Liverpool, Shots On Target, and The Top Four
Ahead of this week's Opta Pro forum, which I am very much looking forward to attending, I thought it would be interesting to revisit one of my favourite previous articles ('Better With The Ball? It's Just A Shot Away') which looked at the relationship between shots on target and success.
Has the trend that I discovered when looking at data fromĀ 2008/09 to 2012/13 continued this season, and what does this mean for Liverpool? Before we continue, a quick recap of my methodology and previous findings. I have compiled a statistic I refer to as TSoT%, which is the percentage of the shots on target in a match, or across a season, that a team has.
For a simple example, if a team has had sixty shots on target and allowed their opponents a total of forty, then their TSoT% is 60%.
Using this information, I was then able to plot the following graph:
As I noted in the original article, we can see that it broadly breaks down into four bands:
60% plus should see a team in the running for a top four finish.
50 ā 55% puts you in contention for a Europa League place.
Comfortably above 40% should see a team stay up.
Around 40% is relegation form.
Are these figures holding true this season? They are indeed, more or less.
The current top five in the Premier League all have a TSoT of 59.1% or better, the teams in sixth to ninth are between 54.4% and 58.3%, and the bottom three are all sub-40%. These three bands are almost exactly the same as the averages from the past four seasons, in fact.
As you can see, there isn't much difference between this and the actual league table, and that's despite the bottom half of the top flight being incredibly tight at present (with just six points separating the teams in eleventh and twentieth).
Only one team (Stoke City) are more than four places in the league table away from where their TSoT% ranking suggests they should be, and even allowing for them as an anomaly, the average rank difference is just 1.90. Bear in mind too that Stoke are only three points better off than the team in eighteenth, so they could easily finish closer to that position at the end of the season too. That said, it would be fair to assume that lots of the teams down there will also swap places, as the table is so congested.
No prediction model will ever be perfect, but this does seem to be a pretty effective one, and simple to compile too which is always a nice bonus. It could be improved by looking at where on the pitch the shots on target originate from, but I like that it can give a fairly accurate picture using limited data and without being particularly time-consuming to assemble.
It's fun to look for patterns and differences too. For example, we can see that the terms ranked third to fifth have very similar TSoT%s, but Liverpool have had more shots on target than the other two, at the expense of allowing more at the back too. Is attack the best form of defence, Brendan?
I'm also fascinated by the fact that Spurs and Newcastle are only separated by one shot on target, and only by one goal at either end of the pitch; that can't be coincidence?
It's interesting that Arsenal and Everton have an identical TSoT% (59.1%) and even an almost identical number of shots on target both for and against, yet the Gunners are ten points ahead of the Toffees; why?
Arsenal are better than the average rate of 30.2% at both ends of the pitch (with their opponents converting the lowest proportion of their shots on target in the division) whereas Everton are only above par at the back, with only six teams converting a lower proportion of their on target efforts going forward. I think that shot location data can help to explain the conversion differences, but I'll leave that to the experts (such asĀ Colin Trainor).
ButĀ what does this all mean for Liverpool? Brendan Rodgers' record with shots on target has ranged from the sublime to the ridiculous at both ends of the pitch in 2013/14, so it may be hard to tell.
For instance, the Reds prevented Hull City from having any shots on target at Anfield this season, and perhaps more impressively did likewise at White Hart Lane. To give a little context to what an impressive achievement that is, an opposition shot on target shutout has only happened seven times inĀ Liverpool's 214 league games since the start of 2008/09.
However, the 'Pool also allowed Everton to have twelve shots on target at Goodison Park, which is the most by any Liverpool opponent over the aforementioned period.
Similarly, the Reds only had one shot on target at Villa Park, but twelve at home to Norwich City, which was the sixth most in the last 214 league matches. This variance in different matches means that the Reds have had a TSoT% between 25% and 100% in various games this season.
As this article is a review of TSoT% for whole campaigns, let's take a look at how Liverpool's figure for this has fluctuated as the season has progressed. Remember that 60% is the target mark for a top four side.
The sample is large enough now to ensure that it shouldn't fluctuate wildly from here on in. Assuming that this is the case, then Liverpool should be able to maintain a challenge for a top four place over the remaining fourteen games. Kopites should try to remember this the next time a disappointing result occurs, as it demonstrates that overall Liverpool are on the right track.
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Please check outĀ my other articles, and follow me onĀ Twitter, Facebook or LinkedIn. Thanks.