Recent events have proven that for Floyd Mayweather Jr, retiring from boxing does not reflect any desire to retreat from the public eye. Re-igniting the tired feud with Conor McGregor, the man known as ‘Money’ posted a short video of himself stepping into an MMA cage, creating speculation that he might be returning as a competitor in the UFC. Just as the Irishman’s spell between the ropes ended predictably in defeat, Mayweather’s chances of finding glory in the Octagon should be similarly slim. Nevertheless, the history of crossover fighters is a chequered one. There have been some remarkable successes to accompany those ill-advised and occasionally comedic failures. Let’s remind ourselves of some boxers who have braved the frontiers of alternative combat sports, and those who have taken on our challenge from elsewhere in the fighting landscape.

The Good…

Holly Holm: Boxing, Kickboxing, MMA.

It should not be controversial to say that Holly Holm may well be the greatest crossover fighter of all time. In addition to her status as a national amateur kickboxing champion, Holm is the only athlete to become a world champion in both boxing and the UFC, the latter being the pinnacle of mixed martial arts achievement. In perhaps her greatest moment, she made headlines with her jaw-dropping upset of previously undefeated superstar, Ronda Rousey. Rousey was featured in one of Sly Stallone’s popular movie franchises, but against Holm, only her chin was shown to be expendable. After having her notorious ground game neutralised, ‘Rowdy’ finally succumbed to a left cross, left head kick combination which highlighted Holm’s multi-platform proficiency in a brutal and spectacular fashion.

Ray Mercer: Boxing, Kickboxing, MMA

He looked almost like a man getting off the armchair to satisfy a mid-life crisis, but in 2009, the 48-year old Mercer made his way to Alabama, in order to take on former UFC Heavyweight Champion Tim Sylvia in a cage fight. Those in attendance at the bombastically named ‘Adrenaline MMA 3: Bragging Rights’ could not have expected what was to come. With the opening bell almost still audible, Sylvia was rendered prostrate on the floor. Power is famously the last thing to go, and Mercer’s was only amplified with the transition down to 4oz MMA gloves. The 1988 Olympic Gold medallist and former WBO Heavyweight champion lived up to his nickname one last time, ‘Merciless’ as he put everything into one devastating punch. He had been unsuccessful as a kickboxer and had lost in an exhibition MMA bout to the late Kimbo Slice, but after demolishing Sylvia in such a dramatic manner, Mercer finds himself on this side of the judgment. He never fought again following the bout, riding off into the sunset and cementing his status as an all-around badass.

The Not so Good…

James Toney: Boxing, MMA

James Toney is fairly recognised as one of the most aesthetically pleasing boxers of all time. His old-school defensive mastery and sharp counterpunching skill have garnered him widespread admiration and respect. This and his status as a three-weight world champion makes his solitary foray into the world of MMA all the more depressing. After stoking interest with his customary loud-mouthed braggadocio, he was granted an intriguing match-up with another ‘Expendables’ alumni, UFC Legend Randy Couture. The bout was popular enough to land a coveted position as the chief undercard to the UFC 118 main-event. Couture quickly extinguished the excitement once the bell rang, however, cruising to victory with a submission in the very first round. Toney made no impression on the 47-year-old, and the defeat was in equal measures underwhelming and embarrassing. On a platform far higher than Mercer’s victory a year previous, Toney’s loss closed the book for many on whether or not a boxer could find success as an MMA fighter. To these fans, the answer was which hinted by Art Jimmerson’s failure in the inaugural UFC, was a resounding no.

Pele Reid: Kickboxing, Boxing

Let’s get the most important detail out of the way: Pele Reid once knocked out Vitali Klitschko. It was an amateur kickboxing contest, and it was a peach of a spinning back kick, striking Klitschko in the chin and leaving him momentarily senseless. Reid furthered this achievement with his greatest success, winning the WAKO World Championship in his weight class (-89kg) in 1993. His professional kickboxing record is elusive but appears less impressive, however, he ends up on this side of the article for his troubled transition to boxing. Simply put, Reid did not live up to the high expectations that were placed on his broad shoulders. He showed tremendous power at a lower level, however, as highlighted by his 3rd round knockout loss to Julius Francis for the British title, he could not live with the best in the domestic scene. Finishing with a 20(17)-6(5)-2 record, he unquestionably had a respectable career in both disciplines, but his boxing exploits proved that he would have been better served with drop-kicks in his repertoire than dropping kicks from it altogether.

Some possess the will to prove themselves as the best overall fighter on the planet. Others are pursuing lucrative business moves. A few, it seems, are just good ol’ fashioned crazy. Whatever causes them to dive into different disciplines, crossover fighters can produce a healthy dose of entertainment and intrigue. There are plenty more examples to be covered on another occasion, but in the meantime, as they say in wrestling: Don’t try this at home!