By Joel A. Adejola in Analysis — Jan 19, 2025

Justified True Belief

Is anything consequential in sports?

This essay was first drafted on the 24th of November, 2024 after Arsenal's 3-0 win over Nottingham Forest.

Over the past few months, I spent some time away from football, spared from its chaos and relationships, which were built on a shared appreciation for the game.

I was troubled that I seemed to have an answer, opinion, or resolution to most issues relevant to me at that time: why Manchester United wasn't doing well; why a certain manager would get sacked; why a certain dynamic wasn't working; why another commentator was doing it all wrong; which player was more valuable to a team.

It made me consider whether any of my calls – and more broadly, the community's – were truly consequential. Here are some questions I pondered:

How precisely can we make predictions about sporting events?
What scale of predictions allows us the most precision?
- A team will win the league because...
- A team will lose a game because...
- A player will score in this game because...
If we cannot make precise calls, does that even matter?

So, some weeks ago, when Arsenal won on Ødegaard's return and broke their non-winning streak, my thoughts raced to one of the few football newsletters I'd allowed myself, The Transfer Flow Newsletter – and Kim McCauley's earlier newsletter about Ødegaard probably being '[Arsenal's] most important player'. Kim might've been onto something: I mean look at their eventual result against then competitive Nottingham Forest.

However, my current obsession is less about whether Ødegaard is or isn't Arsenal's most important player, but whether we can even ascertain that or any other discrete truth about sports. This essay is a prologue.

What next?

We'll talk about Ødegaard, but only after considering this something called Justified True Belief (JTB).

Here's a summary from James Somers' essay:

Epistemologists going back to the Greeks had debated what it meant to know something, and in the Enlightenment, a definition was settled upon: to know something is to have a justified true belief about it:

justified in the sense of deriving from evidence

true, because it doesn't make sense to "know" a falsehoood

belief, i.e., a proposition in your head

[Edmund] Gettier, in his tiny paper, upended the consensus. He asked "Is Justified True Belief Knowledge?" and offered three cases—soon to be known as "the Gettier cases"—that suggested you could have a JTB about something and yet still we would want to say you didn't know it.

Under this framework, to claim knowledge about 'Ødegaard being Arsenal's most important player,' we may need these three elements:

Belief – Ødegaard is Arsenal's most important player.
Justified – perhaps that Arsenal underperformed in games where Ødegaard did not feature AND that Arsenal underperformance was more prominent in games Ødegaard didn't feature compared to games where other players didn't feature.
True – perhaps a single, repeatable event like Arsenal's performance getting restored every time Ødegaard returned to the side.

The effort and analysis needed to synthesize this is difficult, murky and, some would argue, unnecessary.

However, sports culture demands that we – even if privately – frequently stake claims of knowledge. So how do we respond? We resort to easier, more discrete, and often epistemically weaker resolutions. Here's one:

Belief – Ødegaard is Arsenal's most important player.
Justified – During a run where Ødegaard did not feature, Arsenal did not win most games.
True – Arsenal win in Ødegaard's first game back.

So, what can we know?

I do believe there are simpler truths in sports.

Here's one: Any coach puts out a team they believe can win the game.

Here's why it's not so simple: Certain situations demand a coach to consider longer-term goals, player development, and politics when selecting the team.

Even without these exceptions, are we any better equipped to reliably and more precisely predict outcomes in sports? I don't know, but it is clearly an important and expensive consideration.

Recruitment. Outcomes of games. Trends in optimal strategy.