attempts. The Posterboy always had solid takedown defense to complement his boxing focus, but after it was shown to be not quite up to par against top contenders in Gustafsson and Johnson, he had clearly worked hard to ensure that would no longer be an issue. The difference in striking was made clear, and Anderson recoiled every time Manuwa landed even a glancing blow.

Just past the midway point in the opening frame, as Anderson was backing away, Manuwa launched a long left hook that sent Anderson toppling over like a falling tree. No follow-up shots were needed and Manuwa found himself back into a top contendership position.

Jimi was placed against the streaking Volkan Oezdemir, who was coming off an odd 28-second KO over a top 10 opponent himself. Manuwa would be on the receiving end of another of Oezdemir's odd knockouts - after getting into the clinch, Oezdemir rifled off hooks and uppercuts that rocked Manuwa despite Oezdemir's back being against the cage and his feet in poor position to generate power. Manuwa was stumbling backward and flailing to try to recover while continuing to eat shots before being thrown onto the mat and put out cold with a few ground strikes in a mere 42 seconds.

A rematch against Jan Blachowicz delivered an exciting war as both men rocked each other and landed throughout, with Manuwa wobbled virtually every time Blachowicz hit him but he was somehow able to survive the full 15 minutes and land shots of his own. There, Jan's superior defense and grappling nabbed him the win, and Manuwa was handed his first (and only) decision loss.

Against surging Brazilian murderer Thiago Santos, Manuwa engaged in an insane back and forth brawl. Where many would have adjusted their style to try and avoid getting knocked out again by this point, Manuwa doubled down on his exciting style and was willing to sacrifice his brain cells to put on a show for the fans. Santos and Manuwa put on the Round of the Year with their insane war at UFC 231. In between the rounds of the hectic firefight, the younger Santos was able to recover much better than his older peer, and was able to close the show early in the second round (ironically by a left hook, Manuwa's favourite).

The Posterboy would return to the Octagon one last time earlier this year to face a prospect in Aleksandar Rakic; he was caught by a head kick and brutally knocked out in just 42 seconds.

Jimi Manuwa's career didn't enjoy great longevity and he never quite reached the ever-elusive title shot he had gotten so close to, but he epitomized what makes a glass cannon so great - he had raw, unsettling power along with brilliant offensive tools, and even though he also suffered some vicious losses, he never changed the exciting style that the fans loved him for. He lived by the sword and died by the sword without a second thought, and I'll be damned if he didn't give MMA fans some great memories along the way.

3. Andrei Arlovski 28-19 (17 knockout wins, 11 knockout losses)

Andrei Arlovski is the prototypical glass cannon in MMA.

Starting his career way back in 1999, the Belarussian heavyweight is one of the pioneers of the sport and is incredibly still competing some two decades later. His vaunted right hand is the stuff of legends, but his chin has famously let him down time and time again throughout his lengthy career.

Fittingly, Arlovski's very first professional MMA fight ended in a brutal knockout loss for the debuting 20 year old. Three straight finishes in under 90 seconds (two knockouts) earned him a call up to the UFC, where he would lock up a 55-second armbar for his promotional debut way back in the year 2000. From there, he would face two early UFC legends in Ricco Rodriguez and Pedro Rizzo, being knocked out by both in the third round of each fight.

From there Arlovski would put together a title run, winning three straight by knockout including a vicious KO over Vladimir Matyushenko and a mauling of the famously durable punching bag Wesley "Cabbage" Correira. After UFC heavyweight champion Frank Mir was severely injured in a motorcycle accident, the UFC held an interim title bout between Tim Sylvia, who had recently had his arm broken from an armbar by Mir, and top contender Andrei Arlovski.

Arlovski dropped Sylvia with a thunderous right hand before going for an achilles lock and tapping out the giant 6'8 favourite in just 47 seconds. Putting all of his skills together in the Octagon, it looked like Arlovski had the entire package as a heavyweight: superb athleticism, raw knockout power and solid boxing, good takedown defense and a submission game to boot.

He went on to defend his interim title with a first round knockout before the UFC promoted him to undisputed heavyweight champion due to Mir's extended injury absence. He would defend that title as well with a wicked 15-second KO of Paul Buentello, landing a short right cross counter that caused the challenger to fall directly onto Arlovski's back.

