It has been the summer of the six: 1257 of them, to be exact, comfortably a record in the T20 Blast. The average run rate has soared from 8.30 to 8.61 and, there have been 27 scores of 200 or more, up from a previous high of 20 with finals day still to come. These are the raw numbers underpinning the T20 batting revolution.

These statistics have been underpinned by the T20 schedule being reformed to become more conducive to six-hitting. Compared to previous summers "the pitches were so much better" this year, believes Somerset's T20 captain Jim Allenby. The block format has led to pitches, tailor-made for T20 cricket, in lieu of wickets that have previously been used for a Championship game.

In the last three years, incongruously, the T20 Blast began in mid-May, the night before the FA Cup final, when fresher pitches made it harder to score freely; this year's competition didn't begin until July 7. The "warmer weather" aids big-hitting, believes Gary Wilson, who led Derbyshire to the quarter-finals.

But that is only part of the reason. The surge in scoring reflects a broader shift in T20 approach: how teams are redefining what scores are possible.

This season, Nottinghamshire have topped 180 eight times and 200 three times. They chased 184 against Durham with a ludicrous 37 balls to spare and, almost as absurdly, chased down 224 against Yorkshire with five balls and five wickets to spare.

"It felt attainable," says Peter Moores, Nottinghamshire's coach. "Go back a few years and if someone got 200 in T20 you'd just think you had absolutely no chance. Now, to score at 13 an over on the right surface has become possible because people can clear the ropes better. We talk a lot about the bats but the skill of the batters has gone up.

"More and more now batters are becoming very skilful at not just hitting the ball but opening up spaces and deflecting the ball into different areas, which makes it really hard for bowlers to decide where they're going to bowl."

Moores cites Samit Patel in the Blast quarter-final against Somerset, lofting a delivery over mid-on and then, when third man had been brought up to allow mid-on to drop back, deflecting the next ball through short third man for another boundary.

"It used to be that you got a little bit of leeway... I don't think that happens any more" Peter Moores, Nottinghamshire coach

Higher scores are also the product of broader tactical shifts in T20, with teams recognising the possibilities, and necessity, of scoring quicker. There is better "awareness of successful game plans," Allenby believes. "It's become obvious that you need to be aggressive the whole 20 overs."

Moores has noticed three particular tactical shifts during games.

First is attacking from the very first ball. "It used to be that you'd get a little bit of leeway - the first over might not be attacked, and you might get a couple of cheap overs in. I don't think that happens anymore. With someone like Alex Hales, if the first ball is in the place to hit he'll put it out of the ground."

In T20 history, the first over of an innings has been the most frugal, conceding just under six runs, but coaches are increasingly regarding cautious accumulation in the opening over as an inefficient use of resources. In the first two overs of the Blast, run rates have soared from 7.19 to 7.91 this summer. Sixes in the first two overs have become almost 50% more common, rising from 61 to 88 since 2016.

Secondly, Moores has observed how an old T20 trope - the notion that a batsman could hit one of the first two balls of the over for a boundary, and then bring up ten runs in the over through risk-free accumulation thereafter - has been torn up. "No longer are batters satisfied with getting an early boundary and then knocking it around for the rest of the over. Once they get an early boundary, they see that as an indicator to try and put a bowler under real pressure and go hunting for more boundaries in that over straight away."

Thirdly, the traditional post-Powerplay lull - after the first over, the seventh and eighth overs have been the two cheapest of the innings - is now regarded as a luxury that teams cannot afford. "We're aware that we want to keep the pressure on the opposition coming out of the Powerplay," Moores explains. "You don't want to take a breather in T20 because it's too short. If you take breathers in the game and another side don't then that could be the difference between winning and losing."

Across the seventh and eighth overs, the average run rate has risen from 6.97 to 7.59 this summer.

Most important of all is simply more skilful batting. "Players can hit 360 degrees more than ever now," observes Kent's skipper Sam Northeast. "You've got guys who have grown up with T20 and now you're seeing the rewards of that."

Wilson agrees, seeing the effervescence of young batsmen as a reflection of T20's growing importance in cricket's ecosystem from the professional game to the lower levels.

"More players are coming though now having grown up on a diet of short-form cricket and therefore back their skills to be able to hit it over the ropes. When T20 started and for the subsequent 10 or so years it was only those players playing at domestic level that had given it a go. Now, it's being played at every level and I think that is a big influence."

Players and coaches all agree that the block format has helped increase average scores - "We can enhance our skills a lot more in training now," Northeast reflects. Yet this invites the question of why should this benefit batsmen more than bowlers? After all, a block format allows both to hone their T20 skills.

"People recognise that they need to be able to at any given time be able to hit the ball out of the park." Tom Moody, tournament director of the Caribbean Premier League

The first answer is that the block allows all players who bat to harness their batting skills - not merely frontline batsmen. As such, teams are becoming far better-equipped to reach big scores if their leading batsmen fail; this knowledge, in turn, actually liberates top-order players to attack with more impunity.

"The more we play, people understand that if you've got good depth, even though you're being aggressive, you won't get bowled out," Moores explains, adding to the general notion among analysts that wickets have been overvalued in T20, artificially limiting total team scores. "Sides don't get bowled out very often in T20 cricket. Most sides have got batting down to eight or nine so it gives some freedom for the guys up top to go and play." As such, "rebuilding is still being very aggressive - you're still looking to go at tens often."

There is also a basic physiological reason why a block favours batsmen over bowlers. "The difference between batting and bowling is the physical nature of bowling which means you can't practise as much bowling, because of injury risk," Moores says. "The batters can practise striking a lot now whereas the bowler can only practise so much before you offer yourself up to risk of injury."

That's why the growth in scoring isn't really an English phenomenon at all: it can only be properly understood in the context of the direction of travel in T20 leagues the world over. Since 2012, the Indian Premier League run rate has increased by 0.59; the Caribbean Premier League run rate has increased by 1.51; the now defunct Ram Slam in South Africa by 0.60; and the Big Bash by 0.71.

The surge of run rates in this year's T20 Blast, which is believed to have quicker scoring than any league ever in a Test nation ever apart from the 2012 T20 tournament in New Zealand, mirrors what is happening throughout the T20 world.

Tom Moody, tournament director of the CPL, reckons the pool of players able to hit sixes reliably has "doubled" in the past ten years - so scores will continue to rise. "You've got guys down the order now that can bang it out of the ground too - because it's a practised still now. People recognise that they need to be able to at any given time be able to hit the ball out of the park."

As recently as the 1999 World Cup, he says, Lance Klusener was the only player "to actually specifically practise hitting sixes. So it wasn't just 'I'm having a net and I'm slogging a few', it was a specific drill that he was practising. Everyone does that now."

Few expect that shift to be undone as the bowlers find a way to respond. "I don't expect it to go back," Moores says. "Bowlers are starting to move, but batting has moved faster than bowling in T20." Whether bowlers can find a compelling riposte will determine whether scores stabilise - or cricket's great divergence grows greater still.