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HOT TOPICS: Fixture Strength Could Doom the Trotters

Fixture strength a review

This is something that is forever overlooked by everyone at the start of the season. Playing away to Manchester United, Chelsea and Arsenal in your first five games, surely has a big effect on how many points you are going to have won - whatever quality your club has. To quantify this we used our overall adjusted estimated points performance averages for each team (home and away) to get a percentage figure above or below average for each clubs set of fixtures over the first five and ten games of the season. For example, in playing home to Aston Villa, away to Man City, home to Middlesbrough, away to Manchester United and home to Sheffield United, Arsenal had a fixture strengthen in their first five games 2.9% easier than average. 

Having established a measure for fixture strength we then used correlation coefficients to determine the strength of the relationship that existed between the strength of a clubs fixtures and the number of points they won over the first five and first ten games of the season. Correlation coefficients are a statistical method to measure how closely associated two statistics are, on a scale of 1 to -1. A correlation approaching 1 means the two variables are very closely positively related. That means that an increase in one means there is an increase in the other. A correlation approaching -1 means the two variables are closely related but in opposition. An increase in one is associated with a decrease in the other. If the correlation between two variable approaches zero, however, there is no statistical relationship what-so-ever, and a change in one variable tells us nothing about a change in the other, and vice versa.

We discovered that the correlation coefficients between a team’s points won and fixture strength in the first five and ten games were -0.70 and -0.66, respectively. This indicated that a strong negative relationship existed between the two and using regression analysis this relationship was shown to be significant for both the first five and first ten games of the season. Therefore we were able to draw a definitive conclusion that the harder the fixtures the less points a team is likely to win to begin a season.

Fixture strength in the run-in.

Using the same method as described above to establish fixture strength we looked back at last year’s Premier League run-in to establish whether the strength of a team’s fixtures had a significant bearing on how a teams finished a year ago. What we found was that the correlation between a team’s fixtures with ten games to go and how many points they won was almost zero (0.08) indicating that over the last ten games of last season fixture strength had very little impact on how a team finished. However, with five games to go the negative relationship resurfaced (-0.20) but nowhere near to the strength witnessed to begin the season. It was however, just significant at the 10% level, meaning that there is a 90% chance that the relationship is true and not occurring due to chance alone.   

Investigating this further it appears that the only ten game period in which the strength of a teams’ fixtures has a significant effect is the first ten games of the season. The main reason for this is that over a ten game period the difference in fixture strength from one team to the next is not vast – on average the difference is about 20% between the easiest and hardest fixture lists. Over a five game period this difference rises to a mean of 52%, indicating that over a smaller sample of games the strength of opposition can vary greatly between teams and thus have a greater effect on the number of points won. Why the first ten games are different has a lot to do with other factors as investigated in last years book such as the integration of new players (which we also found to have a significantly negative effect to begin a season) and new coaches.

Now that we know that fixture strength does have a negative effect at the end of the season and that all clubs have under ten games remaining we can have a look at the strength of each clubs remaining fixtures to give us and indication of what might transcend before the end of the season (Table 1.1).