It looked to fans as though Arlovski would have a long reign as UFC champion when a rematch with Tim Sylvia came to fruition. Unfortunately for Arlovski, his chin would be cracked once again as Sylvia landed a short counter when Arlovski came forward with his trademark right hand, dropping him to all fours before follow-up shots left poor Andrei facedown on the canvas.

A rubber match was made to determine once and for all the better fighter at UFC 61, only for both fighters to stink up the joint with an incredibly tepid affair with both fighters looking wary of each other's finishing ability and thus largely refused to engage at all for a full 25 minutes. Sylvia would defend his title with a decision win simply by being slightly less terrible than Arlovski was that night.

Andrei would bounce back by rattling off three more victories, two by knockout, before his UFC contract expired and he went on to sign a lucrative contract with the newly formed Affliction MMA promotion. There, he flatlined the extremely durable Ben Rothwell with another of his trademark right hand bombs followed by an uppercut.

Being leased out to EliteXC (which also co-promoted with Affliction), Arlovski's ridiculously powerful right hand would solidify its legacy as one of the most powerful weapons in MMA history. The iron chin of "Big Country" Roy Nelson was no match for a prime Arlovski's piston straight right, as an uppercut wobbled the famously durable Nelson before his trademark straight right closed the show.

If you don't know, Roy Nelson was one of the most durable fighters in MMA history and arguably had the most ridiculous ability to absorb punishment we have ever seen in the sport. Nelson wouldn't be stopped again for some six years after fighting the top heavyweights on the planet in 14 fights after the Arlovski loss; the likes of a prime Junior Dos Santos, Fabricio Werdum, Stipe Miocic, Daniel Cormier, and more all put absolute beatings on Nelson yet failed to finish the iron-jawed American. He simply ate heavyweight power punches for breakfast, and that isn't even a dig at his weight. The fact that Arlovski was able to knock him dead shows just how lethal Arlovski was back in the day.

Of course, his next fight showcased the other side of the Arlovski coin: the glass.

Facing the legendary Fedor Emilianenko back in Affliction, many viewed their matchup as a test to determine the true best heavyweight in MMA at the time: former UFC champ Arlovski who was riding high on a killing spree, and the last PRIDE champion Fedor who was on a 24-fight unbeaten streak and whose only loss had come via a controversial cut stoppage.

Arlovski surprised many by coming out and taking it to Fedor, rifling off combinations and hurting the seemingly unstoppable Russian pioneer. A single poor decision later, Arlovski was napping on the canvas.

Arlovski had backed Fedor into the corner (Affliction events took place in a boxing ring despite having MMA rules, similar to PRIDE) after he landed a right hand and a push kick. He then decided to try a flying knee against his hurt prey. Were it successful, he would have become the first man to legitimately beat "The Last Emperor" and would have been seen as the greatest heavyweight ever (at the time). Instead, he jumped right into an overhand right which instantly sent him unconscious face-first into the canvas. MMA is a cruel and unforgiving game, especially at heavyweight.

The brutal loss was just the first in a four-fight skid. After Affliction folded, Arlovski went to Strikeforce and lost three straight, including a 22-second TKO and a brutal knockout at the hands of Sergei Kharitonov.

It looked like Arlovski's time at the upper end of the division had come to an end, as the Belarussian bomber simply couldn't handle the heat being thrown back his way.

Undeterred, Arlovski instead rebuilt himself as a much more conservative fighter, picking his opportunities wisely and mixing in his underappreciated grappling and clinch game alongside improving his striking defense. While it wasn't as regularly exciting as his previous bouts, he was keeping his chin out of harm's way and scoring finishes later in fights as he took advantage of the notoriously weak cardio of most heavyweights. The style even earned him a beautiful head kick KO of 300+ fight veteran Travis Fulton with just a single second left to go in their fight, almost negating the 14:59 of tedium preceeding it.

A fourth bout with Tim Sylvia, who was now out of shape and far past his prime, saw Arlovski dominate before the bout ended via No Contest thanks to an illegal soccer kick over in One FC. Two more wins preceeded a bout with Anthony "Rumble" Johnson, who moved all the way up to heavyweight to fight Arlovski in the WSOF. Arlovski was cracked early and had his jaw broken by the heavy-handed bomber in the opening round, yet miraculously managed to survive and showed the heart of a lion in making it to a hard-fought decision despite the injury.

