As an attack, man for man, it was clear India were outmatched in this series the moment it was announced that Ishant Sharma would not be making the trip. By the time Mohammed Shami was also injured, the contest between the two bowling attacks became one-sided.

After that, there was no way India could match Australia blow for blow playing traditional Test cricket. They were up against one of the greatest attacks when it comes to that.

And traditional Test cricket is predominantly an off-side sport - especially in Australia, New Zealand, England and South Africa. The bounce is true and the pitches are quick, so it is easy to score on the leg side off deliveries even ending up at off and middle. Fast bowlers spend time delivering tens of balls outside off, threatening the outside edge with catching men in slips and gully and dragging the batsmen across, before trying the change-up for the lbw.

In this series, India have subverted the tradition by not just bowling straighter but also keeping in place tight leg-side fields. The leg slip or leg gully has accounted for at least one dismissal of each of the key Australia batsmen: Steven Smith, Marnus Labuschagne and Tim Paine. Smith has clipped to backward short leg and been bowled around his legs once each; Labuschagne has flicked straight to leg gully on one occasion; and Paine has been caught at leg slip off R Ashwin once.

The wickets don't come just like that. There has to be persistent bowling at the stumps for that to happen. In this series, 45.5% of deliveries bowled to Australia's right-hand batsmen have been played on the leg side. And this number excludes the wicket-taking lbw and the bowled deliveries, and also the leaves down the leg side. On the other hand, only 31.8% of the balls have been played into the off side.

Contrast this to how Australia have bowled: 33.1% balls bowled to India's right-hand batsmen played into the leg side, and 36% into the off side. In the Ashes in 2019, for example, Australia faced a similar line of attack: their right-hand batsmen played 32.7% of the balls bowled to them into the leg side and 35% into the off side. Balls they played into the leg side in the Ashes were likelier to be errors by the bowlers, as they scored 5.41 an over off them and averaged 81.1.

During the current series, though, balls played into the leg side have yielded only 2.65 an over for a wicket every 21.5 runs. Even India, on their last trip to Australia, played more traditional cricket: 33.9% of the balls Australia's right-hand batsmen played went into the leg side for 4.93 an over and 49.5 per wicket; 41.9% went into the off side.

Batting against this Indian attack, Australia have had significantly fewer opportunities to leave the ball while playing at them has brought them hardly any runs. The moment Australia look to score off these straight deliveries, mostly defensively, they bring the leg trap into play. Depending on the bowler, there is a leg gully, a short leg, one or two short midwickets, a mid-on or a long-on and one or two boundary riders square on the leg side.

The plan marries with the theory that if you deny Australia quick runs and boundaries, they are not good at patiently batting time and waiting for less potent spells. This has been their slowest series this century. These fields with the freedom to bowl straight has given India a bigger margin of error while possibly bringing in more modes of dismissal into the picture.

"They've certainly come in with a plan, making sure that they're really not leaving stamps and having a really heavy leg-side field," Labuschagne acknowledged. "It obviously slows the scoring rate down because you know those shots that you do get on your legs go for one or four. And then they're always keeping those catchers in the game. We also need to come up with ways to put them under pressure."

This has resulted in interesting overall numbers in the series. Both sides have scored nearly the same number of runs - Australia's 679 against India's 676 - for the loss of same number of wickets - 32 - but Australia have had to face more balls for it and they have been more in control than India: 86% to 83.1%. According to ESPNCricinfo's control metric, Australia's batsmen have been in control more often and not in control less often than India and yet both sides have lost the same number of wickets for almost the same number of runs. In other words, India have had such field sets that they have cashed in more on Australia's indecision.

This is nothing less than a heist: flipping the geometry of the game, turning a traditionally negative form of operation into an attack and out-thinking the home team. However, it can be argued India didn't have a choice. They had a raw attack outside Jasprit Bumrah and Ashwin. They couldn't be expected to compete with channel bowling for long periods. As bowlers from India historically have been, they would have been - Umesh Yadav still is - prone to bowling too straight and get picked off. Instead of asking them to play a different game, India protected their weakness and with discipline and some fortune, turned it into a strength.

Against a well-oiled brute of a bowling unit, India have indulged in non-traditional warfare. It sounds great on paper to say that the more you make them play the ball while denying them opportunities to score, the more the chances of taking a wicket; but to execute it is quite another achievement. The bowling still has to be precise and relentless. Also it is not clear if this was a discussed plan in team meetings or if it is a case of individual bowlers - Bumrah and Ashwin are clever enough to do so - coming with their own plans and the others going with the flow.

The efforts of Bumrah and Ashwin have been immense. This is why Ajinkya Rahane went to Ashwin before using Mohammed Siraj on the first morning during the second Test in Melbourne. India had tied Australia down with a plan that relied entirely on control; they didn't want to risk losing it bowling a debutant early on. Ashwin used the moisture in the pitch expertly and laid the foundation for the leg trap to continue.

Between them, Ashwin and Bumrah have bowled 156.1 overs of the 268.5 that India have been in the field for. They have conceded just 366 runs for 18 wickets between them.

Heist while it might be, the thing with heists is they are not repeatable so easily. In the longer run and over a four-Test series, you would expect a bowling unit drawing the larger amount of indecision from the batsmen to prevail. If India have out-thought them so far, expect Australia to put their best brains at work to try to counter this line of attack. It will be fascinating to see if India continue with the leg trap and how Australia respond in the coming two Tests.

Sidharth Monga is an assistant editor at ESPNcricinfo