It was, in this tale of two spinners, the best of times and the worst of times.

While Jack Leach spent much of the day craning his neck to see how far back the latest six off his bowling had been hit, his former apprentice, Dom Bess, cut through the best middle-order in world cricket. To claim any of Virat Kohli, Ajinkya Rahane, Cheteshwar Pujara or Rishabh Pant might have been considered an admirable achievement: to claim all four is exceptional.

And yet, beneath those figures, there's a more complex picture. Because statistics don't just mislead. They lie and cheat and insist the cheque is in the post as they try to sell you a time-share in Fallujah.

For the truth is that Leach bowled perfectly reasonably. He just happened to be the victim of an assault on his bowling by Pant that, on another day, could have resulted in a wicket. And while Bess, at times, bowled nicely, he would also be the first to accept his control slipped as the day wore on and he enjoyed more than a little fortune with a couple of his wickets. The point is, the difference in figures was far greater than the difference in performance.

Bess is earning quite a reputation as having something of a golden arm. His five-for in Galle, not so long ago, contained some outrageous luck: Niroshan Dickwella slicing a long-hop to point, for example, or Dasun Shanaka caught after his slog-sweep cannoned off the short-leg fielder and into the gloves of Jos Buttler.

And, as he claimed two more wickets here - both men in the top eight of the ICC's Test batting rankings - with a full toss and long-hop, it was hard not to wonder how long his winning streak could last.

What isn't necessarily recalled so rapidly, is the missed chances he has suffered. The stumping and catch missed by Buttler against Pakistan, for example, or the slip catch missed by Ben Stokes against West Indies.

Yes, Bess has had some fortune of late. But he has now taken 16 wickets in two-and-a-half Tests this year at an average of 19.37 apiece. For how long can such success be ascribed to fortune?

And he did, at times, bowl really well here. He dismissed Kohli, for example, at the end of a probing spell that saw him build pressure on one of the best batsmen of his era. After 17 deliveries against him had produced just four singles - Kohli had, in all, faced 47 deliveries for his 11 runs and was without a boundary - Bess pushed one a little wider, saw it drift further before it turned just enough to take the inside edge.

Might batsman error have been a contributory factor? Of course. But England had frustrated him for more than an hour and Bess had lured him out of position with that drift and punished him with that turn. It was a nice piece of bowling.

"It's certainly up there with the most satisfying wickets of my career," Bess said. "Obviously he's a phenomenal, world-class player. But it was special more for what my process was.

"It wasn't about bowling that magic ball. It was about smashing in 10-15 balls in a good area. Then something will happen. It's the process of getting there. I was really pleased that I kept him in a spot, then one has gone and it's straight to Ollie Pope."

The wicket of Pant was reward for some decent bowling, too. Bess knew Pant would come at him. But he continued to toss the ball up. And, this time, he added a bit of width, too, so that when Pant came down the wicket, he was always reaching for the ball. The hint of turn was enough to draw a slightly false stroke. Again, was the batsman at fault? Of course. But Bess set the trap and executed the plan neatly.

It's hard to find many compliments about the long-hop that dismissed Pujara, though. On most days, such balls will go to the boundary. But today, Pujara's pull stroke thumped into the back of Pope at short-leg and looped to Rory Burns at mid-wicket.

By then, Rahane had been brilliantly caught by a diving Joe Root at cover. To some extent, he had been set-up by the previous deliveries: Bess troubling him with drift and coming close to having him caught at mid-wicket a couple of balls previously. And the ball he attempted to drive did dip, too, contributing to the false stroke. The fact is, though, Rahane hit a full toss to a fielder. It would be disingenuous not to acknowledge the element of fortune.

And that's fine. The vast majority of wickets are a combination of good bowling and batsman error. So when Bess pointed out afterwards he was "due a bit of luck", it was hard to disagree.

"I'm not bothered how the wickets come," he said. "There's so many times you bowl a good ball and don't get anything. You're due a bit of luck aren't you?"

But Leach didn't enjoy any such fortune. At one stage, Pant hit him for four sixes in seven balls. After eight overs, he had conceded 77 runs. It looks ugly, doesn't it? They are worse figures than Simon Kerrigan endured at The Oval in 2013. And that was a game which proved a turning point in Kerrigan's career.

But while Leach was, like Kerrigan, hit out of the attack, he wasn't hit off his stride. This was more a case of fine batting than poor bowling. And while Pant was clearly the victor in the duel - he scored 48 in 21 balls from Leach, including five sixes (all in the arc between mid-wicket and mid-on) and two fours - there was hardly a poor ball in there. Instead Pant, recognising the potential danger of Leach gaining assistance from the foot marks outside his off stump, backed himself to hit the bowler out of the attack. It was a high-risk approach, but it worked.

But given just a bit of fortune, Leach might have won this tussle. Twice he saw the ball pass agonisingly close to the boundary fielders set for the stroke. At no stage did he lose his composure; at no stage did he lose his line and length. He basically came up against a fine player who took a chance and saw it come off. It happens.

There was a case for persevering with Leach in the attack. England were defending a mammoth first-innings total of 578, after all, and Pant only needed to mis-time one. But instead, Root fiddled his bowlers around and, having frustrated Pant with an over of his own bowling - firing the ball into the rough outside off stump and conceding only a single in the process - he saw Bess benefit from his frustration in the next over.

"I thought Leach bowled really well," Bess said. "And that's not me just saying it. Pant played a phenomenal innings, but if one goes straight up in the air, it's a completely different game. I know people will look at the outcomes; I know at one point he was going at 10 an over. But it doesn't matter: I thought he bowled really well."

The data would appear to support that view. Leach hasn't bowled a single full toss in his 17 overs to date. And while he has dropped short 10 times, none of those deliveries cost him a boundary.

Bess, by contrast, has bowled 10 full tosses and 16 short balls in his 23 overs to date. And while those deliveries cost him 27 runs, they also brought him two wickets.

Leach's pitch maps to Washington Sundar and Pant were almost identical, but Sundar took him for a far more reasonable 17 runs from 39 balls. It seemed to sum up Leach's day when Jofra Archer, running back from mid-on, dropped Sundar off him near the close.

So, hard times for Leach. But as Bess said, we must guard against judging these things from the "outcomes". In terms of consistency, Leach was the better of the two bowlers. In time, you would think, his luck will turn.

George Dobell is a senior correspondent at ESPNcricinfo