Naturally, all these attributes are devalued if the man in the No 10 shirt is slow off the mark; he must have a poacher's eye for the main chance and, while Olympic sprinting speed is not a must, the ability to accelerate over those first 10 defence-splitting yards to turn a half- chance into a try-scoring break certainly is. He must also possess that elusive, uncoachable quality known as "vision" which elevates the true artist above the mere artisan.
He cannot be good just going forward - that would make him a girly fancy- dan in the eyes of his forwards. Our man must be strong and sure in the tackle too. Above all in a position where judgment is everything, he must have the nous to know when to do what and to make sure that his team-mates are on the same wavelength; it is no use being Barry John if the man outside you is more John Smith than John Dawes.
An unapproachable counsel of perfection? Perhaps, but in this World Cup there is a player who measures up to all these criteria in almost every respect: Stephen Bachop of Samoa. We all know about Samoans - they are tough as teak and run like the wind. But while Bachop has all his native land's stereotypical rugby characteristics, the pivotal role he played in London Irish's resurgence last season confirmed him as both disciplined and tactically astute.
The Exiles' director of rugby, Dick Best, is not a man given to extravagant praise. Indeed his deliberate, deadpan manner is allied to a vocabulary where the words "not bad" count as a ringing endorsement. But switch the subject to Bachop and the former England coach is, by his standards, glowing in his appreciation of the 33-year-old fly-half.
"We wanted to play 15-man rugby and Stephen fitted in perfectly. He's one of the best passers I've seen. I watched him in the Super 12 with Wellington and was impressed. Stephen's been around for a long time and his decision-making is excellent. He has so much to offer. Of course, most fly-halves can pass and kick, but not like him. Another strength of his is the way he brings other players into the game.
"Above all he has tremendous vision; he sees things others don't. You can't coach that. I've seen a lot of great fly-halves. But in terms of what he does and the job he's done for us, he's been very good indeed. He's unique. No one passes like him." Best pauses before correcting himself. "Actually the only person who passed like him was Mark Ella" - not so much a qualification as a compliment.
There was concern among sections of the Irish faithful that the influx of foreigners would diminish the club's distinctive character. But at a time when overseas players in many sports stand accused of blocking British talent, Best insists Bachop's off-field contribution was second to none. "He's the senior pro and although he's not unduly exuberant he's very much part of the team. He leads the players' court and is a tremendous role model for the young boys. James Brown, our England Under-21 fly-half, is learning from him all the time."
To judge by this accolade you would think Bachop had a string of international appearances behind him. But, after having a crack at becoming an All Black, Bachop suffered the misfortune of being a contemporary of Andrew Mehrtens. Five New Zealand caps between 1992-1995 were a miserly reward for such a talent. Then came a three-year requalification period for Samoa.
Bachop isn't even the only dual national in his family. Younger brother Graeme, 32, an All Black scrum-half who played alongside Stephen in New Zealand's three-Test series against South Africa in 1994, is now with Japan.
The pair made rugby history when they faced each other on 22 May, the first brothers to be on opposite sides in an international, as Japan surprisingly won 37-34. They could repeat this feat next month at Wrexham, where the two countries will play each other in a pool match.
No one knows anyone quite as well as a sibling. But just as no man is a hero to his valet, equally if you want the truth about a No 10 ask his scrum-half. Kevin Putt, Bachop's Kiwi half-back partner at London Irish, provides a sterling character reference. "He's a brilliant reader of the game - I know because we faced each other in New Zealand for years. And off the field, he's one of the few guys you can always have a beer with after the match."
So there you have it. Bachop is a great bloke - which in the long run is probably more important than being a great player.