You would not have required an expert knowledge of cricket to make the visual observation that the wicket prepared for Bangladesh’s historic Test win over England was a raging “bunsen”. The pseudo-Cockney slang term (bunsen burner = “turner”) indicates a wicket particularly conducive to spin, and traditionally alien to cricketers brought up in English conditions.

What was less usual about this particular surface was that it turned from the word go and did not deteriorate as such. CricViz ball-tracking data shows England debutant Zafar Ansari was getting deliveries to turn a whopping 11 degrees on day one. The most successful bowler in the match by some distance – Mehedi Hasan, who brilliantly captured 12 wickets – was peaking at between nine and 10 degrees deep into the final session.

The BatViz slider on the CricViz app provides further evidence to support this theory. Rather than showing a gradual move towards maximum difficulty, it reveals fluctuations throughout the course of the match.

And that’s really what made the Test match quite as fascinating as it was: three big partnerships, one of 170, one of 100 and one of 99 (by England’s ninth-wicket pair, no less) and yet modest totals of 220, 244, 296 and 164. If ever there was a track where batsmen had to get themselves in before finding any confidence then this was it.

What was surprising was that only one spinner in the match consistently caused problems, and that was Mehedi – the man who turned 19 in the short window between the Tests. A fairly conventional off-spinner in style, he would have been delighted to find himself up against four left-handers in the England top six – and by bowling round the wicket to them he worried the outside edge of their bats with the one that turned a lot, and the stumps with the one that didn’t turn so much.

Mehedi removing Woakes on day two and ending a 99-run stand for England’s ninth wicket

His first wicket in the match was the key one of Alastair Cook, and it came early. The six balls in Mehedi’s first over had turned between 3.7 degrees and 6.9 degrees. The six in his second varied even more widely, turning between 2.7 and 7.3 degrees. Cook had faced 10 of those 12 deliveries and was on strike again when Mehedi bowled the first ball of his third.

This one turned the least of all of Mehedi’s deliveries up to then, just 1.7 degrees. You may have heard commentators at the time mentioning the ball “skidding on”. Well that’s partly becuse the ball didn’t bounce particularly high either – 55cm from a pitching position five metres from the stumps. A considerably fuller ball in his previous over had bounced higher. With variable bounce and variable degree of spin to account for, there was much in favour of high-quality spin even against the most watchful batting and Cook was a gonner – lbw after a successful review by the Bangladesh team.

Even good right-handed batsmen were prey to Mehedi’s variations. Jonny Bairstow, statistically England’s best batsman in 2016, had survived for almost an hour when also falling lbw to the young man from Khulna. This one was pitched 58cm shorter than the ball he had trapped Cook lbw with but bounced even less and Bairstow, playing off the back foot to give himself time to assess the degree of spin, was unable to adjust to the low bounce.

The most important wicket of all for Mehedi was Cook in the second innings. England were by now in deep trouble at 127-4 needing 273, but with their captain still there on 59, an in-form partner in the shape of Ben Stokes and a capable tail to come the beast had not yet been slain.

“I always wanted to do well whenever I got the opportunity. I didn’t really think it would be this series. It could have been any time in the next year or two. I wanted to come into the national team with a strong mentality so that I could perform well” – Mehedi

This delivery was again at the perfect in-between length. On another pitch Cook might well have played back to it, but perhaps wary of the manner in which he had fallen in the first innings, he came forward and looked to push runs into the off-side. But this was a slower one from Mehedi and it turned a fair bit, not too much as Cook would have missed it and the delivery would have been wasted but at 6.2 degrees of spin it was just right, slightly more than the average spin achieved by Mehedi through the match, and enough to locate a thick outside edge – and for the man at silly point to complete a fine catch.

Mehedi’s consistency of length was so important. He bowled 78% of his deliveries in the match on a good length, so was constantly provoking doubts in English batsmen. As for England’s spinners, they fell well short of this, particularly in the first innings where they collectively sent down just 40% of deliveries on a good length (Moeen Ali the best of a very poor bunch with a 50% ratio). And that really says it all: when you’re a slow bowler there is no substitute for being able to exert control over your opponents – just think back to the halcyon days of Muttiah Muralitharan and Shane Warne. Mehedi had it; England’s spinners did not.

There is a footnote to this blog and it concerns the value of picking a talented young player unexposed to the rigours of hard-toil professional cricket across multiple formats. Mehedi is the first teenager ever to take 19 wickets in his first two Tests.

England are famously reluctant to pick teenagers for Test cricket. One of the most remarkable stats I found during the Dhaka Test was that in all, only five teenagers have ever represented England in Test cricket. Bangladesh, who began playing Tests more than a century after England, have had 26.

And another thing: when given their head, talented youngsters have tended to do well in the bowling department. Three bowlers took 50 Test wickets as teenagers, and you may well have heard of them: Waqar Younis, Daniel Vettori and Mohammad Amir.

Bangladesh have produced four of the most productive teenage batsmen ever, including England’s nemesis Tamim Iqbal, in a list headed overall by a certain Sachin Tendulkar, who amassed 1,522 runs before turning 20.