So much to enjoy, and even marvel at, in that victory over Crystal Palace: the craft involved in the two goals, the confidence-boosting preservation of the clean sheet, the growing sense that this evolving young side is developing not just the guile but also, just as important, the patience to get beyond opponents who have basically decided to stack themselves like bricks across their penalty area... all of this was deeply pleasing.And the fact that these things happened despite the enforced absence of Jorginho, who has seemed to be central to so much of what the team has been achieving during this long run of form... well, that didn’t exactly detract from the experience, either.

And then, as if we weren’t all going to be leaving happy enough, there was the high-value novelty moment when the board went up for time-added-on at the end of the first half, when, once again, a team of officials led by Mike Dean showed an almost uncanny ability to blindside a paying crowd and deliver the truly unexpected.If it was a surprise to see only four minutes added to the end of the monumental Champions League game against Ajax – rather than, say, 10 minutes, or perhaps a quarter of an hour, which would have been closer to the reality of it – it was surely equally baffling, but in an entirely different direction, to see the same sum added to the end of the first half against Palace.Four minutes before half-time? A true ‘where were you when…?’ moment there. The pre-interval totaliser ticking above one or two is not something you often see, except in wildly exceptional circumstances – following a serious injury, say, or perhaps after a disruption to play caused by the arrival on the pitch of alien life forms.And it’s certainly not something you often see after a first half which hasn’t even produced a substitution, let alone a complicated injury or an invasion from another world.

In fact, maybe you’ll remind me, but I actually can’t remember a fourth official holding the number four above his head before an interval at Stamford Bridge in the entire age of the electronic board. Four whole minutes! It’s sobering to reflect that, if you had popped out for your tea and crisps in the 86th-minute last Saturday (madness, of course, although people do it), you would have gone into the second half having missed practically a sixth of the game to that point.A mystifying calculation, then – four minutes conjured from practically nowhere – in stark contrast to the previous Tuesday when four minutes merely hinted at the period of additional time we should have seen, and when a more accurate figure might have turned a supremely impressive draw into a staggeringly impressive win.Let’s be serious: against Ajax, the six substitutions alone, at the statutory rate of 30 seconds per sub, would give you three minutes, and that’s before you factor in the massively prolonged red card furore which left Jorginho standing over the penalty spot for another three minutes, minimum, and before you add anything to compensate for the time-wasting by our esteemed visitors on either side of that moment and the actual injuries requiring on-field attention on both sides.

Now, one hesitates to bring up the exhausted and exhausting topic of VAR again. But is it not odd that football can now apparently rule on offsides invisible to the naked eye, most recently gauging the depth of a Sheffield United player’s toenail to rule out an otherwise perfectly respectable goal at Tottenham, yet cannot perform an accurate calculation of the time due to a match at its end? How come there isn’t anyone in the Premier League’s magic video cupboard over at Stockley Park who possesses a stopwatch, or even (it’s 2019, after all) a laptop with some smart software?Like a horse-drawn cart in the age of petrol, time-added-on remains this oddly archaic entity – a number plucked casually out of the ether and rounded up or down by the officials according to taste. Perhaps the most priceless paragraphs (among many) in the autobiography of Jeff Winter are the ones in which the now retired Premier League official recounts how, in his last game at Anfield, he allowed additional time to run a little longer than the amount stipulated so that the ball was up near the Kop when he blew his whistle, meaning that the roar of the crowd on this (for Jeff) emotional occasion was that much louder in his ears.

I am not making any of this up. There we all were, assuming time-added-on was a carefully arrived-at assessment of the potentially vital seconds lost to play by undue interruptions. On the contrary, it turns out it’s an elastic, dramatic device, there to satisfy the referee’s sense of the day’s broader drama and his place in it.

Now, Winter was, of course, in so many ways, an exception. But even so, while expensively purging interpretative human error from the offside situation, in the fundamental matter of how long a game lasts, football still urges us to trust Mike Dean’s gut instinct. In other words, you’ve got a set of minutely calibrated, toenail-measuring tolerances in play at one end of the sport, and one bloke’s broad guesstimate in operation at the other.

There’s a glaring and absurd contradiction here. The game now has a bunker full of computers and supplementary PGMOL officials in full matchday kit, yet it can’t reliably perform a basic calculation regarding the duration of a match. Yet, unlike offsides and handballs, this is an area of the game that would actually lend itself to maths.

VAR: we’ve found you a job. And what’s more, it’s one that nobody will mind you doing.

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