India's left-right bowling quandary
In the eighth over of Sri Lanka's innings on Friday, Virat Kohli brought R Ashwin into the attack. He replaced Mohammed Shami, who had given away 22 runs in his first three overs. At the other end, Bhuvneshwar Kumar had been much less expensive, conceding just seven runs in four overs.
A bit of post-match number-crunching reveals that the situation shouldn't have come as a surprise. Kusal Perera and Lahiru Thirimanne, Sri Lanka's openers, are both left-handed, and Shami has a poor record against left-handers, averaging 55.00 and conceding 6.43 runs per over. It was no surprise, either, that Bhuvneshwar had kept them so quiet. He has an economy rate of 4.30 against left-handers, and an average of 26.12.
The numbers of India's new-ball bowlers against right-handers, meanwhile, tell a very different story. Shami has an average of 21.02 and an economy rate of 5.48, which is expensive but still better, by nearly a run every over, than the corresponding figure against left-handers. Bhuvneshwar, against right-handers, averages 46.42 and gives away exactly five runs an over.
There was good reason also for Ashwin to come on in Shami's place. He has an average of 26.45 and an economy rate of 4.65 against left-handers. Against right-handers, he averages 39.70 and concedes 5.09 runs per over.
Ashwin was hit for a six in his first over and briefly taken off the attack, but settled into a good rhythm and trapped Thirimanne lbw with a ball that skidded in from around the wicket. At the 20-over mark, Sri Lanka were 93 for 1. Ashwin had bowled six overs and conceded 25 runs. He - and India's attack - had only bowled to left-handers so far, with Kumar Sangakkara having come in at No. 3.
It was here that Ravindra Jadeja came on. Kohli might have waited this long because Jadeja hasn't tasted too much success against left-handers, averaging 58.43 and giving away 5.50 runs an over. India have also been reluctant to use him against left-handers. They have only faced 21% of all the balls he has bowled in ODIs. It's likely that other left-arm spinners around the world bowl a similarly small percentage of their overs to left-handed batsmen.
Ashwin, however, bowls 65.40% of his deliveries to right-handers; he can't escape it, since there are so many of them. His break-up between right- and left-handed batsmen is similar to those of Shami (roughly 63-37) and Bhuvneshwar (65-35). Their numbers seem to correspond far better than Jadeja's to what must be the distribution of right- and left-handed batsmen in international cricket.
Back to the match. Jadeja gave away 12 runs in his first two overs, before he was taken off for Ambati Rayudu, an off-spinner, in the 25th over. He came back three overs later, as soon as Ashwin had spun one viciously to have Perera caught behind. The reason for Jadeja's reintroduction wasn't too difficult to fathom: Mahela Jayawardene, a right-hander, had just walked in. Against them, Jadeja averages 28.84 and goes for 4.51 runs an over.
Real life doesn't rigidly conform to statistics, of course. Jadeja nearly had Sangakkara in the second over of his new spell, only for Dinesh Karthik to fluff up an easy stumping. In Jadeja's next over, though, things got back to normal. An exaggerated sort of normal. Jayawardene scooped him straight to extra cover and Chandimal, next ball, was bowled by a ripper that pitched middle and hit off. Two balls, two right-handers, two wickets.
Sri Lanka took the batting Powerplay in the 36th over, bowled by Jadeja. For the next over, with a right-left pair at the crease, Kohli could have brought on either of his two seamers, and each of them had four overs left to bowl. He chose Shami. Second ball, he jagged one back to trap the right-handed Mathews in front. In his next over, Sachithra Senanayake, another right-hander, popped him straight to midwicket.
Jadeja and Ashwin finished their 10-over quotas by the end of the 45th over. Their numbers told a tale that was in line with the story of their careers. Against Sri Lanka's right-handers, Jadeja gave away six runs in 26 balls and took two wickets. He bowled 34 balls to their left-handers, conceded 26 runs, and took the wicket of Chathuranga de Silva.
Ashwin, for once, was bowling to a team with a large number of left-handed batsmen in its top-order, and India could therefore use him the way they normally use Jadeja. Ashwin bowled 59 of his 60 balls to left-handers, taking two wickets and conceding 43 runs.
Sri Lankan teams, historically, have contained a lot of left-handed batsmen, and it's no surprise Ashwin has an excellent record against them - 26 wickets at an average of 25.73, and an economy rate of 4.52. Jadeja, as you would expect, hasn't done quite as well in terms of taking wickets, his 23 strikes coming at an average of 38.60, even if his economy rate is a more than decent 4.74.
With five overs left, Bhuvneshwar and Shami took over. By now, neither could do anything to stop a rampant Sangakkara, particularly with dew hampering their control. They bowled nine full-tosses in the last five overs, and Sangakkara's hundred took Sri Lanka home by two wickets.
Despite the hammering Sangakkara dished out to him - 26 runs off 12 balls - Bhuvneshwar finished his spell with reasonable figures of 0 for 45 in 9.2 overs. Again, India had the option of using him solely against left-handers if they wished, and they did so. Bhuvneshwar didn't deliver a single ball to a right-hander.
Shami, meanwhile, bowled 10 balls to right-handed batsmen, went for 16 runs, and took two wickets. He bowled 50 balls to left-handers, conceded 66 runs, and took one wicket off a full-toss. His display against Sri Lanka was a microcosm of his career, and so were those of the other three frontline bowlers. Any team planning for a match against India would do well to shuffle their batting order to exploit this quirk in their attack.
Karthik Krishnaswamy is a senior sub-editor at ESPNcricinfo