In 2019, Paul Stirling had a decision to make. When Ireland were awarded Test status in 2017, the ECB provided Irish internationals with a two-year grace period in county cricket, after which they would only be able to play as their side's overseas player, rather than as locals - unless they quit international cricket.

As a British passport-holder, Stirling admitted that he was "baffled" at the situation, but decided against a legal challenge and was left a choice between renewing his contract at Middlesex, where he had spent 10 years as a professional, and extending his international career.

While some of his Ireland team-mates opted for the security and stability of a county deal, Stirling chose the other path. "When he texted me to say he had committed to Ireland and wasn't going to continue with Middlesex, I was delighted," Andy Balbirnie, Ireland's captain, recalled. "Every team around the world would want him."

It is easy to see why he was so enthusiastic. Once a dasher who would throw his hands at the new ball and hope, Stirling has become one of the world's most consistent opening batsmen, especially in 50-over cricket, the format which comes most naturally to him. Since international cricket restarted in July 2020 after its Covid-enforced hiatus, Stirling has made four ODI hundreds in eight innings; Steven Smith, with two, is the only other batsman to have compiled more than one.

While it had never been in doubt that Stirling was a player with bags of natural talent, there had been legitimate questions a decade into his international career as to whether he would reach his potential.

Having made his debut at 17, Stirling's ODI average was an impressive 42.48 after 32 innings, with a strike rate of 95.43 denoting his aggressive style at the top of the order. In his next 40 innings, he lost his way: he passed 50 only four times, averaging 24.82 across a six-year period which even included a fleeting shift down to No. 6 as a ploy to combat Afghanistan's spinners.

But in his 50 most recent innings, dating back to March 2017, he averages 49.22, with a more conservative strike rate of 84.57 demonstrating the extent to which he has reined in his instincts and adapted his game to perform the role of a senior batsman in a team in transition. Seven of his 12 ODI hundreds have come in that time, with his three in Abu Dhabi this month taking him past William Porterfield's previous Ireland record of 11. He dedicated the most recent two, against Afghanistan, to the late Roy Torrens, whom he described as "an absolute hero".

In particular, Stirling has been exceptional against spin, a quality that might not be obvious in a player brought up on green Belfast pitches. Since mid-March 2017, he has scored at a marginally slower strike rate against spinners (83.33) than seamers (86.11), but his average of 78.57 facing spin is up there with the world's best, after honing his methods against Afghanistan's 'big three' - Rashid Khan, Mohammad Nabi and Mujeeb Ur Rahman - and the best in the associate game.

Essentially, Stirling realised in his mid-to-late 20s that it was no longer enough for him to swing through the line and hope. "You get bored of getting to 30, hitting it in the air and getting out," he told ESPNcricinfo earlier this month. "From there you think, 'actually, I quite like batting - maybe I'll try and bat a little longer'.

"I got off to a really good start in ODI cricket and I probably took it for granted a little bit. I think it's my favourite format - it's the one where I feel I can just bat. To me, that's the most natural you can be. I can walk out there and not have to think too hard, and naturally strike the ball well and score at a strike rate that's OK."

Rather than any major technical changes, Stirling attributes his improvements over the last four years to a shift in mindset. He still attacks in the powerplay when he can, but not at the expense of throwing his wicket away. "It comes down to experience. I definitely had a shift. I think I was averaging 40-plus in ODI cricket and it slid down maybe even into the early 30s. That's when I was like 'right, it's time to make some improvements here'. You ask yourself, 'what do you want, to score quick 30s or make match-winning scores?'"

In particular, he hails the influence of Graham Ford, who sat him down upon becoming head coach in December 2017 to tell him that he would not settle for sporadic brilliance. "He made his point very clear, which was that I'm here to score runs, not to score pretty 20s and 30s to stay in the team," Stirling recalled. "I thought that was good. If he hadn't done that, I could have just continued on my way, so he was certainly a big help." When he became vice-captain last year, it seemed like a natural fit.

As a result, Stirling's recent record puts him in the company of the best in the game. Since the start of 2019, only Aaron Finch and Rohit Sharma have more ODI hundreds than him, and while their innings may have been against stronger opposition, they have not had to carry the rest of their respective batting line-ups in the way that Stirling has; in that timeframe, Stirling has scored 1351 ODI runs, while only one team-mate - Balbirnie - has breached the 500 mark.

The upshot is that Stirling has levelled up by slowing down. Once Ireland's free spirit, he has turned into a relentless run-scorer by embracing responsibility.

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