One evening in the mid-1990s, Manchester United players and staff attended the premiere for a Batman film. It was a black-tie event, but United star Eric Cantona arrived wearing an all-white suit finished off with bright red trainers. His team-mates laughed, while manager Alex Ferguson turned a blind eye.He was perceived as damaged goods in France, but in England he helped Leeds United win the league, and, after his arrival at Old Trafford in the autumn of 1992 he was afforded the freedom to express his eccentricities because of the example he set on the training ground.Cantona was one of the first players under Ferguson to spend hours after a session practising the basics on his own. He was humble enough to acknowledge his flaws and, as captain, help the younger players rid themselves of theirs.But he always maintained a swagger that saw him hold his nerve under pressure to produce moments of match-winning brilliance when his team needed it most, such as the winning goal in the 1996 FA Cup final against Liverpool.His is a story that prompts an interesting question. While physical gifts and world-class skill are key to the success of sport's finest athletes, is a big ego the secret ingredient that elevates good to great?Mike Forde is a firm believer in the power of ego. He spent eight years as performance director at Bolton Wanderers between 1999 and 2007 and a further six as director of football operations for Chelsea.His jobs involved travelling the world, liaising with sports teams from the All Blacks to NFL and NBA franchises.Forde told BBC Sport: "If you're Didier Drogba taking a penalty in the 2012 Champions League final, with 160 million people watching around the world and 60000 stood in the stadium, you need a high level of confidence and self-belief to perform. That is what we characterise as ego."Sports psychologist Bill Beswick, who has worked for Manchester United and England, adds: "Ex-Manchester United midfielder Roy Keane had intense self-belief. He maximised his ego to make the absolute best of himself."We have seen ego manifest itself in Cantona's upturned collar, while Thierry Henry would often raise his finger to his lips when he scored.But in others the same levels of ego are masked.Confidence coach Martin Perry cites the difference between Barcelona forward Lionel Messi and Real Madrid's Cristiano Ronaldo."Ronaldo is very outwardly confident, whereas Messi comes across as quiet and humble, but both have egos. They don't see risks; they have a bulletproof certainty they'll produce, and, when an athlete has that supreme level of confidence, magic can happen."Ego must be harnessed correctly to ensure an athlete steers clear of controversy and continues to develop. Think of Kevin Pietersen's fall from England's cricket team.When talent and ego are in perfect symmetry, a player can make the leap from good to great.Said Forde: "The ego is in place to give them the confidence to perform on the biggest stage and then there's coachability and this intrinsic DNA that gives them the desire to be the best version of themselves."..