Hanging on too long and running the risk of your legacy being diluted is a dilemma facing Ponting.
Retirement dilemma facing Ricky Ponting
It may be glib to suggest Ricky Ponting should seek the advice of a batsman who has scored 25 fewer hundreds and 6,500 fewer Test runs than him, but when it comes to contemplating calling time on your international career, which Ponting is right now, few could have scripted it better than Nasser Hussain.
The former England captain bowed out after scoring a match-winning century against New Zealand in 2004. He knew it was beneficial for the team for his place to be taken by a younger and hungrier batsmen.
He was aware, at 36, there were going to be fewer better opportunities to bow out than having just hit the winning shot in a Test at Lord's with his favourite cover drive. Better to quit at the pinnacle of your career than be pushed after a run of low scores.
Prior to yesterday's unbeaten half-century Ponting averaged 25.44 in his previous 14 Tests. Today he has the chance to score a century, lead Australia to another victory and bow out on a high.
It would be a fitting finale for a player who only has Sachin Tendulkar and Rahul Dravid ahead of him in the Test run charts.
Should he play on he is in danger of seeing his average dip below 50 and his achievements as a prolific run-getter being diluted.
That would be a crying shame as nothing should detract from Ponting's match-saving 156 against England in 2005 at Old Trafford. Michael Vaughan said it was "one of best knocks I saw" while Derek Pringle, in The Daily Telegraph, hailed it as the "captain's innings of the 21st century".
He may not be captain anymore but he played like one yesterday.