Two more wins saw Arlovski earn his return to the UFC, where he would take on Brendan Schaub in Vancouver. Schaub was quite the glass cannon himself, so fans expected fireworks and a KO was all-but guaranteed. Nobody told that to the two fighters though, as both were content to make the fight a clinch-fest and avoid any chance of getting knocked out; Arlovski took home a dull split decision that went over with fans like a fart in the wind.

Getting his return out of the way, Arlovski went to work, knocking out Bigfoot Silva to avenge an earlier decision loss back in Strikeforce. He would then beat the daylight out of Travis Browne in a slugfest which saw Arlovski rock Ronda Rousey's future husband on multiple occasions (including once via a brilliant back fist) before the ref eventually saved Browne from further punishment.

A decision win over a similarly resurgent Frank Mir saw Arlovski get another crack at the UFC heavyweight title, something that seemed impossible if you had seen Arlovski's Strikeforce run just a few years prior.

A good boxer who can find an opponent's chin isn't a good matchup for Arlovski however, and Stipe Miocic defended his title with ease in just 54 seconds. The loss would kick off another skid for Arlovski, this time a career low 5-fight losing streak which saw him get knocked out brutally in two of those bouts, against Alistair Overeem and Francis Ngannou.

From there Arlovski would move camps and sharpen his offense to avoid getting caught up in firefights, as well as improving his lackluster defense. He won two decisions before dropping four in a row, though two of those arguably should have gone his way and one was later overturned to a No Contest due to his opponent failing a drug test.

Facing being cut by the UFC, Arlovski came back in the best form we've seen him in years in a rematch against Ben Rothwell. Looking reinvigorated, Arlovski was firing off brilliant combos and thudding kicks, keeping up a significant pace (especially for a heavyweight) and putting a beating on the durable slugger. Though he wasn't able to replicate his 2008 KO, Arlovski took home a dominant decision win and proved the old man still had something left in the tank.

At least against fighters more on his level.

In his last outing, Arlovski faced Jairzinho Rozenstruik. Rozenstruik was 8-0 in MMA with 7 knockouts, but was more known for his work in kickboxing: the Surinamese striker sported an impressive 76-8 record in the sport with a whopping 64 knockouts. His presence in the UFC was immediately felt in his two fights for the organization, which both resulted in highlight reel knockouts and one took just 9 seconds.

Arlovski was simply no match for the seasoned striker and he was dropped by a comically short left hook as he rushed in. Luckily, Rozenstruik didn't deliver an extra blow and Arlovski never completely lost consciousness in the 29-second affair.

Arlovski has had a career filled with ups and downs - he has experienced the highest of highs as a champion in the UFC and delivering some of the most memorable knockouts in the sport, but he has also experienced the lowest of the lows as he's been on the receiving end of many such knockouts and suffered from lengthy losing streaks.

He was the first true glass cannon in MMA and easily one of the most successful. He endured two decades of the brutal sport, reinvented himself on multiple occasions and always handled himself admirably and with respect for the sport and his opponents. Hopefully he finally hangs them up while he still has his wits about him and can reap the rewards of a lucrative career.

2. Melvin Manhoef MMA: 32-14-1 2NC (29 knockout wins, 5 knockout losses)

Kickboxing: 38-14 (27 knockout wins, 6 knockout losses)

If you could take pure violence and conjure it into physical form, that form would look a lot like Melvin Manhoef.

Standing at just 5'8 and being able to make welterweight in MMA (170 pounds), Manhoef isn't the biggest guy but his power is downright sickening. Never backing down from anyone regardless of weight class, Manhoef has fought in every division north of 170 pounds and spent much of his kickboxing career as a heavyweight despite his massive size disadvantage.

What he lacks in height and reach he makes up for with explosive speed and bone crunching power.

Manhoef was raised in the Netherlands and the Surinamese native quickly took to the Dutch style of kickboxing - fast and powerful combinations with the hands alongside powerful leg kicks and body work. Coming from kickboxing, he also kept himself extremely busy, as you can see by his records which combine for over 100 fights (and counting).

It would take many more pages to go through Manhoef's entire career, so instead I'll leave you with the basics.

