He's taken 17 wickets at the unearthly average of 13.64, and he's conceded just 2.87 runs per over in a series where the second-most-economical India bowler has gone at 3.91. It's fair to say Jasprit Bumrah has been the most influential player on either side so far, and the biggest reason for India going into the fourth Test in Ranchi with a 2-1 lead. He'll play no part in this game, however, and that leaves India with a thorny selection problem. Do they go like-for-like and replace him with a fast bowler? Do they pick a spinner instead? Here are the questions that'll worry them in the lead-up to the match.
How will the pitch play?
Two days out from the Test match, there was a dry, cracked look to the pitch at the JSCA Stadium. The England batter Ollie Pope described it as "platey", and noted that one half of the pitch - if you divided it longitudinally - was significantly more cracked than the other.
"At the minute, it looks like batting from the far end, [the cracks are] outside the right-hander's off stump and then from this end, the left-hander's off-stump. At the minute, it just looks like it's down the wicket, it's kind of plated on one side and then the other side looks like a pretty good wicket."
Ranchi has, in the past, thrown up deceptive-looking Test pitches. The one for its inaugural Test, during the India-Australia series in 2016-17, wore a dark, almost blackish look on the eve of the game, but this was down to the watering the black soil had undergone. The pitch proved to be the slowest and flattest of the series, and Australia saved a high-scoring Test on the last day.
The other Test here, during South Africa's 2019-20 visit, also produced plenty of first-innings runs - at least for India. They batted first, declared on 497 for 9, and proceeded to bowl South Africa out for 162 and 133, with fast bowlers Mohammed Shami and Umesh Yadav taking 10 wickets between them.
The look of the pitch for this India-England game, though, suggests the spinners could come into the picture a lot more - and a lot earlier - than they did in those two Tests. There's a chance that India may even have requested this - the first three Tests were played on pitches that were, to varying degrees, flat to begin with - in the knowledge that Bumrah would be resting.
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So should India play an extra spinner?
England seem to be considering a return to their bowling balance of the first two Tests, where they played just the one fast bowler and four spinners including Joe Root. India could do likewise too, and replace Bumrah with Axar Patel, who played the first two Tests before sitting out the third one.
The appeal of this is two-fold. Axar's fast, stump-to-stump left-arm spin could be extremely useful on a track that turns early, and his presence would lengthen India's batting too.
There is, however, a chance that four spinners may end up being one too many even on a turning track. It makes plenty of sense to play four fast bowlers on a seaming pitch, because fast bowlers tend to operate best in short bursts, and do well with constant rest and rotation. Spinners, on the other hand, come into their own over long spells. Last year, Axar played all four Tests of India's home series against Australia, but bowled far fewer overs than R Ashwin and Ravindra Jadeja, and ended up as something of a batting allrounder who happened to bat at No. 8 or 9.
This issue was exacerbated by the fact that the first three Tests of that series were played on sharp turners, and each of them only lasted three days. The shorter Australia's innings lasted, the less room there was for India to bowl their third spinner.
Given all this, four spinners could be overkill in Ranchi, especially if there's sharp and early turn available.
Two seamers then? And which second seamer?
Given that they have three world-class spinners, it seems likely that India will stick to the two-seamer formula to try and cover every eventuality. Reverse-swing has played a significant role in the series so far, and both Bumrah and Mohammed Siraj have shown how penetrative they can be with the old ball. There's even the chance of a bit of new-ball swing, even though there hasn't been much of it in the series just yet. Ranchi is expected to have the coolest conditions of the first four Tests, with maximum temperatures only in the 25-26-degree Celsius range, and clouds and a small chance of rain forecast for Sunday and Monday.
Who partners Siraj in the seam attack then? The two options in India's squad are Mukesh Kumar, who played in Visakhapatnam and has three Test caps, and Akash Deep, who is yet to make his Test debut.
Mukesh is known for his accuracy and his ability to deliver an upright seam and extract whatever help there is in the surface - he's got a bit of Shami in him, though he doesn't have his pace. Akash is quicker, and hits the pitch harder - this certainly seemed the case in the nets two days out from the Test match, where Rohit Sharma adopted an early trigger against Akash, shuffling across to off stump before release, while he mixed things up against Mukesh, triggering sometimes and standing still at other times.
Mukesh took some tap from England's top order in Visakhapatnam - he ended up with an economy rate of 5.83 across the two innings - but didn't necessarily bowl badly; all of India's bowlers bar Bumrah have gone for plenty at various points during the series. Mukesh was initially part of India's squad in Rajkot, but was released so he could play for Bengal in their Ranji Trophy match against Bihar. He took a ten-wicket match haul in that game, but that pitch at the Eden Gardens was grassy and entirely unlike the one India will play on in Ranchi.
Akash, meanwhile, got called up to India's squad ahead of the Rajkot Test, on the basis of his form for India A, for whom he recently took 11 wickets in two unofficial Tests at an average of 16.95.
Both Mukesh and Akash bowled long spells in the nets on Wednesday, and going by precedent it would seem Mukesh is likely to come back into the XI in Bumrah's place unless India think they need Akash's extra pace.
Is there a way to play both Axar and a second seamer?
There is a way for India to play two seamers and four spinners if they play Axar or Washington Sundar as a batting allrounder and leave out Rajat Patidar, who batted at No. 4 in Rajkot and made 5 and 0.
Both Axar and Washington are capable of doing a job in the top six, but it's unlikely India would play either ahead of a specialist batter given that they already have three spinners. Patidar endured a difficult Test in Rajkot, but it's hard to judge a batter's form on the basis of two single-digit scores, particularly when he was out in unusual ways in both innings. In the first, he got a ball that turned unexpectedly and stopped on him, and popped a leading edge to cover. In the second, he pulled a long-hop straight to short midwicket. India will also remember how assured he looked while making 32 in his first Test innings in Visakhapatnam.
In general, India don't drop players on the back of one bad Test, and tend to give players a run in the side if they're able to. With KL Rahul unavailable, there is probably no immediate threat to Patidar's spot.