Bazball. Since it entered cricket's lexicon, no word has divided the sport like it. No two people can even seem to agree on what it means, but it's actually not that hard to figure out if you've followed England since Brendon McCullum took over as their Test coach.
They seem to have recognised that English cricket is producing a lot of skilled attacking batters and not too many traditional Test-match players, and decided to make the most of the situation. They've backed attacking young batters like Ben Duckett, Zak Crawley, Ollie Pope and Harry Brook, and attacking older heads like Jonny Bairstow and Ben Stokes, and backed them to bat in their natural style: to recognise what their best modes of attack are, practice them assiduously, and play those shots with freedom, knowing that low scores will not put their spots under threat. Playing this way, England have made the trade-off between a higher scoring rate and shorter innings, reasoning that when it works well, it gives their bowlers more time to take 20 wickets in a Test match.
This is Bazball - or at least a core element of it. It's a simple concept, and it remains that, if we ignore the many-headed chameleon that it has become in the wider discourse. Like every other cricketing concept, it comes with pros and cons, and like every other cricketing philosophy that Test-match teams have embraced, it deserves taking seriously, whether it happens to be producing wins or losses at that given moment.
India have certainly taken Bazball seriously. If they're one of the great Test teams, it's not just because they're blessed with some of the best batters, fast bowlers and spinners in the world. It's also because they are adaptable. They respect their opposition, and work hard to find ways to beat them. Here's how they came from behind to beat Bazball 4-1.
Traditional Indian pitches, not square turners
Last year, when India played three successive Tests against Australia on pitches where the ball turned sharply from day one, their coach Rahul Dravid pointed to a global trend for bowler-friendly pitches born of the need to secure as many World Test Championship points as possible.
"Every team is getting results at home or are putting in really good performances at home, so there is a premium on results," Dravid said. "You get four points for a draw and you get 12 for a win, so there is a premium on that, there's no question about it."
The WTC points structure hasn't changed in this cycle, and Dravid remains India's coach, but India moved away from square turners in this series against England. Why? Well, because Bazball.
When this series began, it was clear that India had by far the better bowling attack for Indian conditions, and that England, who arrived with four spinners of whom three had one previous Test cap between them, had a particularly weak attack even by the standards of recent visiting teams.
It was also clear that India, having moved on from Cheteshwar Pujara and Ajinkya Rahane and missing Virat Kohli, who was absent for personal reasons, would start the series with the less experienced batting line-up of the two sides. Just for that, it made sense for them to prepare pitches that protected their batters a little while allowing the superior skills and experience of their bowlers to come through.
But the nature of Bazball must have also come into it. Batters taking frequent risks can end up defying the odds and make sizeable scores in all kinds of conditions. But it's likelier for one or two chancy, attacking innings to make a difference to the result of a shorter contest on a raging turner than a longer contest on a flat pitch. This was the thinking behind India giving Suryakumar Yadav a Test debut against Australia last year.
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With England's line-up packed with Suryakumars, India made the choice to lengthen the contest and ask the opposition to take risks for longer, against the superior attack.
It wasn't entirely a coincidence, then, that England's one win, and their closest defeat, came on the two most challenging batting pitches of the series, in Hyderabad and Ranchi.
Stop the singles
Pitch preparation isn't an exact science, of course. A flat pitch - at least relative to those from the Australia series last year - can deteriorate and turn a fourth-innings chase extremely tricky, even against an inexperienced spin attack. And a chancy innings can last a long, long time: Pope survived 72 false shots while scoring his match-turning third-innings 196 in Hyderabad. England's win in Hyderabad was, in many ways, a freak result.
But there were still learnings for India to imbibe. As good as their spinners are, they were still bowling to a Bazball line-up for the first time, still figuring out the best way to react to a batter reverse-sweeping as often, and as skilfully, as Pope did in Hyderabad.
R Ashwin, Ravindra Jadeja and Axar Patel could probably have done two things differently against Pope. They could, for one, have been stubborn with their length rather than reactive - they gave away a few risk-free scoring shots while attempting to go fuller and hunt for lbws. And they could have been less reactive with their fields.
