Premier League combatants possess similar abilities

Two points separated six teams at the bottom of the Premier League before the weekend. The gap is now five points but could narrow again. Reading upward, the bottom six are Sunderland, Crystal Palace, Hull, Leicester, Middlesbrough and Swansea.

They are the teams most likely to finish in the bottom three and be relegated, but only because they are in the lower part of the table today – not because they are worse than many of the teams above them.

This season, as in other seasons, there is not much difference in ability between most teams in the Premier League. Differences in results between them owe little more to differences in skill than the outcome of a coin-tossing competition.

Some people get offended when I say this. To them it sounds like I am saying that matches between these teams are decided mostly by luck and hardly any skill is involved. I am saying one thing, but not the other.

Skill is involved, considerable skill, but similar skill. When two sporting competitors have similar skill the result of a contest between them cannot be decided by skill – they have similar skill. It must be decided by something else. And that something else, for want of a better understanding, we call luck.

Imagine a sport in which the best two competitors were so good they were almost perfect, but identically almost perfect.

A contest between them would be thrilling to watch, a never-to-be-forgotten example of how well that sport can be played. But the result would not be determined by a difference in skill – there is no difference in skill. It would come down to a moment of luck.

Skill can be the deciding factor only when competitors have different skills.

The first graph above illustrates why I believe that most seasons there is little difference in ability between most teams in the Premier League.

The numbers along the bottom represent positions in the table after the first 19 games of a season. The numbers up the side represent average points gained in the last 19 games of a season. The graph covers 21 seasons, all those since the Premier League expanded to 20 teams.

If differences in position after the first half of a season were attributable mostly to differences in skill, there would be differences in results over the second half of a season as well. For the top six or seven teams there were. For most of the others there were not.

Some teams in last place were cut off and cast further adrift with every round of fixtures played – Aston Villa last season, for example, and Derby eight seasons earlier. For teams in positions eight to 19 after the first half of a season there was hardly any difference in average points gained in the second half of a season.

Over the first half of a season the average gap between eight and 19th places was 13 points. Over the second half of a season, teams who had been eighth averaged 22 points and teams who had been 19th averaged 21 points.

A competitor who finished bottom of a coin-tossing league could moan that they were no worse than all the competitors above them. Many teams relegated from the Premier League could wail a similar lament, one only slightly less sweeping. Many teams demoted from the Premier League are no worse than many teams who are not.

Group victors enjoy greater success

Champions League group results, perhaps surprisingly, give a reasonable indication of how well teams will do in the knockout rounds. I say perhaps surprisingly because a group consists of only six games, home and away to three opponents, who can vary widely in quality.

Nonetheless the better a team fare in their group the further they are likely to progress in the knockout rounds.

I looked at records in the group stage and knockout rounds from the last 13 Champions League seasons, all those since the present format was adopted.

To quantify progress in the knockout rounds I called winners 1, runners-up 2, beaten semi-finalists 3.5 (because they could be said to have finished third or fourth), beaten quarter-finalists 6.5 (halfway between fifth and eighth) and round-of-16 losers 12.5 (midway between ninth and 16th).

The more points a team gained in their group the further they were likely to progress in the knockout rounds, as you can see on the second graph above.

The numbers along the bottom represent points gained in a group. The numbers up the side represent average finishing position in the knockout rounds. Lower finishing positions are better and the graph slopes downward.

A big influence on achievement in the knockout rounds was whether a team qualified from their group in first place or second. In the round of 16, group winners play group runners-up (who tend to have qualified with fewer points and be weaker) and the second leg is at home.

The average finishing position in the knockout rounds of group winners was 6.6. The average finishing position in the knockout rounds of group runners-up was 10.4.

Over 13 seasons there were 104 group winners and 104 group runners-up. Ten of the teams who topped their group won the Champions League – a strike rate of nearly ten per cent. Only three of the teams who finished second in their group won the Champions League – a strike rate of less than three per cent.