It is the age-old dilemma in sport: when is the optimum time to retire?

The late world featherweight champion Willie Pep summed up the danger for boxers who hung on too long when he said: “First your legs go, then your reflexes go. Then your friends go.”
When rugby union was amateur, players had careers outside the game that needed cultivating.
To take three outside-halves: Richard Sharp retired at the age of 26, although he made a short-lived comeback, Barry John was a year older when he tired of the fame game and Phil Bennett played his final match for Wales when he was 29.

Why not play on...