Manhoef is all-offense, all the time. While perfectly capable of fighting technically, Melvin would much rather wing wild hooks and try to take his opponent's head clean off than engage in a tactical skirmish with anyone. When he lets his hands go he is a whirling dervish of fistic fury, and when he connects, he doesn't just knock people out, he sends them to another dimension.

To give you an understanding of just how hard this man can punch, he knocked out the famously granite-jawed Mark Hunt in just 18 seconds at heavyweight.

Go spend some time looking up "Melvin Manhoef highlights" on Youtube and you will be treated to a wide assortment of vicious knockouts. His takes the Dutch style of kickboxing to the extreme - crippling low kicks combined with flurries of punches and little else. While this makes him somewhat limited against top fighters, the threat of his power and his steady improvement in grappling defense is more than enough to beat most fighters that get locked into the cage with him.

His imposing power has even had several fighters literally run away from him in the middle of a fight. And honestly, I can't blame them.

Even at 43 years of age with a career starting way back in 1995, Manhoef is still competing and is still capable of putting anyone to sleep. He fought for the Bellator middleweight title just a few years ago in 2017, and in that same year beat legendary heavyweight Remy Bonjasky in a kickboxing match (which he fought surprisingly technically in).

Of course, as with all the fighters on this list, Manhoef doesn't have the strongest defensive acumen.

His all-offense style leaves him dangerously exposed quite frequently, and considering he often fought against much larger men, that combined to make for some brutal results. The damage he took in those fights earlier in his career at heavyweight in kickboxing undoubtedly hampered his ability to take a shot later on. Especially when that shot is flush on the chin because his wild aggression leaves him helplessly open for a counter.

Often Manhoef's knockout losses come when he has his opponent hurt and then chases his target, forgetting entirely about defense and focusing completely on murdering his prey (which he admittedly does accomplish quite often). One of his most famous losses came at the hands of Ruthless Robbie Lawler in Strikeforce.

It looked like it was only a matter of time before "Ruthless" Robbie was another of Manhoef's victims; Melvin's brutal leg kicks were already causing Lawler to limp and continuously stumble off balance just minutes into the fight. One such leg kick completely took away Lawler's base, but instead of putting him out of position to throw back, which is what Melvin undoubtedly thought as he stepped forward, Lawler hunkered down from his new position and threw a hail mary right hand out of his opposite stance which put Manhoef on ice in an incredible come-from-behind KO.

While Manhoef's thrilling style limited the heights that he could reach in both kickboxing and MMA, it's that same style that made him such an incredible fighter to watch and earned him a ridiculous body count.

He is one of the best knockout artists in combat sports history and inarguably one of the greatest glass cannons to ever grace a cage (or ring). Even at 43 he's still going strong, though hopefully he'll call it a day sometime before he suffers much more brain trauma for his efforts.

1. Alistair Overeem

MMA: 45-17 1NC (23 knockout wins, 13 knockout losses)

Kickboxing: 10-4 (7 knockout wins, 3 knockout losses)

There could be only one.

No heavyweight in MMA history has the same level of offensive skill as Alistair Overeem. His legendary knees are absurdly vicious, his kicks crack like a whip, his hands are heavy and his offensive boxing is sharp. He carries concussive power with all "eight" limbs in Muay Thai; both hands, both elbows, both knees, both shins. He is simply put the most talented and offensively technical striker the heavyweight division has ever seen.

Unfortunately for the Reem, his defensive capabilities are not nearly as impressive.

The lanky 6'5 Dutchman started his career way back in 1999 at the age of 18, competing in both kickboxing and MMA bouts in the Netherlands and Japan at light heavyweight. While he would dabble in kickboxing matches over the years, his primary focus was MMA and after racking up 9 straight wins he would venture to Japan to compete in the beloved PRIDE organization. There, the rangy "Demolition Man" would earn his stripes and garner a following thanks to his exciting style.

While his hands weren't particularly noteworthy at that weight, his knees were vicious and his submission game was very impressive. He continued to rack up wins and scored a variety of different submissions, cementing himself as a finisher no matter where the fight went. He even scored submission wins over MMA legends Vitor Belfort and Igor Vovchanchyn to place himself amongst the elite in the division, but when under fire from top-tier fighters he looked uncomfortable and his chin didn't hold up well.

