As much as the delivery it is the exclamation - a kind of song actually - it prompts from the wicketkeeper that is worth replaying. It is such an unmistakably subcontinental reaction, audible in any number of scenes - among a group of men after a lewd joke, or, more deplorably, when a beautiful woman passes by. At a mushaira [poetry recital] or a mehfil [small gathering], you may have noticed, a clever couplet brings this on: this, Ai hai hai hai. Umer Sharif, the great Pakistani comedian, was a master enabler of such moments. Occasionally if it is just too good, one might feel the urge to punctuate it with a "Maar da laa" [That killed me].

Sarfraz Ahmed did not so append, and why would he? His Ai hai hai hai to that delivery from Yasir Shah was enough. Words might be the worst way to capture the mastery of that delivery over its victim: this explains it sufficiently. Years earlier, Ashraf Ali expressed a popular variant, a softer, more lyrical but abrupt Aa haa to an Abdul Qadir googly that castled Kim Hughes (if you're in a rush, watch from around 4:00 but this is Qadir googly heaven, so you'd be a fool not to watch it all). The bonus - and locator of surrounds - in this instance is Richie Benaud's excitement on the mic ("Beautiful Bosie!") but Ashraf could easily have been an appreciator of some form of subcontinent art: a dance performance, a poetry recital, a music concert, a filmi dialogue.

Moin Khan was an occasional champion of it, as he still is in gatherings of adult men, amid childish jokes. But as with Sarfraz and Kamran Akmal, the loud cackle was his go-to reaction to a batsman's misfortune. Moin once started laughing two-thirds of the way through appealing for lbw off a Mushtaq Ahmed googly to HD Ackerman. It helps to have the voice of Moin and Sarfraz, squashed down but trembling forever on the brink of a screech. It isn't necessary, though.

Rashid Latif was an oddity among Pakistani wicketkeepers in many ways, one of which was that he possessed a deeper voice. He was not as vocal either, but even he couldn't help pulling out a slightly stretched "aah ha", when Mushtaq once bowled Dermot Reeve with a googly, or a droll "ai hai" when Mushy did likewise to a UAE batsman (in the same video, soon after the Reeve dismissal). The more refined response alerts us not only that the ball is good but that the entire dismissal is to be processed as a piece of high culture.

"Unique within team dynamics, the wicketkeeper must treat the leggie as an opponent to be conquered. He must learn to read him as a batsman does, but from the hand"

MS Dhoni has the voice and bearing for it, though nobody should be surprised that he has elevated his version to a tool of proactivity. He uses it as a kind of spook tactic, for deliveries that do not take wickets but might do something special. What they do is plant doubt inside a batsman, or at least the hint that a collaborative mischief of personnel and the elements is upon him. In that way, as Dhoni must have worked out years ago, it is as good as a sledge. In the event of a wicket falling, it is a send-off, a withering one without a word even being uttered. "Ai hai hai, maar da la" - batsman, keeper, everyone, figuratively, literally.

****

Cricket does not easily forget a big-turning legbreak, such as the one Yasir bowled to Imrul Kayes. Perhaps it is because we understand the impossibilities of what is being done. It is the only occasion in life, for instance, other than when a ring is being put on it (or it is used to pick a guitar string) that our third finger from the thumb comes to some labour. The wrist must unfurl in synchronicity. And already the shoulder is going through a highly unnatural contortion, with incredible strain put upon it. Subsequently there is the pivot on the foot to consider, as well as the driving of the hips through the process of release.

These are just the bare biomechanical considerations, but already requiring a rare combination of strength and dexterity. Then come the specific skills. The seam has to be positioned right; there must be enough revs imparted on the ball to first make it drift, then grip and then turn, but not do any of it too much or too little; the release has to come just right, otherwise the ball lands too short or too full, or comes out too flat, or too loopy.

We might think then that the chances of a confluence as magnificent as that delivery of Yasir's - a perfect storm of anatomical gifts and acquired craft, of nature and nurture - lie somewhere between Leicester City winning the Premiership and the force of the Big Bang being just right to produce a cosmos. Or something.

It is almost irrelevant that he gets the wicket at the end of it, let alone that it is a castling. Would it have been worthier to beat a defensive stroke, such as the one Mike Gatting bemusedly offered Shane Warne, or to bypass an attempt to pad away the ball? Maybe, because to beat a man when he is determined not to be beaten - as opposed to when he is determined to win - appears the harder feat. But to lull a batsman into attacking and then get him is also a triumph in the battle of personality, just in a different way to how Warne conducted it. And just for fun, try in your head to superimpose the sound of a Moin or Sarfraz to a Warne wicket: ecstasy.

