Oldham Athletic: A Nearly-Half Term Report

Being a football fan is addictive. Being a data obsessed one is slightly reassuring, I find much of the time. You find out that these times and your club aren’t as unusual and unprecedented as you think they are.

For those that wish to moan about how bad it is, that can be annoying. You probably become a “happy clapper”, depending on the nature of your fellow supporters.

Either way, I thought I’d put together a graphic that charts where my team, Oldham Athletic are, as we enter the New Year. We’re not yet half way through the season, though we’re not far off — 21 of 46 matches have been played so far (plus one abandoned).

The raw record is won 8, drawn 3, lost 10. But it’s been a season of spells. The first few games were extremely worrying — losing 4 and drawing one of the first 5. Things have since got better — 8 wins, though the fact 6 of them have been on the road tells a story in itself.

The real question is: what patterns emerge in those matches — did Oldham do better than expected, or worse than, or some mix? Hence I did a bit of crunching the numbers.

I create Elo ratings for all football teams that start way back in the 1870s, and update for every match. It means I can easily look back at each match this season, the Elo ratings of each team and hence the Elo prediction.

We can think of the Elo prediction, between 0 and 1, as a measure, from Oldham’s perspective, of how difficult a match was going to be. For some fans, that’s an anathema — a team of Oldham’s history and stature should always be beating tiny teams that are up and coming and have money behind them. But if Oldham play a team with a higher Elo rating, then we should expect that that will be a tough match — regardless of the Football League history of that team.

Then if we give a 1 for a match Oldham won, a 0 for a loss, and 0.5 for a draw, we can measure how surprising the outcome was — surprise good (positive) or bad (negative). For example, when Oldham played at Exeter, Oldham’s Elo rating was 1037 and Exeter’s was 1132, and so the difficulty rating was 36.7 (closer to zero, more difficult, darker blue in the column after the team name in the table below). As Oldham won, the surprise was 1–0.367=0.63.

So, here’s the report card so far:

It’s colour coded, and in blue too. In the Difficulty column, a darker shade means more difficult (hence Bournemouth in the FA Cup, coming up, is by far our toughest match). Then on the rightmost column, Surprise, the deeper the blue, the better the surprise in our favour.

Hence the biggest positive surprise was winning at Exeter, with beating Cheltenham at home just behind that. The more pale, the more negatively surprising — hence that worrying opening to the season, losing to teams we shouldn’t have been expecting to lose to.

The two whitest Surprise entries since the opening five were Scunthorpe and Walsall at home — two matches that should have been won, really, given the form shown on the road.

So, what to expect? Well, the next few matches from the Difficulty column are pretty tough — which based on the last few months (since September) is a good thing. Perhaps we’ll carry on beating the better teams.

But we also have struggled in January the last three years, relative to December. In the last three Januarys Oldham’s record is W5 D5 L10.

Once we’ve been to Tranmere, things start to get lighter — relatively easier matches. But will we treat them that way, and get beat — as has happened a little too often this season?

I see three scenarios. One is that our record since September carries on, and we do well in the matches up to Tranmere (well, Carlisle really), and that will put is in mild play off contention, before (1) getting into play off contention by beating the teams lower down the table, or (2) tailing off against the teams lower down the table. The most worrying scenario is that our poor January form means we lose to the top teams, and carry on that poor form into the latter part of the season too. Let’s hope not…