SNOOKER: He can become an angry young man when it all goes wrong on the table, but now Stephen Maguire is trying to master his emotions, finds David Hendon

As a boy growing up in Glasgow, Stephen Maguire kept a tankful of baby sharks in his bedroom. Now 27, he is one of the biggest fishes in snooker's pond with a fierce competitive spirit that has, at times, threatened to be his undoing.

Maguire began this season second behind Ronnie O'Sullivan in the world rankings and is among the favourites to win the Royal London Watches Grand Prix, which got under way at the SECC in Glasgow yesterday.

Spectators will not have to be experts in body language to discern what Maguire is thinking if things go wrong. Unlike many of snooker's poker faced stars, he is known for his expressive, at times aggressive, reactions to missed pots and unforced errors. The table rail has been met with his clunking fist on more than one occasion. At last season's World Championship, he broke a tile in his dressing room between frames after failing to complete a maximum break.

Off the table, he is far from an angry young man with a grudge against the world. On the contrary, he lives a quiet, happy life with his partner, Sharon, and their baby son, Finn.

But when things go wrong on the green baize, it is best to stand back.

"Terry Griffiths was my coach for four years. For the first three he was always telling me not to show any emotion around the table, to be like Steve Davis and not show anything," Maguire said. "But it didn't work. I was holding everything inside. I couldn't play because I was thinking about it so much. We sat down and Terry said that if I had to show emotion, I might as well do it right away and get it over with. Sometimes I get embarrassed with the way I'm starting to cue and smack the table. It gets it out of my system and if I get warned by the referee I'll take it because it doesn't really matter. The crowd come to see good snooker.

"It's hard when you're struggling because people have paid good money to come and watch you play. Over the last couple of years I've tried to be calmer because I don't want my wee boy to see me acting like that."

Maguire spent his teenage years practising with Stephen Hendry when his compatriot bestrode the snooker world. He turned professional in 1999, at 19 became the youngest player to make a competitive 147 and quietly rose up the rankings.

Maguire was 48th in the world when he won the 2004 European Open, his first ranking title, and played about as well as anyone can to win the UK Champ-ionship at the end of that year. En route, he had beaten O'Sullivan for the second time in three weeks, leading the Englishman to predict he could dominate the game for the next 10 years.

However, for two years, results dried up. Maguire looked as if he had peaked and was unable to adapt to life as the hunted rather than the hunter. Determined to turn things round, he reached three finals last season, winning the Northern Ireland Trophy and China Open.

Maguire accepts, though, that O'Sullivan is currently in a league of his own. The world champion was taken to deciding frame finishes three times in the season-opening Northern Ireland Trophy but, such is his aura of invinc-ibility, nobody could beat him.

In the Shanghai Masters semi-finals a week ago, Maguire led O'Sullivan 5-4 but badly misjudged an attempted pot and did not score another point in the match.

"Ronnie's the man to beat at the moment," Maguire said. "A lot of players are scared to play him and scared to beat him. But that's not his fault. It's the other guy's fault for thinking it's such a big scalp. Ronnie's made his reputation over the years by winning as much as he has."

O'Sullivan has won three world titles. Maguire is yet to capture the sport's greatest prize. He came close in 2007 but was beaten 17-15 in the semi-finals by John Higgins. Last season, he lost 13-12 to Joe Perry in the quarter-finals.

"I want to give the World Championship a good go this season. I want to win it before I'm 30," Maguire said. "If I don't win it by then I could be struggling. Over the next couple of years I'm going to knuckle down and give it my full attention."

Most in the sport would agree Maguire has the talent to be world champion. Dealing with the setbacks that will inevitably occur along the way will be his greatest test.