Since Dawid Malan's T20I debut in June 2017, he has been a revelation for England and has surged to the top of the ICC's individual batting rankings. But in that period, there has been a marked difference between his record in T20Is and in domestic T20s: his average in an England shirt is almost twice as high as in the colours of his various clubs, while his strike rate is significantly higher too. What explains the discrepancy?

Pitches are better at international level
Groundsmen generally have more time to prepare pitches at international level, and aim to hold marquee fixtures on the best strip they have available to them. As a rule of thumb, that means conditions are better for batsmen. Malan has also played six out of his 19 T20Is in New Zealand, predominantly on grounds with very short boundaries, and has scored 320 of his 855 runs there.

He has said previously that having to adapt to conditions throughout his franchise career has made things seem easier on better batting pitches at international level. "It's undervalued how important these tournaments actually are to a player's development: you go to Bangladesh and you could play on a 200 wicket on the Monday and on the Tuesday, it's a 120 wicket," he said last summer. "You're consistently learning how to adapt and read conditions, which I think is one of my strengths in T20 cricket."

Those experiences have proved particularly useful against spin: he has scored marginally quicker against pace than against spin in domestic T20 cricket across the last three and a half years, but on international pitches that have been less conducive to spin, he has scored at a strike rate of 160.66 against spinners compared to 141.44 against seamers.

The freedom to go big
Malan bats in the top three, meaning that how he plays is determined in part by the resources his team has available lower down the order: he has freedom to attack earlier in the innings for England, knowing that Eoin Morgan is due in as low as No. 6, than he does when he is part of a franchise team with much less batting depth.

England have stacked their batting in T20Is over the past four years. Chris Jordan, Jofra Archer and Adil Rashid came in at Nos. 9-11 in their most recent series in South Africa. The result has been that Malan has had licence to attack, and while he has a penchant for playing himself in, the strength of the batting below him in the order has given him the opportunity to play his more expansive shots at an earlier stage, rather than feeling the need to wait until the final few overs of the innings.

The evidence backs that theory up: in T20Is, his strike rate in the six overs after the powerplay (from the start of the seventh to the end of the 12th) in T20Is is 20 runs clear of his strike rate in that phase of the game in domestic T20s.

He has worked for it
Malan prides himself on his preparation, and knowing all the relevant information about a team's bowling attack. Heading into bilateral international series, there is time to prepare to face a particular attack, in the knowledge that personnel are unlikely to change significantly across a handful of games. In franchise and domestic cricket, preparation time between games is often shorter, leaving him less time to mug up on upcoming opposition.

"I'm so big on preparation," he said in a Professional Cricketers' Association interview in October. "It doesn't mean that you're going to perform but it just gives you that extra slight edge to be a bit more consistent than you are when you're playing county cricket and you play, travel, play, travel without being able to get into any rhythm on off days.

He has also been able to make use of his extensive franchise experience while playing international cricket: last summer, he played with or against most of Pakistan's bowling attack during his time in the PSL, while during the series in South Africa, he made use of his experience facing Anrich Nortje and George Linde in the Cape Town Blitz nets during the Mzansi Super League.

The luck of the draw
Malan is the exception to a T20 rule in that his international record comfortably outstrips his domestic one, which is even more remarkable given he is yet to make an appearance in the domestic league where the standard is highest - the IPL. The natural response is to look for explanations in his method or technique as to why that is but it is possible that Malan has performed at an unsustainably high level for England.

"If you were to play 30 games in a row, you're going to have that slump in form, whereas if you're missing out every now and again, you probably don't have that slump in form if you come in at the right times," Malan has acknowledged. "I've been quite lucky with that."

He has missed out on selection at the right time: he struggled in the MSL, BPL and PSL in the 2018-19 winter, and was a non-playing squad member in England's series in the Caribbean, while in 2019-20, he played only once in the South Africa T20Is, making a scratchy 11; playing all six of those games while out of form might well have damaged his overall record.

"There have been times when I've been left out of the team when I've probably been batting really badly," he has said. "As disappointed as you are to miss out, you know you're probably not playing as well as you could. But the times that I've been given opportunities, I've actually been hitting the ball well and I've been pretty confident."

While his T20I career spans a four-year period, he has still only played 19 matches. He has been excellent throughout - "remarkable, really," according to Morgan - yet it remains plausible that his international record is something of an outlier. Malan has an unspectacular domestic record in the last three and a half years but a world-class international one; perhaps his true level as a T20 batsman lies somewhere in between the two.

Matt Roller is an assistant editor at ESPNcricinfo. He tweets at @mroller98