If there has been an abiding criticism of England in recent years, it is that they have become, in effect, green-track bullies.

There has been some truth in the criticism, too. They arrived in Sri Lanka having not won any of their previous 13 away Tests, after all, and without an overseas series win in almost three years. They were dangerous in England, certainly, but without the Duke's ball and seam and swing-friendly conditions, their bowling attack could look toothless. Over the last couple of British winters, they have conceded 600 totals on four occasions: twice each in India and Australia. Over the same two seasons in England, they have conceded 400 only once.

Sri Lanka knew all that. And they knew that England's spin record - both delivering it and playing it - was modest. So they attempted to produce pitches that would exploit England's enduring weakness and encourage their own strengths.

To some extent they were successful, too. Only one wicket in the entire Kandy Test fell to seam bowling and 38 fell to spin. England's seamers have, to date, taken just three wickets in the series. In normal circumstances, you would expect figures like that to bode ill for England.

Yet here they are two-up with one to play. So well have they adapted to the challenge in front of them that they have their first series win in Asia since 2012 and their first in Sri Lanka since 2001.

While Sri Lanka are clearly not the side they once were - how could they be after the retirements of Rangana Herath, Kumar Sangakkara and Mahela Jayawardene in recent times - the fact is they have defeated South Africa and Australia here over the last couple of years. They have won in Bangladesh and the UAE, too. This is, therefore, a significant victory.

The key to England's success is the options and depth their allrounders provide. To have two men in the top six (Ben Stokes and Moeen Ali) who have centuries and five-wicket hauls at Test level is an incredible asset for any captain. When you also throw in Sam Curran, whose first-innings 64 was vital, and Adil Rashid, who is averaging 22 from No. 9 in this series, you end up with a batting line-up that is both tough to finish off and can exploit a softening ball and weary bowlers. The combined value of England's two tenth-wicket stands in this Test was 101. You don't have to be a mathematician to understand the significance in a match where the margin was 57 runs.

More than that, though, the all-round strength allows England selection options they could not afford if they were forced to pick a side containing six specialist batsmen, a keeper and four bowlers. While a few non-Asian sides might have played three spinners here, not many have also managed to field three seamers. In theory, at least, just about every base is covered.

That has been particularly true when picking the spin attack. In isolation, all three of England's spinners have flaws. Rashid bowls too many four-balls; Moeen does not quite have the control to build pressure and Jack Leach can look just a little pedestrian.

But in combination, it is their strengths that are highlighted. So Leach adds control and troubles right-handers, in particular. Moeen adds bite and troubles left-handers, especially. And Rashid, who has it in him to bowl wicket-taking balls on flat surfaces when the batsmen are on top, is the partnership breaker. When Root is able to combine all three of them - and throw in a few overs himself when required - he has a potent weapon.

"The three of them complement each other beautifully," Root said afterwards. "Jack gives a lot of control and the fact that they all spin the ball differently does help. It brings a lot of variations and gives the batters something to think about all the time."

The key difference, however, has been Leach. His control has allowed England to build pressure in a way that was noticeably absent in Australia and India. Maybe Moeen's batting will retain his position as first choice when they return to England but Leach has quickly emerged as the most reliable of the trio and the man to whom Root turns most often. He has bowled more overs than either of them in this series.

"When pressure is building at the other end with the likes of Jack bowling, it allows Moeen and Adil to be really aggressive and try to take important wickets. The impact Jack has had - the way he's performed on these surfaces and shouldered the pressure despite not having a huge amount of experience - has been brilliant."

Somerset deserve a mention here. Some of the surfaces they have provided over recent years at Taunton have provided substantial assistance to Leach and co; a fact that has left some opponents deeply unimpressed. But bowling in those conditions appears to have developed Leach's experience and confidence. And if that has helped England win in Asia,

"Jack has taken all the experience that he's had at Somerset bowling on those wickets at Ciderabad, or whatever they call it down there, and he's done a fantastic job," Root said.

They are not especially easy to captain, though. All three are more likely to deliver far more four-balls than the likes of John Emburey or Ray Illingworth might have done in the past. As a result, Root is obliged to stick with in-out fields that can allow batsmen to pick off relatively easy singles. But, such is the pace - and the mentality - of the modern game that batsmen rarely seem content with such slim pickings. Still, Root deserves credit for keeping his side calm and focused in the field despite periods of play - not least on the fourth afternoon - when Sri Lanka looked capable of winning. Someone does need to have a quiet word with him about his bowling, though. To have bowled after lunch yesterday was madness; no wonder he admitted to a sleepless night and doubts over not asking Stokes to bowl.

It might be simplistic to credit just Root here, anyway. When we reflect on this period in a few years, it may well be we conclude that the 2015 World Cup was the turning point in England's fortunes. Having been humiliated in it, England - encouraged by Eoin Morgan, in particular and the inspirational example of Brendon McCullum - identified new players and a new way of playing that suited them which has been encouraged by a laid-back coaching team who emphasise enjoyment and skills more than discipline and restraint. It has clearly fed into the way in which they play their Test cricket

"We are learning from the one-day side," Root said. "Eoin said to the guys 'go and play with freedom' and you saw them embrace that. We saw a big improvement very quickly.

"We are learning from the one-day side. Eoin said to the guys 'go and play with freedom' and you saw them embrace that. We saw a big improvement very quickly"

"It's not quite as straightforward in Test cricket. You can't just say 'swing as hard as you can' but at times being able to take pressure off each other and have a good understanding of how you want to play in certain circumstances, can really help you. Sometimes you'll make the wrong decision but get away with it because you've really thrown yourself into it.

"In this part of the world, on surfaces which spin dramatically, it can be very difficult to trust your defence. The conditions have been extreme. So we've got to play to our advantage as much as we can. We saw that as an opportunity to play in that [aggressive] manner in these conditions.

"It can be difficult to stay true to that. In one-day cricket things are all laid out for you; if you're batting second for example. And the wickets are generally pretty good. In Test cricket, you have to be more adaptable. So we're learning. But you are starting to see the confidence grow and an improvement within the squad. This is a very special win."

There are other factors. The investment in Lions tours and overseas placements has enabled several of this squad to arrive with some familiarity for the conditions. So has England's superior fitness and agility in the field. Indeed, the fielding is the biggest point of difference between these two sides. Had Stokes missed with his shy at the stumps or Keaton Jennings, at short leg, not been able to parry the ball to Ben Foakes for that catch, Sri Lanka could well have won.

And, while Root deservedly won the Player-of-the-Match award, there were really significant innings from Rory Burns, Ben Foakes and Curran that played huge roles, too. Root is quite right when he credits the entire side.

It was an especially significant performance for Leach, though. Not only did he register his first five-wicket haul in Test cricket, but he returned to a ground where he had endured one of the lowest points in his career and came away victorious.

For it was here, in February last year, that Leach was left out of the England Lions side for the first unofficial Test against Sri Lanka A after struggling with his new bowling action. Despite finishing the 2016 season as the second-highest wicket-taker in Division One of the County Championship (he claimed 65 at 21.88), Leach had missed out on selection for the tours to Bangladesh and India and was then found to have an illegal action during routine tests at the national performance centre in Loughborough.

Remedial work on his action had, initially, appeared to have gone well. But, playing a warm-up match on the tour, Leach went for 68 in 14 wicketless overs (the other specialist spinner, Ollie Rayner, took three for 55 from 22 overs by comparison) and was subsequently left out of the unofficial Test that followed.

To have come back from that low and bowled England to victory in Asia is a remarkable achievement. It demonstrates courage, resilience, determination and a huge amount of hard work. He, and England, deserve all the praise that comes their way.