Looking for stability

In true newsletter style, this will be a collection of thoughts. Mercifully, it’ll be short.

They’re both in the grand Get Goalside tradition of ‘the nature of football'. The first is a fourth-dimensional take on Rafael Benitez’s football tactical metaphor of the ‘short blanket’. The point is that, like a short blanket will always leave part of you cold, a defensive team will always leave part of the pitch exposed.

Football is a sport where it’s very difficult to score a goal, played for a length of time which is very long. What an absurdity to play a game for an hour and a half and, very possibly, not score a goal at all. This is the most popular sport in the world.

And so, there isn’t, and possibly never will be, a tactical blanket that a team can throw over a football match and cover it all. (Though of course, you can cover the match better or worse). The point is that in any tactical consideration, time is a factor. Not a revelation, but also not something that is talked about as much as all other tactical aspects.

Secondly, on a team level, is the idea of ‘stability’ in a team. This is a thought that stems from the perennial problem, ‘why do some teams game the progressive pass metrics?’. (Not ‘why do they choose to game them’, but ‘why do their stats look as if someone were gaming them’). At time of writing, three Premier League teams have averaged between eleven and twelve passes into the penalty area per game (FBRef) - Arsenal, Liverpool, Manchester City. By FBRef’s (Opta’s) numbers, Liverpool have created around ten expected goals more than City, and almost 20 more than Arsenal.

So, stability.

Teams attack and they defend. The ideal, for an attacking team, would be of being in a stable state and attacking an unstable defence. The issue which we see so often is that a team seeking stability will often allow the defensive team to find stability. Equally, a team that tries to attack while a defence is unstable will often be in an unstable state themselves. There are teams which enter the box when the opposition defence is essentially stable, which is usually still dangerous, but the ‘value gap’ in these ‘entry’ stats gets wider when you take a step back to the final third, or to ‘progressive’ metrics.

The pass stats are worthy attempts at proxying danger, but there’s a risk that teams trip themselves up by chasing them.

But what is stability? A couple of past Opta Pro Forum presentations have touched on this - Mladen Sormaz and Dan Nichols investigating shape-disrupting runs (2020) and Guillaume Hacques looking at destabilising a set defence’s symmetry (2023). [the biggest race in football analytics is between ‘solving football’ and ‘establishing a central, easily-findable location for the history of the Opta Pro Forum’].

My current sticking point is finding a ‘stability’ definition which works for counter-attacks. If a team has been caught out by a ball over the top and is running back to its goal, chasing an opposition attacker, in perfect synchronisation, it’s not exactly ‘stable’. You could just say ‘look at pitch control’, but I suspect that, when facing set defences, instability often precedes the changes that pitch control would be detecting. It could be as simple as ‘stable systems don’t move quickly’.

A side effect of dwelling on ‘stability’ is what it would do to the metrics that come out of it. You’d probably end up with something like ‘how many times did a team create instability from a stable defence’… but that would leave open the possibility that a team racks up numbers by (unintentionally) allowing the opposition defence to get stable lots of times. Aiming for a ‘high percentage of stable defences rendered instable’ is not even necessarily a good goal.

The one downside of this focus on stability? It gives all the physics PhDs in football even more to do. Football isn’t played on a Newton meter.