An ability to remain poised, disciplined, and committed to a gameplan even under adversity is certainly one of the most important traits in setting the elites apart from all the rest. Indeed, it may be THE most important trait. So who were some outstanding fighters who fell short of the elite class because they lost concentration mid-fight or came unraveled or lost composure under difficult circumstances. Before he was an elite trainer, Robert Garcia was a very, very good fighter, but his tendancy to get rattled by cuts and constant pressure cost him three defeats, all in fights he was winning hands down before getting stopped. Zab Judah springs to mind, as well as Julio Diaz, who was in a position to win his biggest fight against Jose Luis Castillo if he'd kept his cool after getting slice up. Jhonny Gonzalez could box like a Mexican reincarnation of Harold Johnson in the early rounds of a fight and then come unstuck without warning and walk into a fatal, fight changing punch. It happened against Nishioka, Penalosa, and Vasquez. Wladimir would have been the poster child in this category back when he was a post-Sanders basket case. But after being resurrected by Steward he improved considerably in this area. Any others?
What about Prince Hamed? Never recovered from that ONE loss. Andrew Golota springs to mind during his first fight with Riddick Bowe. He was boxing the **** outta him and coulda won, but all of a sudden he screws himself with the illegal blows.
Jerry Quarry was one who lacked confidence and got rattled readily. Once he got tagged, he dropped his game plan and would get beaten.
The Korean fella who got stopped by Limon and Navarette was World class but folded under pressure. Alfonso Lopez cpukd unravel under pressure despite world class skilks and world class victories (Oguma for one) Pressure was the downfall for Cotto against Margarito and Pacquiao. Clotteys forward movement made Cotto ragged even though his punch output was poor.
Golota might be king in this category. Quarry is a great answer too. He seemed to phase out mentally in the first Frazier fight around round three when its clear his blitz strategy wasn't working. If he'd kept a cool head and focused on tightening up his defense, locking Frazier up in clinches up close, and getting his shots going in two and three punch combinations at long range, he could have feasibly won.
I agree with Golota. I've heard that he was unbeatable in the gym and looked amazing. But when it actually mattered his nerves always got the better of him
Tommy Hearns. He was being tested by feather punching Harold Weston and was lucky Weston had to quit due to a damaged eye. He couldn't handle Leonard, Hagler or Barkley when he was hurt. With his height and reach advantage, if he had kept his head and boxed smarter, he may have been able to win all of those fights.
A perfect answer is Dempsey .. when ht he saw red and slugged away, a strategy that would have spelled murder against the best of the best, some of who he had skills to defeat if he was able to keep a calm head ..
Tyrone Jackson, a junior-lightweight contender who simply froze on the big stage. He was stopped in six by some Korean guy whose name I forget, and then on national TV against Tony Lopez he just stood there for eight rounds while hardly throwing a punch. He was stopped in eight in a performance where you cringed in embarrassment for the guy. I've never seen a choke job quite like that.