Something of the sheer wonder of legspin has necessarily dimmed over time. When Qadir was legspinning, it was the easiest thing in the world to shroud him and his craft in mystery. There was no video or internet, no coaches or analysts or biomechanists breaking his action down. He could bowl one googly six times but Chinese whisper it into meaning he was bowling six different ones, and nobody was in a position to dispute it. Growing a goatee was a legitimate bowling tactic then. By the second half of Warne's career, he would have had to work harder to make the batsmen in his era think something was happening when it wasn't, because batsmen were better equipped to know what was and wasn't happening. It was Warne's genius that he could still do it, even as the game and his own pre-eminence within it made it harder for him to do so. Yasir may as well be bowling naked, there is so little to hide in this age.

Maybe not all the wonder has gone, though. It is still the genre of bowling most given to producing oohs and aahs and ai hai hais. Warne probably didn't see the ball Yasir bowled but such is the brotherhood, wherever he was, in his head, maybe in his sleep, he must have felt it and appreciated it: "ai hai hai".

****

The legspinner and his wicketkeeper: this summer in England, Yasir and Sarfraz must forge a partnership. It is not a partnership as we understand others to be, between opening bowlers or batting pairs. These are two lonely occupations, one man often only noticed for his mistakes, the other usually the only representative of his kind in a bowling attack. And legspinners do not breed easily, so each one carries the flame for a species, not just for himself or his side.

"Warne probably didn't see the ball Yasir bowled but such is the brotherhood, wherever he was, in his head, maybe in his sleep, he must have felt it and appreciated it"

Unique within team dynamics, the wicketkeeper must treat the leggie as an opponent, to be conquered. He must learn to read him as a batsman does, but from the hand, because unlike the batsman, the wicketkeeper's line of sight is directly obstructed. The wicketkeeper strives to understand what the leggie is doing better than anyone on his side, and that, perhaps, is why he responds as Sarfraz did in that dismissal. That exclamation is part of the bond that he knows and appreciates better than anyone just what the leggie has done.

It is not an obviously prolific partnership. Unlike the prominence of a fast bowler and his wicketkeeper, or the more celebrated associations of spinners and slip catchers, this relationship demands less exclusivity to each other. Take a sample of modern leggies (Qadir, Mushtaq, Warne, Anil Kumble, Stuart MacGill and Danish Kaneria), and you'll find that on average, 15% of their Test wickets were either caught or stumped by a wicketkeeper; for some, like Kaneria, the proportion is nearly a fifth, for others, like Kumble, it is less than a tenth. On average, they do not even combine for one dismissal per Test - from this sample, Kaneria-Kamran Akmal came closest, with 39 dismissals in 43 Tests together.

Kevin Pietersen was bowled trying to sweep Shane Warne Getty Images

That last stat is a statutory warning to not burden these numbers with excessive meaning. Kaneria-Akmal began well but the dysfunction that grew between them from 2006 was central to dysfunctional sides. Kaneria never said so publicly at the time, but each time he came on to bowl, he did so with zilch faith in Akmal's ability. Instead, when they are operating together there must be no misunderstanding, no gripes or masked frustrations. Communication is vital, even if it is just to ask what's for dinner tonight before the last ball of the day. A good, working combination becomes a useful index of the health of a side.

Sarfraz's work to spin, and to Yasir, has not always been assertive; that they have combined for just one catch in 12 Tests is not simply the by-product of how these pairings operate but the result of several missed chances. Conditions in England for the uninitiated wicketkeeper, as Akmal discovered a decade ago, can be so unique as to derail a career. Not many chances will come in the first place, so the price of Sarfraz not holding on to the few that do will be steeper.

There is some promise, not least among seven stumpings. The one to get rid of Dimuth Karunaratne last year in Galle, off a ball that turned a mile, emerged from within the tangle of an attempted shot and was rising another couple when Sarfraz took it, was a peach. This was not as swift or smooth as Ian Healy's celebrated stumping of Graham Thorpe in Perth once - to a Warne delivery that he took shoulder high. That was unreal. But Sarfraz did finish this at least, with function if not form. A couple against England last year similarly offset an inherent clunkiness with the alertness to get the job done.

Given how their leggie and wicketkeeper have gone on the last two tours of England, Pakistan won't care much how it is done, as long as it is.