Pedro Porro hit the post in the 94th minute. It was an opportunistic shot from a tight angle, about 20 yards out. No kind of angle for a shot, really. But it was struck well, fierce and swerving viciously away from David Raya in the Arsenal goal, who probably wouldn’t have saved it. The frame was still rattling several seconds later.

So, here’s a thought exercise. What are the consequences if Porro’s shot goes in? Does it make this Tottenham team any better? Does it change our assessment of their season so far? Does it render the club any better run or better coached? It shouldn’t, right? A hopeful pot-shot going an inch to the left shouldn’t mean anything beyond itself.

But of course a miracle goal in injury time of the north London derby changes everything, from the title race to the mood music around Arsenal to – very possibly – the trajectory of Tottenham’s season. And the reason for pointing all this out is that it’s becoming increasingly clear, 18 months into the new Spurs era, that this is a project whose success or failure is going to turn on stupidly fine margins.

Here Ange Postecoglou’s side had a golden opportunity to do the funniest thing imaginable, which was to beat Arsenal 1-0 with a goal from a set piece. Instead they suffered one of their characteristic bleak episodes, those few pulsing minutes when the lights start flashing, and the room starts spinning, and the voices, and the voices, and the voices. Arsenal scored two largely undeserved goals in four minutes just before half-time, and that was enough to seal Tottenham’s 12th defeat of the season in all competitions.

And again, here you can choose your own adventure. Eleven of those 12 defeats have been by a single goal, illustrating that Spurs have been supremely unlucky, or unforgivably naive, or lacking in killer instinct, or so close to being very good. This is perhaps the defining theme of Angeball: the ability to create multiple realities around itself, to add layers and layers of context until even hard facts begin to feel traitorous. So forget what you think about this team. What do we know for sure?

Well, we know that right now Tottenham are very bad. How bad? On their current trajectory they’re on course for 43 points, which would be their worst ever Premier League season in the 20-team Premier League era. Worse than the Christian Gross season, worse than the Juande Ramos season, worse than the season where they fired Glenn Hoddle and basically forgot to replace him.

We also know these players have basically been getting flogged twice a week, in a ruthless high-intensity style, since August. Look at the team who started this game. The ones who are good are knackered, and the ones who are not knackered are not good. There are times when it feels like Dejan Kulusevski is carrying this team on his lungs alone. Dominic Solanke has lost a yard of sharpness. Son Heung-min has lost a yard of pace. James Maddison is not capable of a full 90. Porro looks sketchy as hell.

Most of the rest are basically a punt on potential. New goalkeeper Antonin Kinsky is a good example: a wild and mercurial talent with abundant confidence on the ball and a habit of getting tackled maybe twice a game. The sort of player you nurture and protect. Instead, with half an hour on the clock Kinsky had taken more touches than any other Tottenham player.

And yet with 39 minutes on the clock, Spurs were ahead. All that was required from here was a little poise and patience against an Arsenal team struggling for goals, hesitant in the final third, lacking a reliable scoring threat, tense and taut and sullen and doubting themselves. This isn’t about Plan B, or shutting up shop, or compromising on a sacred footballing creed. It’s about making good decisions, staying composed, doing the simple things well. Playing 90 minutes, not just the next 90 seconds.

Instead Kinsky misjudged a corner and Radu Dragusin lost the run of Gabriel Magalhães. Instead Yves Bissouma was caught in possession when there was an elementary pass on to Djed Spence. Twenty minutes against Brighton. Fifteen against Ipswich. Twenty against Chelsea. Four minutes here. That’s the difference between a Champions League tilt and the worst Spurs side since Ossie Ardiles.

There is a really good side in here. Maybe lacking in passing sophistication, but exciting and youthful and aggressive and reared in a common style and with a devastatingly high ceiling. But it is also a side addicted to danger, impulsive and impatient, perennially on the wrong end of fine margins because this is what happens when you play like there are no consequences and infinite excuses.

It’s the injuries. It’s the poor recruitment. It’s the schedule. It’s the corner that shouldn’t have been given. This is just the way we play, mate, and we trust the process. The good times are just around the corner. And of course there is a rich irony here. In keeping the faith, Tottenham fans are displaying the kind of exemplary patience so lacking in the team representing them.