One term you will quickly come across if you ever decided to visit a statistically leaning site like FanGraphs, would be ‘regression to the mean’. I am no statistician so I apologize to anyone that is if the below is a bit simplistic, but, essentially, this means that over a period of time statistical anomalies will level out and a player will produce at a level in line with his talent and/or past performance. This doesn't mean that his future production will account for any past sub-par performance, but it will at least appear to improve to get back to the level he (or the league) usually performs.
Two things to note here. One, it is important to remember that while regression sounds like a negative term, it can go both ways. If a basketball player has a career free throw shooting percentage of 91% but starts a season 21 for his first 28 shots (75%), we would expect, over a longer period, that all else being equal, the average will regress back to his 91% level and so he should enjoy a period of shooting above his career average as things level off. Second, we are dealing with human beings and not robots so other factors do indeed play a role. A player might be unhappy with his contract, finding it hard to settle in a new rainy city (not looking at anyone in particular Carlos) or playing with an undisclosed injury, all of which will have some impact on his play. However, research done in the excellent Scorecasting suggests that ‘hot streaks’ are generally statistical quirks remembered due to our own desire to explain statistical fluctuations, rather than the result of a player being ‘locked in’.
If you've made it this far, we can get into the actual meat of the post. Taking all forwards who scored more than 5 goals last year, we see that, on average a player took 6.1 shots per goal with 2.9 of them on target. The correlation between total shots and goals is 89% while shots on target is even better at 91%. Taking shots on target a step further, we see that the standard deviation of the sample is just 0.78, suggesting that the shots/goal ratio holds up across the board. Indeed, of the 34 players to score 5 goals or more, 22 scored a goal every 2-3 shots on target and only three players (Drogba, Rodallega and Lovenkrands) had more than 4 on target per goal (Hernandez was the biggest outlier in the other direction, taking just 1.8 shots on target respectively to score).
So if we accept that a high number of shots on target is going to lead to a lot of goals (it sounds obvious but it isn't 100% correlated) then the idea is that we can look at the shot totals to date and if a player is scoring well below his career average rate, we could imply some regression coming in the future (the same goes for a player scoring every time he shoots).
The season so far
A few players stand out from the early going, though be careful here as we are in seriously small sample size range. This review will be more useful after a few more games, but it's worth taking a quick look now:
| Name | Goals | Total Shots | On Target | OT/G | Career Rate |
|---|---|---|---|---|---|
Dzeko | 6 | 14 | 10 | 1.7 | 2.6 |
Rooney | 5 | 16 | 10 | 2.0 | 3.4 |
Agüero | 3 | 9 | 4 | 1.3 | - |
Suárez | 2 | 6 | 3 | 1.5 | - |
van Persie | 1 | 7 | 5 | 5.0 | 2.9 |
Bent | 1 | 3 | 2 | 2.0 | 2.4 |
Gyan | 0 | 10 | 3 | - | 2.7 |
Carroll | 0 | 9 | 2 | - | 2.4 |
Torres | 0 | 4 | 2 | - | 2.4 |
Drogba | 0 | 5 | 1 | - | 3.1 |
While Dzeko and Rooney's goal rate looks unsustainable (and of course, Dzeko won't score twice a game all year) if they keep having the number of shots they've managed to date, they are going to score some seriously high totals. 10 shots a piece on target through 3 games is off the charts and not even the trigger happy Ronaldo could match those totals. This suggests that Dzeko deserves as much, or more hype than Aguero given his lower price tag and while Tevez is obviously there as a constant threat, Dzeko is not simply tapping in the good work of others.
You'd like to see Aguero and Suarez up there shots on target per game as they surely can't continue to basically score almost every time they hit the target. This pair are two of the most promising players in the league but this evidence does put at least a small blot on their developing resumes.
Though he hasn't racked up big totals on target yet, Gyan's 10 total shots stand out among those players without a goal and if he continues at that clip he will surely finish with a good haul come year end. Andy Carroll hasn't been well received this year but he too, with 9 shots in a couple of games, could be in line for some adjustment over the coming weeks.
For the future
As I say, this is more something to re-examine in GW8 or so but it is worth looking at nonetheless. The extreme totals produced by Rooney and Dzeko look like they could be legit and Dzeko is very much on my radar alongside Aguero for the coming weeks. We will check back on these totals in a few weeks.
I now have a full set of stats for the new season to work with, so keep checking back throughout the international break as we try and find some clues as to where this crazy season fantasy season is heading next.
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