Diminishing returns | Analysis of 'shots on target' data

Diminishing returns | Analysis of 'shots on target' data

Shots on target data (SOT) is now easily accessed, so it can be of interest when analyzing how good a team is.

One way of looking at the strengths and weaknesses of a team is to give a value to the attack and the defense respecitvely. This can be done using SOT analysis.

There are obviously other variables, such as motivation and injury, but SOT provides a very good starting point. In simple terms, it allows us to give a value  to the attack and the defense of any team and compare that to the value of their opposition. This allows us to anticipate some features of their match-up.

For example, we might want to find a value bet for a game in which Man Utd are playing at home to Man City. Firstly, we’d probably like to work out the probability of either team winning.

We need to find the value of the defense and attack for each team and work out the expectancy of the number of goals that Man Utd and Man City will score.

Man Utd’s goal to SOT ratio is 0.45, as you can see in the table below. Their average number of SOT per game is 5.8.

If you were to multiply 0.45 by 5.8 then you have a value of 2.61 goals. Sadly, though, it is not that simple.

In this hypothetical example:

  1. Rooney is injured
  2. Man United are playing in the European Cup Final the week after
  3. Manchester United have already won the league
  4. Kompany is injured (the strength of the opposition’s defense is subject to a number of other variables, too)

After taking all the above into consideration, I came up with the following hypothetical values:

  1. Expected shots on target for Man Utd: 4.33; Expected shots on target for Man City: 6.14
  2. Expected goal to SOT ratio for Man Utd: 0.27; Man City: 0.23

If we multiply 0.27 by 4.33 for Man Utd, we see in this hypothetical example that they are expected to score 1.16 goals

Man City in this hypothetical example are expected to score 0.23 times 6.14, so 1.412 goals.

As Man Utd, on paper, should be less motivated for this game, we would look to have a bet on Manchester City, if we can get value.

Looking in more detail at the table below we see that Sunderland have the best Goal to SOT ratio at 0.46. Steven Fletcher has scored 5 goals and had 8 shots on target, so his goal to SOT average is an impressive 0.625.

By comparison, Robin van Persie has had 16 shots on target and has scored 8 goals, so he boasts a 0.5 average, though in a much more creative team.

Carlos Tevez appears in the top 10 in terms of shots, with 34. But if we look in detail, he has 14 shots on target, and just 4 goals. This means that Tevez has a goals to SOT average of just 0.28.

QPR have the wost goal to SOT ratio in the Premiership and Norwich the second worst, with 0.18 and 0.2 respectively.

QPR are certainly shooting too much outside the box. Meanwhile, Grant Holt for Norwich has had 7 shots on target and scored 3 goals, so he has a ratio of 0.42. The problem is that there are no creative players around Holt to help him out, with only Hoolahan contributing more then 100 completed Final Third Passes.

Another interesting insight pertains to Wigan. Before you back them to be relegated on the basis of this data, last season Wigan had the worst goal to SOT data for most of the season, only to escape the bottom three in dramatic style.

The average goal to SOT ratio in the Premiership currently stands at 0.31. You can identify during a game if a team are having an average game by checking the shots on target.

With the millions that Man City have spent on forwards, and a collective  ratio of 0.28, below the league average, we might expect more bang for buck than the stats at present indicate.

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