Despite compiling an impressive resume of wins, Overeem often stumbled against stiff competition. Future UFC champion and legend Chuck Liddell iced Overeem in his journey over to Japan, Mauricio Shogun Rua scored an easy ground and pound TKO over him, and in mid-2006 Alistair started a three fight skid with all three losses being by knockout/TKO (albeit to very good fighters), capped off by Shogun's famous diving punch which starched the underpowered Dutchman in their rematch.

With his career momentum ground to a halt, the 6'5 lanky light heavyweight opted to stop cutting weight and instead move up to compete against the behemoths at heavyweight. He slowly began packing more muscle onto his frame, and it saw some positive results quickly, with a submission win in MMA and a KO victory in kickboxing coming in mid-2007. Unfortunately, that inability to take punishment saw him get viciously knocked out and sent through the ropes by Sergei Kharitonov in their rematch at heavyweight, who he had previously beat by TKO stemming from his powerful knees.

But Overeem was in a bulking phase. Fighting overseas where "supplements" weren't tested for and were even actively encouraged by some promoters, "Ubereem" was beginning to form. Where once stood a gangly 205-pounder now stood a mass of rippling muscle, his head getting visibly larger as his traps soon looked like they were hiding soccer balls underneath.

Hilariously, when asked about his size gains Overeem claimed that it was due to his high-protein diet consisting of ample amounts of horse meat, a common delicacy over in Holland. Fans of course knew that the only way horse meat was the key to his size was if horse meat was the code name of some new designer steroid, and new slang for juicing in MMA was born. But when you fight like Ubereem did and mesmerize crowds with your brutality, a little "extra" supplementation is largely ignored by most fans, especially when drug testing wasn't even enforced.

Just two months after his crushing loss to Kharitonov, Overeem looked ridiculously jacked as he absolutely crushed Paul Buentello to capture the inaugural Strikeforce heavyweight championship title stateside. After a sizeable layoff (for a man who fights as frequently as he does at least) Overeem returned overseas mid-2008 and continued his career rebirth.

Now dubbed "Ubereem" by fans, the Demolition Man's new form combined with his already superb finishing ability was simply overwhelming to opponents. Picking up three wins with ease, including an Americana submission over Mark Hunt, Overeem would get his biggest opportunity yet: a fight with kickboxing superstar Badr Hari on New Year's Eve in Japan, the biggest night for combat sports in the country.

It was billed as MMA versus kickboxing and the kickboxing world didn't take too kindly to an outsider being given such a massive opportunity when he had just a 2-2 record in that sport at the time.

Ubereem however gave zero fucks what they thought.

Alistair shocked the world by absolutely crushing the kickboxing ace, battering him and dropping him with a knee and follow-up shots before knocking him dead with a left hook just over two minutes into the bout.

Early in the new year Overeem held his own but dropped a decision to kickboxing legend Remy Bonjasky, with many fans bringing into question whether his Badr knockout was a fluke. Beating another legend in Peter Aerts silenced those critics however, and earned him a spot in the top eight of the 2009 World K1 Grand Prix. After picking up a few sub-90-second submission wins in MMA to keep busy, Overeem made his way to Yokohama to compete in the one-night finals of the tournament.

His first fight that night sent chills down the spine of everyone watching as he flatlined Ewerton Teixeira with a vicious knee in the opening round. With Badr Hari securing a 38-second KO of his own, the stage was set for an epic rematch in the semi-finals of the Grand Prix.

Unfortunately for Ubereem, even his massive frame couldn't hide his chin from the scorching heat thrown by kickboxing's premier knockout king. Hari dropped him early and continued to throw bombs as Overeem desperately tried to hang on. As it was in a one-night tournament, receiving two knockdowns in the same round was ruled a TKO; stumbling back from Hari's onslaught, Overeem was caught by the ropes which counts as a knockdown, thus earning Badr his revenge. On the positive side, Overeem wasn't starched outright like he often was in the past, so that was an improvement.

It would be the last time Ubereem lost.

Fighting later that same month, Overeem ended his year on a high note with a savage murder of Kazuyuki Fujita in Japan.

Splitting time between the two sports in 2010, Overeem would post his best ever results, going a total of 7-0 that year. In MMA, he mauled Brett Rogers to defend his Strikeforce heavyweight title, which he had held for 3 years before returning to the promotion. He also murdered Todd Duffee, another notable glass cannon on this list, in just 19 seconds.