One of the key stats from Hyderabad was the percentage of runs scored in singles, with England (36.61) doing slightly better than India (35.99) on that measure.
This changed dramatically in Visakhapatnam and Rajkot. England seemed to temper their batting approach thereafter, but India continued to win the singles battle even in Ranchi and Dharamsala. It allowed their bowlers to keep batters on strike for longer, and build up a better rhythm and keep creating chances.
Keep adjusting your plans
India's willingness to give away boundaries in the effort to protect singles was evident in the first innings in Rajkot. On day two, after Ben Duckett had torn into India's bowling with an audacious century, Ashwin spoke of the bowlers judging themselves purely on their processes.
"[…] I wouldn't be too flustered because they haven't been able to hit me to different parts [of the ground], which is what will [worry me]," Ashwin said. "I am clear on picking where they have to take a risk, such that I'm still bowling my best balls."
Ashwin and Kuldeep Yadav, who both turn their stock ball away from the left-hand batter, spent long periods bowling without a deep midwicket even when Duckett was slog-sweeping them frequently.
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This changed on the morning of day three, when Kuldeep went into a more defensive mode, bowling a wider line to Duckett with deep midwicket out. He was reducing his chances of getting Duckett bowled or lbw, but was asking the batter to play differently: either avoid the slog-sweep, or take a greater risk to play it, fetching it from outside off stump, against the turn, with a fielder in place for the mishit.
The plan worked - not so much in how Duckett eventually fell, but in controlling his scoring and allowing Kuldeep to build a mesmerising rhythm through a match-altering 12-over spell. The wide line challenging the slog-sweep also worked on the first morning in Dharamsala, where Kuldeep found his top edge to give India their first breakthrough.
This was just one example of how India's bowlers grew through the series, and gradually got on top of Bazball. England's spinners had a better collective average for the series than their India counterparts after the second Test, but India's quality came through in the end. And how. By the end of the series, India's spinners had taken 69 wickets between them at 24.86, and England's 60 at 39.16.
Five bowlers, always
It's been written about before, but it's worth mentioning once again: India stuck resolutely to a five-bowler strategy, and picked their best five bowlers even when they had the chance to hedge their bets with an extra allrounder. It helped them, of course, that so many of their spinners are genuine allrounders in home conditions, and that the least talented batter among their spinners, Kuldeep, has turned himself into an admirably stodgy lower-order contributor.
Even so, despite the inexperience running through their top order, they took a brave call to keep playing their best five available bowlers, and the results were clear to see.
There were times during the series - particularly the second innings in Rajkot and Ranchi, and both innings in Dharamsala - where England collapsed while appearing to bat in neither a Bazball way nor a non-Bazball way. It wasn't because they had lost their skills or their ability to plan; it was the result of the sustained pressure they were under from India's bowlers, with no weak link to act as a pressure valve.
Don't copy the Bazballers (or copy them better)
In the first two Tests, India's batters frequently gave the impression that they were leaving scoreable runs unscored. This was exemplified on day two in Hyderabad, when a string of their batters fell to attacking shots off the spinners, with none of their top five falling to the traditional modes of dismissal: bowled, lbw, caught by keeper, slips or bat-pad.
According to ESPNcricinfo's data, nearly 56% of the wickets England's bowlers took in Hyderabad came off aggressive shots from India's batters. England's batters only lost 25% of their wickets to aggressive shots.
This changed in time, with India forcing bowlers to "earn" more of their wickets as the series progressed - double quotes because big shots aren't always unforced errors - and England being forced more and more into taking seemingly unreasonable risks.
You could read this two ways. England's methods, you could say, drew India into trying to out-Bazball them, before they learned their lessons and began to trust their own ways. Or you could say that India learned, over the course of the series, to shut down Bazball - block their batters' favoured scoring routes, and force them to into taking, so to speak, riskier risks - while at the same time unveiling their own version of Bazball - refining their risk-taking, taking sounder, timelier risks. They did, after all, hit 72 sixes to England's 30.
Perhaps it was true, after all. Bazball had taught India how to win.