At some stage in a cricketer's career, age, not opposition, becomes the greatest obstacle to success. As the grey hairs bloom one by one, time begins to erode the faculties that served batsmen in their youth; the reflexes, the power in their shoulders, the fleet of foot.
Bowlers often have their decline laid out unmistakably - even empirically. The lighter hauls correlate with less generous assessments on the speed gun, or a reduction in revolutions and turn. But batsmen, who are more tightly tethered to the vagaries of form, are less sure which is a temporary slump and which is a permanent one.
Many trade in panache for consistency, and stave away father time that way. Men who once commanded vast arsenals of punishing strokes smelt their techniques down until only a few well-chosen weapons of torment remain.
Last month, Tillakaratne Dilshan turned 36. It is strange to think of him as the oldest member of the Sri Lankan team because age seems to have forgotten him, or he it. In the Powerplays, he fields at backward point, where the sharpest earn their keep. In the middle overs, he ranges the deep, square of the wicket, where only the quick survive. At the death, he is found guarding the straight boundaries, where he recently made a stunning take, leaning over the ropes, clinching Sri Lanka victory where they would have had defeat if the ball had hit the ground. Where are the cushy positions at short fine leg or mid on for Dilshan? He is doing the work of young men.
His batting continues to be defined by its chutzpah. He had watched the new ball move off the seam appreciably from the non-striker's end, yet when he saw Kyle Mills pitch the ball in the corridor on the first delivery he faced, Dilshan sent it screaming through the covers, despite the away movement. It is the same cover drive he played when he first appeared for Sri Lanka, a whirr of arms, wrists and blade. The attitude, if anything, has grown bolder.
He continued to flash at the balls he fancied, and almost always, they resulted in fours. The dilscoop had gone out of his game for a while, triggering talk of ailing reflexes, but it has been restored the same as ever. He didn't play the one that flies over the keeper against New Zealand, but he scooped Jacob Oram square of short fine leg once. He had tried that shot twice already, but two failures were not enough to deter him, even for a stroke as high in risk as that.
But his batting is not without its own method. Even the freest spirits need some semblance of structure within which to knead their talent. Once the field goes out, the dasher in Dilshan gives way to the opportunist. The gaps are mined, often and exhaustively. Every chance to eke a second is grasped. He scored more runs in twos than any other batsman in the match, and that is not a statistic he is a stranger to.
Moreover, hittable balls almost invariably end up at the fence. The stream of runs into the outfield give the impression that Dilshan has wound down his aggression, but he snaps at the poor balls so readily and viciously, it is as if the wild Dilshan was always just lurking beneath that composed veneer, awaiting the first chance to let rip. Having not hit a boundary in nine overs, Dilshan spotted a rank full toss from Nathan McCullum in the 19th over and was down the pitch in an instant to blast it over extra cover. A few overs later, Trent Boult overpitched, and Dilshan bludgeoned it back at him so savagely, the bowler gave no thought to completing a return catch as he ducked in self preservation. As an opener, Dilshan has 13 hundreds to his 14 fifties. Conversion rates like that don't materialise without a formula.
He also has every shot in the playbook, so manoeuvring the field, as he did today alongside Angelo Mathews, should prove easier for him with the new rule allowing only four men on the fence. "It's much easier with the new rule, because the bowlers must bowl better than they used to," Dilshan said after the match. "Even if they make a small mistake, it's easy to score runs because there are only four men out. We planned to conserve our wickets at the start so that we could score quickly later. If a batsman gets into a good position, it's easy to exploit the new rule."
In the 30th over, Sri Lanka only had 13 to get to win the match, but Dilshan needed ten more for a hundred. In two balls, he smote a four over cover and a six over square leg to get to triple figures. Later, he was asked whether pulling that delivery onto the bank was an unnecessary risk in pursuit of a personal milestone.
"Why shouldn't I play the pull?" was his response. "It's my favourite shot and I have made a lot of runs with it. I don't think it's a risk for me."
In almost every way, Dilshan's lustre remains undimmed by experience. He is as free, confident and warlike as he has always been. In a dressing room and a batting order where even the youngsters tend to be thoughtful and measured, the fire in Dilshan's bones is refreshing.