It was in kickboxing that Ubereem reached entirely new heights however.

Securing his entry into the 2010 K1 World Grand Prix by way of one of his notoriously lethal knees, in the final 16 he demolished his opponent with three straight knockdowns in just over two minutes. Ubereem was in his prime and would not be denied the Grand Prix twice in a row.

In the three-fight, one-night Grand Prix final eight, Overeem overpowered kickboxing star Tyrone Spong to earn an easy decision win. In the semi-finals, Turkish legend Gokhan Saki had his arm snapped in half blocking one of Ubereem's kicks. Nobody could withstand the power that Ubereem was packing that night, and in the finale, a 39-year-old Peter Aert's had managed to claw and scrape his way to an unlikely tournament final berth; he was mercilessly executed for his efforts.

Overeem captured a K1 World Grand Prix title that night, the most coveted accomplishment in the sport of kickboxing. From there, Overeem would turn his attention back entirely to MMA, this time on the western front.

Returning to Strikeforce, Overeem ragdolled Fabricio Werdum en route to an easy decision win to avenge a 2006 submission loss to the Brazilian submission ace back in PRIDE. It put him into the semi-finals of the Strikeforce Heavyweight Grand Prix, but it was also the last fight on his contract: everyone knew the best fighters in the game competed under the Zuffa banner, not Strikeforce.

Overeem signed with the UFC shortly after, and a mega fight with former champion Brock Lesnar was immediately made. When the two met at UFC 141, it looked more like a public execution than a fight.

Lesnar of course was no stranger to juicing, putting the two juggernauts on an even playing field. Lesnar's doping even led to severe illness - diverticulitis, which is what sidelined Lesnar after his first title defense as well as after his last outing against Cain, is a rare form of colitis that is virtually never found in non-elderly people that haven't used steroids.

Unlike Overeem who also sported excellent technical prowess and ability, Lesnar's primary weapon was his size and strength. When placed against someone who more than met his level in that department, the massive skill differential became apparent.

While it was billed as "the unstoppable force meets the immovable object", in reality the immovable object was tossed around the cage like it were a small child. Ubereem easily shucked off Lesnar's attempts at a takedown and Brock's confidence quickly turned to visible fear as a hulking monstrosity plodded toward him, Brock's flailing jabs not even drawing a reaction from his unflinching executioner.

Ubereem was a particularly cruel beast - after having an extended layoff due to surgery required thanks to his diverticulitis, Lesnar's repaired midsection was smashed by several nasty knees. Lesnar did his best to tough it out but Ubereem was relentless. More knees sent Brock reeling before a disgusting left kick directly to the gut sent Lesnar to the floor, covering his head as Overeem peppered his massive forearms with little shots to entice the referee to stop it. While the ref hesitated, Ubereem took one last shot at Brock's midsection, nailing him with a sadistic uppercut to his exposed midriff as he sat hunched against the cage in pain.

The fight was so vicious it sent Brock immediately back to the WWE. The one sided mauling was so dominant, even Cain Velasquez's destruction of Lesnar looked competitive by comparison.

Scheduled for a massive showdown against heavy-handed boxing specialist Junior Dos Santos for the UFC heavyweight title, the MMA world was abuzz with anticipation for the gigantic matchup. Unfortunately, the fight would be scrapped and Ubereem was never to be seen again. After a 13-fight unbeaten streak in MMA and 5 straight dominant wins in kickboxing, with all but two of them ending via some form of finish, Ubereem was no more.

Following a pre-fight press conference in Las Vegas, the Nevada State Athletic Commission opted to surprise the top fighters on the card (including Dos Santos and Overeem) with a random drug test. Overeem was very surprised.

Shocking no one, Ubereem's sample came back positive for an elevated testosterone-to-epitestosterone ratio (the maximum limit was 6:1, his was 14:1 which indicates use of synthetic testosterone) and his title bid was axed. While he came up with an excuse that the result was due to a medication a doctor gave him for inflammation, it confirmed what fans already knew for years. Since he hadn't yet received his license to fight, the commission merely made him rescind his application and wait 9 months before being allowed to re-apply, essentially suspending him for 9 months (the standard penalty at the time).

