Sunday, November 7, 2010

What Are The Most Common Scores in the Premier League?

What are the most common scores in soccer? Someone asked me the other day if I knew and I had to admit that I didn't. Well, I did conjecture, based on what we know from basic match facts, that the most common score lines involved something somewhere in the vicinity of fewer than three goals . But that's as far as it went; does this mean that 2-1 home teams wins were more likely than 3-0 ones, or whether 1-1 scores are as likely as 2-2 scores? I confess I really didn't know.

Take a look at Saturday's EPL scores for comparison:

Birmingham 2-2 West Ham
Blackburn 2-1 Wigan
Blackpool 2-2 Everton
Bolton 4-2 Tottenham
Fulham 1-1 Aston Villa
Man Utd 2-1 Wolverhampton
Sunderland 2-0 Stoke

These all seem perfectly "normal" or reasonable scores, don't they? But how common are they, once we compare them to many or all Saturdays in a season or across several?

Thankfully, my data archive allows me to make slightly more accurate statements about which scores are most common. Based on data for the last five years (the 2005/06-2009/10 seasons) I calculated the frequencies (in percentages) of various outcomes, listed by goals scored by home and away teams.

So what are the most and least common scores in the Premier League? To help orient readers, I've shaded outcomes that occurred more than 10% of the time yellow; outcomes that occurred with a frequency of between 5-10% of the time green; and outcomes that occurred between 2.5-5% of the time blue. For example, looking in the top left cell, we see that over the past five seasons, 8.74% of all Premier League matches ended in a 0-0 tie; moving one cell to the right, we see that 7.89% of matches ended in a 0-1 home loss, etc.

One thing to notice right off the bat is that there is quite a bit of variation across types of scores; they range from 0-0 to 9-1 and 8-0 to 0-5 and even 0-6. But these scores are not all equally likely to occur; instead, as the yellow cells show, 1-0 home wins and 1-1 ties are the most common scores in the Premiership.

At the same time, these score lines do not make up the majority of outcomes (as the slightly less than 3 goals per match average would suggest). Instead, these outcomes occur at a rate of slightly more than 10% of the time. Once we move beyond 1-0 home wins and ties at one goal a piece, scores tend to be clustered right around the 1-3 goal mark. In order of frequency, here are the Top 10 score lines in the EPL over the past five seasons:

1-0 (11.1%)
1-1 (10.6%)
2-1 (9.4%)
2-0 (9.1%)
0-0 (8.7%)
1-2 (5.8%)
3-1 (4.7%)
3-0 (4.4%)
2-2 (4.3%)
1-3 (2.4%)

Clearly, there are two groups of results: First, there is a group results that occur with a frequency of around 10% each (1-0, 1-1, 2-1, 2-0, 0-0), totaling fewer than 50% of matches. These five score lines never have the away team winning, and the home team never scores more than 2 goals. Second, there is a group of more mixed results that occur 5% of the time (1-2, 3-1, 3-0, 2-2), with both home and away teams scoring. And then there's everything else.

So looking back over Saturday's scores, the one that really stands out as unusual is Bolton's 4-2 win over Spurs. I hope Owen Coyle's squad know how truly unusual their success was - statistically speaking, that is.

Thanks to Don K.