Football by Numbers
Many moons ago, as a trainee odds-compiler for one of the UK’s biggest firms, I remember our then head-of-football teaching me a very simple and quick technique for pricing up pre-match 1X2 markets.
Simple and very effective – the method was largely to remove the home-bias from the equation, and ask yourself “who would be favourite on a neutral venue?”
In general, for most top divisions, the home side wins around 44% of the time. A 5/4 shot in other words. So if two teams are of equal ability, we’d price up the home team as a 5/4 chance (before margin is applied). Draw’s account for around 26% of results (11/4 before margin), while away wins are around 30% - a 9/4 shot. Basically it gives us a very good starting point to work from.
This was indeed a terrific point of reference to work from, and quite effective given that most top divisions post relatively similar numbers.
However, it’s worth reminding ourselves that not all leagues were made equal , and using this starting point isn’t always a winning strategy. Which leagues see more goals? (and is it statistically significant?). Which leagues enjoy a great home / away bias? Are some leagues less likely to see draws?
Home Win % and Draws
Let's start with home wins. Taking data from this season and last season (and adding a further year to the MLS given their season has only just begun), we see the following trends for home wins:
Top The top divisions are marked in Red, Tier 2 in Orange, and those considered below at Blue.
First it's worth nothing with the top two bands, with only two exceptions, every league records a home win % between 42.9% and 49.1%. The exceptions are Bundesliga 2 and MLS. The former can potentially be explained away as not being quite as strong as the remainder in the group, while MLS is a particular case in point.
MLS teams still travel large distances for away games, and are still relatively inexperienced at handling the demands this places. This is often a good angle, as bookmakers still often fail to consider this aspect sufficiently.
Draw Scarcity
Secondly, we should note how draws change. In top flight leagues, the draw is typically expected around 25-26% of the time. This remains pretty static in the second tier leagues as well.
Dropping down the quality of league however, a glance at the English Regional step and below (National League N/S and below) and adding in Scottish Leagues 1 and 2 reveals an interesting pattern. We notice a substantial drop in draw likelihood - all the way down to 21%.
That's certainly important enough that we need to factor it into our betting on Match Results for sure (and may well be one of the reasons bookmakers often struggle to win at this level of competition)
We should also wonder WHY the draws become more scarce - and the answer is in fact fairly obvious. Here is a table adding in average goals against the previous data.
We see a decent correlation between high goals (i.e. ill disciplined defenses and lack of organisation) and fewer draws. This makes complete sense when using any football model or distribution. Shown another way, here we have a correlation graph.
Note the weaker leagues (highlighted in yellow) tend towards the highest average goals per game, and towards the fewest draws.
I was hoping to reach some sort of conclusion, but it kind of feels we've got there already. In essence, every league is different. Cultural influences on football can affect how leagues are played around the world, but when betting, you should typically expect more goals in lower quality leagues, fewer draws, whilst you should consider US MLS as a bit of a weird out layer and consider it a unique case.
Hope you found this train ride waffle at least a little interesting!