Overeem would come back in 2013 sporting a much less imposing physique. His appearance had certainly deflated from the Ubereem form fans had grown accustomed to - while he was still a large man and weighed around 250, his mass of muscle was now mixed with flab that gave him a considerably softer look. Facing Antonio Bigfoot Silva for his return, Overeem was still expected to run over the considerably less skilled and slower fighter.

While a deflated Overeem didn't carry the same sense of invulnerability he once did, his softer form was still handling his outmatched opponent at UFC 156 just fine (who ironically was on perfectly legal testosterone replacement therapy at the time). Landing potshots at will, Overeem avoided returns by tripping and throwing his larger opponent to the mat whenever Bigfoot got close, and tying him up where he held an advantage in the clinch.

For his part, Silva bided his time and executed a surprisingly intelligent gameplan. While he did take some punishment on the feet, Bigfoot continued to pressure Overeem throughout, constantly walking forward and even though he wasn't accomplishing much offensively, most importantly he was making Overeem constantly work. Overeem's gas tank was never the greatest, but coming off of whatever "supplements" he was taking and constantly being pressured combined to systematically sap Alistair of his energy reserves.

In the third, Bigfoot ramped up that pressure and a fading Overeem was no longer able to force him down to the floor to relieve the pressure. Overeem kept trying to tie up but wasn't able to hold Bigfoot there any longer, and now Silva started to land his cinder block-sized fists on Overeem's face.

A series of right hands backed Overeem to the cage and a vicious combination put him out on his feet - several more massive shots continued to rattle his cranium before his unconscious corpse collapsed and the ref finally stepped in. It was a nasty finish and the Ubereem chapter of Alistair's career was officially closed.

Later that year he would return to action against Travis Browne - Overeem hurt Browne badly with his trademark knees early, going to town on his prey and coming extremely close to earning a finish. Browne, who was remarkably tough at the time, managed to survive the assault and claw his way back into the fight, and at that point, Overeem had already expended his gas tank searching for an early finish. Browne threw several front kicks to the body which Overeem seemed content to ignore, only to switch targets to the head and put Overeem on his backside. Just like that, Overeem's aura of greatness had completely evaporated.

A workmanlike, thorough beating of Frank Mir, which saw Overeem not only willing to engage the submission specialist on the mat but to actively take him there, earned Overeem a rare decision win and put him back in the win column, showcasing his well-roundedness to UFC fans that had yet to see Overeem's grappling and rounded skillset in action.

Next he faced Big Ben Rothwell - Overeem's habit of ducking in to clinch opponents in anticipation of a right hand got him into big trouble early here, as Rothwell timed him with an uppercut that put the Dutchman in survival mode. Shortly after, Overeem threw an ill-timed overhand left from southpaw that saw him eat an overhand right in return, and Overeem went from an incredibly dominant run to suffering three brutal knockout losses in his last four outings.

It was time for another rebirth; it was time for Econoreem.

Reinventing himself was always one of Overeem's strong suits, and it was time for a new approach. Rather than meeting power with power, Overeem instead looked to focus entirely on his mobility and cardio, using his well-rounded toolset to chip away at opponents and avoid punishment in return. This new version would be dubbed by fans as "Econoreem".

Getting back into the cage just 4 months after his last loss, Overeem took down the rangy Stefan Struve and knocked him out with sickening ground and pound. He then battered Roy Nelson en route to a lopsided decision win, showing off the afforementioned improved endurance along the way.

We then finally got to see his monumental clash with Junior Dos Santos - albeit a few years late - and it was Overeem who triumphed, landing a brilliant left corkscrew uppercut to put the Brazilian boxer down for the count in the second round. Overeem was back in a big way and he was running roughshod through the division, proving the doubters who said he was done wrong.

Andrei Arlovski was his next victim, who he knocked out with a beautiful crane kick followed by an overhand left from southpaw in a brilliant display of stringing together stances and very different techniques. Several years after his initial UFC contendership bid, Overeem finally got his title shot.

Econoreem employed a peculiar strategy against the wrestle-boxer in his home state of Ohio - staying completely at range, Overeem avoided exchanges entirely and even turned his back to run away from champion Stipe Miocic. Stipe quickly grew frustrated and the trap was set - while Stipe angrily stomped forward expecting another retreat, Overeem instead got back into stance and blasted him with a straight left. The shot put Miocic on his ass and Overeem swarmed, victory well within his grasp - but instead of looking for the knockout, Overeem tried to submit Stipe with a guillotine instead. The mistake proved fatal, as Stipe was able to survive the choke and work his way back to his feet.

