Yasir Shah doesn't do half-measures; anyone who watched him play in England in 2016 will know that.

A match-winning ten-wicket haul at Lord's was followed by arguably his worst career performance in Manchester, his match figures reading 66-6-263-1. If his numbers in the UAE, where he's snared 113 wickets in a scarcely believable 17 Test matches, showcase the best of the legspinner, the other side of the coin is equally extreme. In the Southern Hemisphere, Yasir's nine wickets have come at almost 96 apiece at an economy rate of 4.40.

England is the one place where the jury was out on him, and he did himself few favours on Thursday. Brought on to replace Mohammad Abbas and Shaheen Afridi with all the pressure on the England batsmen, the legspinner couldn't have asked for better circumstances to be asked to bowl. Far from being a stellar support act to the quicks, however, he was perhaps singularly responsible for frittering some of the momentum away, bowling much too short, far too quick, and proving way too expensive.

It is one of those intoxicatingly captivating vagaries of cricket that Yasir walked off at the end of the second day having taking the prized wicket of Joe Root, while Mohammad Abbas and Afridi were empty handed after a sensational hour of bowling on the third morning. Even so, there were signs he wasn't over the loss of form and confidence that had meant he was no longer viewed as an automatic selection. In seven overs, he conceded 38 runs, bowling at least eight long hops along the way.

On Friday, however, his entry into the attack elevated the quality of the bowling, and as the wickets began to come, his confidence, so integral to his performances throughout his career, began to grow. He went through Jos Buttler's defences with one that might be deemed natural variation, but Yasir felt he had outwitted him, and to a confidence cricketer, that made all the difference. The long hops were gone, the delivery stride was measured and deliberate, and the stock delivery nicely flighted.

All the variations came out; the classical legspinner which reared up claimed Dom Bess, while Chris Woakes was undone by the slider. These were tricks Yasir wouldn't have dared try the previous day, and when he holds back, he is a shadow of the cricketer Pakistan have shut their eyes and hung their hopes on for so many years.

No one, as the cliché goes, becomes a poor bowler overnight, least of all a man who became the quickest to 200 Test wickets in history. The knowledge he suddenly had to prove his worth to the side may well have played a part in the added pressure on his shoulders; Pakistan's spin bowling coach spoke about it in the press conference afterwards.

"The most important thing is spinners need to have a strong temperament and understand your action," Mushtaq Ahmed said. "Legspinners need to be mentally strong, and in the right head space.

"You need to have repeatable actions to bowl good overs rather than good balls. We're working with him on how to bowl in different circumstances using various strategies, and to ingrain these into his muscle memory. If you have variations, as Yasir does, and can also bowl good overs, I think you can challenge any batsman."

It's hard to overstate how worried Yasir might have been for his future overnight. When Pakistan commemorated the first Test to be played in the country for a decade last year, he found there was no place for him in the eleven. He might have served them well in the UAE; indeed, might have been the most significant reason Pakistan went nine years without losing a Test series in the Emirates, but this was Pakistan. And in Pakistan, pace was primary, spin peripheral.

He got his chance in the second Test two months later, but if anything, served to only vindicate the decision to leave him out the first time around, conceding 127 runs at four per over, with Haris Sohail outbowling him. After the Test against Bangladesh in February - his skipper, Azhar Ali, spoke pointedly about his "changing role in the side".

"When non-Asian opposition comes to Pakistan, we'll see if we go a different direction with the surfaces but for now I think the fast bowlers have been given the task of leading," Azhar said then. "Yasir, who has undoubtedly been a champion bowler for us and has proved how good he is, will begin to get those big wickets whenever the conditions are more favourable for him. This is a change for him, too."

It sounded more like a swansong than an endorsement. There was little Yasir could have done about Pakistan moving back home, but his performances of late outside the country hadn't quite helped his case, either. In the last six Tests before the ongoing one, Yasir took six wickets at over 70 runs per dismissal; half of those were three Bangladeshi tailenders in a foregone conclusion in the fourth innings of the Test in February. In one three-Test series prior, he had managed 29 wickets. That, of course, was a UAE series.

On Friday, Shadab Khan spilling a regulation catch was all that separated him from a first five-for since that productive series in the UAE against New Zealand in 2018. But for a man who no longer has the dustbowls of the UAE to fall back on, it's unlikely to be any more than a minor irritation. His captain may believe his role in the side has changed, but Yasir will be keen to emphasise his importance to it has not.

Danyal Rasool is a sub-editor at ESPNcricinfo. @Danny61000