If nine has proved to be the point of mortality for Beethoven, Schubert, Bruckner and Mahler, then six looms in snooker's mythology. Ray Reardon and Steve Davis have won the modern world championship six times and Stephen Hendry is on that number. A seventh, and numerical verification of his position as the greatest snooker player of all time, has been his ambition and his incentive.
The World Championship begins at the Crucible today, with the 28-year- old Hendry's pursuit of his seventh title the overwhelming theme.
"I'm going to be trying so hard in Sheffield," he said, "that if anyone wants to beat me they're going to have to scrape me off the table."
Hendry, at his best, is untouchable but, if you had to pick a test designed to topple the man who has won the title five times in succession, then the one facing him is it.
He begins today with Andy Hicks, a semi-finalist in 1995, and he is then scheduled to meet Mark Williams, who beat him 9-2 in the final of the British Open two weeks ago. Waiting in the quarter-finals should be the great unpredictable: Ronnie O'Sullivan.
Fatigue as much as form might prove Hendry's weak spot, but he does not mind who he plays. "Being at the Crucible is incentive enough," he said.
However, if Hendry cannot extend himself again, where is the next champion? The 21-year-old O'Sullivan is in with a shout, although his appetite is open to question. He indicated that he would retire during the European Open, but stayed on, explaining: "It wasn't the first time I've said I'll quit and I don't suppose it'll be the last."
Last year, O'Sullivan seemed like a car going too fast towards a tight corner. He was offensively rude to Alain Robidoux and later assaulted a press officer while riding the roller-coaster of his personality into the semi-finals. You need mental rigidity to win at the Crucible, and his is always suspect. How he would react if he did beat Hendry in the last eight is anyone's guess.
The other side of the draw provides more solid threats to the reigning champion. Peter Ebdon, last year's runner-up, has the talent and, he hopes, the endurance to upset Hendry, but also lurking are Steve Davis and John Higgins.
The transformation of Davis from the player everyone wanted to see beaten into the ageing favourite carrying the hopes of the romantics is a tribute to what failure can do. The 39-year-old former champion confounded everyone by taking the Benson and Hedges Masters in February when success seemed improbable. Lightning is unlikely to strike twice, no matter how popular it would be, and Higgins will have to be overcome in the quarter-finals.
Twelve months ago Higgins was everyone's choice as Hendry's potential nemesis, but his light has faded. The 21-year-old Scot had to change his cue in January and has since won the European Open, although his recent form has left him and his admirers feeling short-changed.
"It's been an OK season for other players," he said, "but after the standard I've reached over the past two years I demand more of myself. I need to get my finger out for the Crucible. Give it my best shot. If I play well, I'll have a hell of a chance."
So will Hendry and, as throughout the 90s, his personality will dominate the tournament. A magnificent seven beckons.