Overeem tried to get back to employing the same strategy, but Stipe was having none of it. Taking him down immediately, Stipe stood over him and landed a shot through Overeem's guard that put Alistair unconscious, and just like that, Overeem's long overdue title slipped through his fingers. Instead of looking like a brilliant tactician had he been able to capitalize on his moment of advantage, his running-filled title contest looked like a massive strategic blunder.

Undeterred, Overeem went on to viciously flatline Mark Hunt with his legendary knees and won a close decision against old rival Fabricio Werdum.

Nearing another title shot, a massive showdown with vaunted knockout puncher Francis Ngannou ensued. One of the scariest knockouts you'll ever see followed - Ngannou nearly decapitated poor Overeem with a long left hook in the pocket. Overeem was unconscious for a few minutes, and considering the amount of knockout losses he'd had, I was almost convinced I had just witnessed the first death in UFC history.

But like always, Overeem got up, brushed it off, and set his sights on his next bout.

His next fight seemingly spelled the end - looking slow and lethargic, Overeem was easily taken down repeatedly by standout wrestler Curtis Blaydes. It looked like age had finally caught up with the 38 year old, and in the third round he was viciously finished with a series of elbows that also opened up a wicked gash on his forehead. It was a sad day for Overeem fans, and theMMA community urged the popular knockout artist to retire.

But retire he didn't - Overeem stated his performance was hampered by a knee injury and came back to prove it by knocking out a young Russian prospect in his next outing, smartly taking his opponent down and pounding him into oblivion with his patented brand of ferocious ground and pound. He then went on to fight fellow vet Alexey Oleynik in Russia, blasting him repeatedly in the clinch with elbows and his hellacious knees for a first round finish.

Unfortunately for his next outing, he'll be taking on the undefeated kickboxing standout Jairzinho Rozenstruik on December 7. It's an extremely dangerous fight for Overeem given his tendency to get knocked out and Jairzinho's ridiculous power, but if there's one thing for certain in an Overeem fight, it's that anything can happen. He is capable of knocking out anybody on the planet at any moment, just as he is capable of getting knocked out even by inferior fighters at any moment. That's about the purest definition of a glass cannon there is.

As an important sidenote, Alistair Overeem is a physical oddity. He gets knocked out, he suffers brutal losses, but he always comes back and looks no worse for wear. Despite a two decade career and a whopping 16 KO/TKO losses, he seems to suffer no ill effects from all that damage - he still speaks well and hasn't showed any signs of slurred speech or confusion which is common with "punch drunk" fighters, he still moves well and can compete at the highest level athletically, he shows no sign of decreased coordination and claims to suffer no ill side effects from the concussive damage he's taken over the years.

With CTE such a prevalent issue in combat sports and contact sports in general, scientists would be wise to run a battery of tests on Overeem - there must be some sort of scientific reasoning behind his ability to receive so much brain trauma and yet continue to function at such a high level and show no outward signs of damage. Scientists have already theorized that certain genes or mutations could explain why some people can suffer so much from even a single concussion while others suffer no or little ill effects even after many of them - whatever that gene or mutation is, you can be sure Overeem has it in spades.

With his style and offensive capabilities, combined with his fragile chin and often porous defense, Alistair Overeem is the greatest example of a glass cannon in combat sports period.

He is the most accomplished striker to ever compete in the sport and has put together one of the most impressive resumes in MMA history over twenty years of competition. He is one of the most entertaining fighters to watch as a result and has continued to reinvent himself and evolve as a fighter to this day.

Alistair Overeem truly is a legend in the sport and here's hoping that when he eventually decides to call it a career, he can enjoy the fruits of his labour and isn't a slobbering vegetable.

Honourable Mentions

Pat Barry: 8-7 in MMA (7 knockout wins, 4 knockout losses), 17-6 kickboxing (10/2)

Brendan Schaub: 10-5 (7 knockout wins, 4 knockout losses)

Cody Garbrandt: 11-3 (9 knockout wins, 3 knockout losses)


bottom of page