The Reep Fallacy

There have been long-standing “artisan-vs-artist” debates over how the “the beautiful game” (i.e. football/soccer) should be played. In his history of tactics in football, Wilson (Inverting the Pyramid, 2008) characterised tactical debates as involving two interlinked tensions – aesthetics vs results and technique vs physique. Tactical debates in football have often focused on the relative merits of direct play and possession play. And the early developments in soccer analytics pioneered by Charles Reep were closely aligned with support for direct play (i.e. “the long-ball game”).

Charles Reep (1904 – 2002) trained as an accountant and joined the RAF, reaching the rank of Wing Commander. He said that his interest in football tactics began after attending a talk in 1933 by Arsenal’s captain, Charlie Jones. Reep developed his own notational system for football in the early 1950s. His first direct involvement with a football club was as part-time advisor to Brentford in spring 1951, helping them to avoid relegation from Division 1. (And, of course, these days Brentford are still pioneering the use of data analytics to thrive in the English Premier League on a relatively small budget.) Reep’s key finding was that most goals are scored from fewer than three passes. His work subsequently attracted the interest of Stan Cullis, manager in the 1950s of a very successful Wolves team. Reep published a paper (jointly authored with Benjamin) on the statistical analysis of passing and goals scored in 1968. He analysed nearly 2,500 games during his lifetime.

In their 1968 paper, Reep and Benjamin analysed 578 matches, mainly in Football League Division 1 and World Cup Finals between 1953 and 1967. They reported five key findings:

• 91.5% of passing sequences have 3 completed passes or less
• 50% of goals come from moves starting in the shooting area
• 50% of shooting-area origin attacks come from regained possessions
• 50% of goals conceded come from own-half breakdowns
• On average, one goal is scored for every 10 shots at goal

Reep published another paper in 1971 on the relationship between shots, goals and passing sequences that excluded shots and goals that were not generated from a passing sequence. These results confirmed his earlier analysis with passing sequences of 1 – 4 passes accounted for 87.6% of shots and 87.0% of goals scored. The tactical implications of Reep’s analysis seemed very clear – direct play with few passes is the most efficient way of scoring goals. Reep’s analysis was very influential. It was taken up by Charles Hughes, FA Director of Coaching and Education, who later conducted similar data analysis to that of Reep with similar results (but never acknowledged his intellectual debt to Reep). On the basis of his analysis, Hughes advocated sustained direct play to create an increased number of shooting opportunities.

Reep’s analysis was re-examined by two leading professors of performance analysis, Mike Hughes and Ian Franks, in a paper published in 2005. Hughes and Franks analysed 116 matches from the 1990 and 1994 World Cup Finals. They accepted Reep’s findings that around 80% of goals scored result from passing sequences of three passes or less. However, they disagreed with Reep’s interpretation of this empirical regularity as support for the efficacy of a direct style of play. They argued that it is important to take account of the frequency of different lengths of passing sequences as well as the frequency of goals scored from different lengths of passing sequences. Quite simply, since most passing sequences have fewer than five passes, it is no surprise that most goals are scored from passing sequences with fewer than five passes. I call this the “Reep fallacy” of only considering successful outcomes and ignoring unsuccessful outcomes. It is surprising how often in different walks of life people commit a similar fallacy by drawing conclusions from evidence of successful outcomes while ignoring the evidence of unsuccessful outcomes. Common sense should tell us that there is a real possibility of biased conclusions when you consider only biased evidence. Indeed Hughes and Franks found a tendency for scoring rates to increase as passing sequences get longer with the highest scoring rate (measured as goals per 1,000 possessions) occurring in passing sequences with six passes. Hughes and Franks also found that longer passing sequences (i.e. possession play) tend to produce more shots at goal but conversion rates (shots-goals ratio) are better for shorter passing sequences (i.e. direct play). However, the more successful teams are better able to retain possession with more longer passing sequences and better-than-average conversion rates.

Reep remains a controversial figure in tactical analysis because of his advocacy of long-ball tactics. His interpretation of the relationship between the length of passing sequences and goals scored has been shown to be flawed, what I call the Reep fallacy of analysing only successful outcomes. Reep’s legacy to sports analytics is partly negative because of its association with a very formulaic approach to tactics. But Reep’s legacy is also positive. He was the first to develop a notational system for football and to demonstrate the possibilities for statistical analysis in football. And, crucially, Reep showed how analytics could be successfully employed by teams to improve sporting performance.