Saturday 21 November 2015

Everyone Loves Ricky.

Everyone loves an individual goal. Be it Peter Beagrie beating six players (or the same player six times) in the late 80's to John Barnes in the Maracana and Ricky Villa lighting up the old Wembley Stadium.

It may be a trick of the mind, but such unassisted goals also seem to have an air of inevitability. Once the last line of defence is reached the keeper rarely spoils the party.

There may be legitimate reason for this impression. A player who has largely created his own chance has often disrupted any defensive organisation that had previously existed, while being fully in control of the ball, rather than stretching to master an over hit assist.

While imperfect, the absence of an assist in an attempt description might serve to identify goals or shots that were a result of individual skills, rather than a chance created through a series of team based passes.

Using a season's worth of shot data from open play, it does appear that unassisted goal attempts result in scores at a higher rate than attempts originating from an assist. This may have occurred by chance, but the analysis strongly suggests otherwise.

A Spurs legend dreams of historical deeds.
As a baseline figure using single season data, once location is accounted for, an unassisted on goal attempt is around 10% more likely to be scored than an attempt that came about by a teammate setting up the chance.

This has implications for both teams and players who may be adept at creating potentially better quality chances through individual effort compared to relying more on a teamwork based approach, where the opposition may be able to defend more cohesively.

In 2012/13 only 15% of Arsenal's on goal attempts from open play were lone wolf attempts compared to 25% for Sunderland. However, variation of percentages should be expected, even if all teams have broadly the same propensity to create individually crafted chances.

Premier League attacks, based on the limited data I have, do created widely different numbers of chances from open play, (Arsenal created almost twice the number for Sunderland) and within these chances are varying proportions of individually created chances.

However, the spread in 2012/13 was insufficient to conclude that Sunderland's higher proportion of individually created chances compared to say Arsenal, is a real trait that may persist. It could be, but more data is needed.

The same could not be said for Premier League defences in 2012/13. The league average was for 20% of open play chances faced to be predominately the product of an individuals efforts. But this fell to 9% for Reading's defence to a high of 29 for Arsenal.

This time the spread could not be explained away as merely random variation. At the very least for that season, opponents seemed to be attacking certain sides in a variety of biased approaches from open play.

The quantity of chances faced will always overwhelm any persistent bias in the type of chance allowed, but identifying if and perhaps why a side is allowing a larger percentage of individually created chances, that may carry a greater sting in the tail, may make for marginal gains.

Also individuals, who aren't called Messi or Ronaldo, may be unfairly define as having a lucky season, when they are actually rather good at persistently emulating Ricardo Julio Villa.

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