Maybe there's some psychology involved and maybe there's some technique, but it made perfect sense when Ben Stokes revealed he had been watching footage of his batting in the 2015 Lord's Test ahead of this innings in St Lucia.
That match against New Zealand was the one in which he recorded an 85-ball century - the fastest-ever Test century on the ground - to set up a remarkable victory. He made 92 in the first innings, too, after England had been 30 for 4.
Batting seemed simple for Stokes in those days. He had been told ahead of that game that he was going to be given a permanent spot at No. 6 - he had batted at No. 7, No. 8 and even No. 9 in previous months - and was given the freedom to play his naturally aggressive game while Alastair Cook made a typically sedate century at the other end. It looked as if England had found a special player. And the way to get the best out of him.
Life has become more complicated since. Not only has more become expected of Stokes, but England's top-order has not always given him much protection. He has also been through a legal ordeal that put him in the spotlight for all the wrong reasons for several months and threatened, for a period, to turn his life and career upside down.
That episode may have changed him. This was only the fifth time he had reached fifty since the incident in Bristol in September 2017. Before it, he averaged 35.72 in Test cricket. In the 12 Tests since, he had averaged 24.83 with a top score of 66. This was the first time he had reached 50 in the series.
There is no obvious explanation for that decline. He looks, against spin in particular, a more solid, tight player with a technique that could probably cope with promotion up the order. Not so long ago, he batted at No. 3 in Sri Lanka.
But so much of this game is played in the head. And somewhere over the last 18 months or so, Stokes has become a more introspective batsman. A more cautious, thoughtful batsman who sometimes seemed fearful of unleashing the strokes we know he has. Since Bristol, his Test strike-rate has been 45.46; before it was 63.77.
Why would that be? One theory is that Stokes is trying to compensate for the trouble caused in those days. Painfully aware of how his team-mates struggled in Australia - both on the pitch, where they missed him terribly, and off the pitch, where they were subject of endless scrutiny - he is, perhaps, trying to take on too much responsibility for their fortunes now.
Equally, he may have felt the need to take on more responsibility given the struggles of England's top-order. Forced into a rebuilding job almost every time he comes to the wicket, Stokes may feel the side cannot afford him to fail. As a result, the natural stroke-maker has gone and, in his place, is a careful, cautious accumulator. It's not the role he was born to play.
So, over the last few days, he has tried to connect with the version of himself that was so impressive at Lord's in 2015. He has, he says, gone back to a similar technique and guard, and taken some confidence from the memories of a fine performance.
"I actually looked at some footage of me at Lord's this morning," he said after play. "I've been thinking about going back to that technique: straightening my feet up and batting with an off stump guard. I've been working with Mark Ramprakash [the batting coach] on it for the last couple of days.
"I was just trying to find some levelness: not being too aggressive, but not being too defensive. I thought I had been a bit stuck over the last couple of months. Watching myself at Lord's did me the world of good."
It's probably no coincidence that Stokes enjoyed a bit of protection here. With the top-order managing to survive a little longer - as much by chance as judgement in the case of Keaton Jennings, who endured a torturous innings - Stokes came to the crease later than at any stage in the series. As a result, the ball will have been a bit softer and the bowlers just a little less fresh.
He had some fortune, too. He survived a leg-before review on 6 - replays showed the ball was clipping the stumps, but Stokes survived on the basis of 'umpire's call' - then came within a whisker of playing on when he had 11 - the ball whistled off an inside-edge for four. Most remarkably, he had already left the field after being caught and bowled on 52 before replays showed the bowler, Alzarri Joseph, had over-stepped. Later, with the fast bowlers resting ahead of the second new ball and West Indies desperate to mend their tardy over-rate, he also had the opportunity to take some relatively soft runs from the spinners.
But at other times this was a really tough examination of his abilities. Shannon Gabriel bowled with excellent pace - he touched 92.7mph at one stage - while the pitch showed signs of variable bounce. Indentations, caused by the ball new hitting a damp surface in the first hour, may now have baked in and may yet come back to hurt West Indies. It may have been reasonable to bowl first, but the opening spells with the new ball were not especially searching and batting last may be more problematic.
Stokes, however, showed an ability to change gear when appropriate. He scored 41 of the first 50 runs made in partnership with Jos Buttler - not a bad effort while batting with a man who has made the quickest ODI century in England's history - before reining it back in to ensure England resume in the morning with a great deal of power to add. This is already England's highest partnership of their winter.
This wasn't, by any means, vintage Stokes. But it was encouraging and did suggest he was finding a way to combine his natural strokes with his improve technical skills. If he get back to something approaching his best with the bat, England will immediately look a much stronger side.