Global cricket tournaments have a way of shaping teams' priorities. At the 2017 Champions Trophy, India realised they simply weren't picking up enough middle-overs wickets. After the tournament, they swapped the fingerspin of Ravindra Jadeja and R Ashwin for the wristspin of Kuldeep Yadav and Yuzvendra Chahal. By the time the 2019 World Cup rolled round, Kuldeep and Chahal had more or less solved India's middle-overs issue, but in doing so had become part of a new problem: they lacked the batting ability of Jadeja and Ashwin, and India now had a long tail that forced the top order to bat more conservatively.
It was a trade-off India were initially willing to make, and they picked both Kuldeep and Chahal in their first seven matches of the World Cup.
But that seventh match, against England, told India that the ploy was cramping their batting approach to an unmanageable degree. Kuldeep and Chahal went for a combined 1 for 160 from their 20 overs. More damagingly, India were so mindful of their lack of depth that they adopted a safety-first approach in a chase of 338, and towards the end chose to play for net run-rate rather than have a proper crack at the target.
India's frontline bowlers in that match, apart from the two spinners, were Mohammed Shami and Jasprit Bumrah - four No. 11s, or No. 10s at best. As good as each of them might be with the ball, India decided they could no longer play all of them together.
India have played 12 ODIs since then, and they have picked only one wristspinner - usually Kuldeep - in each of them. Jadeja went to the World Cup as a back-up option and ended it with one of the most heroic ODI performances in a losing cause, in the semi-final against New Zealand; he's now become an integral part of the team once again, featuring in each of India's last 11 ODIs.
India's recognition of batting depth as a non-negotiable has also coincided with the start of their preparations for the T20 World Cup, to be held in Australia later this year. Soon after the World Cup, India rested both Kuldeep and Chahal from their T20I squad, and turned instead to spin-bowling allrounders: Jadeja, Washington Sundar and Krunal Pandya. The two wristspinners have since returned - with Chahal getting the bulk of the games - but the emphasis on batting depth hasn't gone away.
The thinking is clear. With more depth, India want to free their batsmen up to take more risks. It's how most of the best T20 line-ups bat, but it's an approach India have resisted for a number of years, partly because they haven't always had the personnel to pull it off. They're trying it now, with mixed results -there has been resounding success, as in Mumbai against West Indies, and there have been times where it's gone horribly wrong, as in Bengaluru against South Africa - and they will keep trying it over the coming months.
"Will Jadeja play as the lone spinner, ahead of the wristspin options, if India play an extra fast bowler? It's hard to say, but he's made himself just as hard to leave out."
For most of this time, Hardik Pandya has been out of the side, undergoing and then recovering from back surgery, leaving India to force-fit other allrounders into his No. 7 role, in both ODIs and T20Is. Jadeja has usually been that man. Out of nowhere, he's become one of India's most important white-ball cricketers.
The new Jadeja isn't too far off the old one: a match-winner on slow, grippy surfaces (as he showed in the second T20I in Auckland) with the defensive skills and smarts to bowl economically on flatter pitches; a gun fielder; and a lower-order batsman who does a useful job in an area where India lack other options.
In Test cricket, Jadeja's batting has undergone a transformation so radical that he's now a legitimate No. 6 in Indian conditions. In the shorter formats, he doesn't quite have the power or range of others who play his role, such as Colin de Grandhomme, Andre Russell, or indeed Pandya.
Consider these numbers. Of the 13 batsmen to have scored at least 100 ODI runs at No. 7 since the start of 2019, Jadeja has the fourth-worst strike rate, and only one six in 132 balls. In the same period, of the 36 batsmen (all positions) with at least 50 runs in the last five overs of ODI innings, Jadeja has the third-worst strike rate.
But India won't judge Jadeja's output based on those numbers. They'll note that he's contributed almost every time he's been asked to bat in ODIs (he's hardly been required to in T20Is), following up his incredible 59-ball 77 in the World Cup semi-final by scoring 121 runs off 116 balls in his next six innings, with four not-outs in the mix. They will note that he joined Virat Kohli at 228 for 5 against West Indies in Cuttack, with 88 needed off 67 balls, and scored an unbeaten 39 off 31, finishing the job in Shardul Thakur's company.
His bowling, meanwhile, has been routinely excellent. Since his return to the side in India's last league game of the World Cup, he has been their second-most-economical regular bowler, behind Bumrah, and if his average of 40.90 doesn't look too flash, it's still significantly better than those of Kuldeep (46.60) and Chahal (47.50).
In T20Is, he's been India's most economical bowler since the end of the ODI World Cup, his economy rate of 6.34 putting to shade that of Chahal, who's gone at 8.83 in the same number of games (eight). It must be remembered, though, that Jadeja hasn't bowled in the Powerplay at all in this period, and only three overs at the death (16-20), while Chahal has bowled three overs in the Powerplay and seven at the death.
Given all this, this is the question that remains to be asked: what happens when Pandya returns?
If India play two spinners, Jadeja is certain to keep his place in the ODI side, at No. 8, and will likely contest the same role in T20Is with Washington, depending on the number of right- and left-handers in the opposition line-up.
But will Jadeja play as the lone spinner, ahead of the wristspin options, if India play an extra fast bowler? It's hard to say, but he's made himself just as hard to leave out.