The Suarez and Sturridge SAS SOT Diff

How do the Premier League’s deadliest striking duo’s Shots on Target measure up to their expectations and each other?

They make a great couple don’t they? The Premier League’s resident sociopath and the young tearaway who seemed incapable of settling down. A recipe for disaster has somehow become one of the most potent goal scoring combinations in European football, get the right screenwriter on it and we’ll have ‘em weeping in the aisles come next years Oscar nominations.

And there have been twists and turns along the way; the hand of fate has conspired against the Suarez-Sturridge Connection (because the SAS is the worst kind of unimaginative football media BS) this season. On several occasions they have been torn apart only to inevitably find each other once again, consummating their reunion with a whirlwind of attacking football.

A poetic tale indeed but what are the finer points of the plot? What do the stats say about our two protagonists? Can one live without the other, do they work better alone? Following on from our SOT Diff work on Olivier Giroud, let’s see what we can learn about Suarridge (?)

Daniel Sturridge SOT Diff at Anfield

A player’s SOT Diff is the number of Shots on Target he managed in a match subtracted by the number of Shots on Target he was expected to achieve. If you want to know the details of how the expected number of SOTs is worked out, have a look at the last piece on Olivier Giroud ( ). Below are the SOT Diffs for Liverpool and Sturridge  in the home games he has been a part of:

Sturridge is compiling a nice little home record. Of the eight games at Anfield he has been a part of the Englishman has scored 7 times. On average he is surpassing his expected Shots on Target by about 1 per game. He is expected to average out at 1 SOT pg but is actually operating closer to 2 per game. His average number of Shots per Game is 4.5 meaning he is gets near on 50% of his Shots on Target.

The one concern for Sturridge would be that he isn’t appearing to have the same kind of impact in the harder games at Anfield. He broke even against Man Utd and under-performed against Southampton, interestingly this was the case for Liverpool aswell and Suarez was not available for either of these games.

Daniel Sturridge SOT Diff Away

Sturridge’s numbers aren’t  much different away suggesting he has operated on the same level of form wherever he has played this season. Outside of Anfield he has a very similar goal rate scoring 6 in 7 and is again exceeding his SOT expectations by over 1 per game. With this extra SOT pg he is regularly hitting the target twice each time he plays away bringing his shooting accuracy up to around 75% on the road. Impressively, he has achieved this even against some of the harder opponents exceeding expectations at Swansea, Everton and Arsenal.

At this point we would look to analyse Sturridge’s SOT Diff in the games where Liverpool were expected to have less than their average SOTs but due to injury he has missed the great majority of these matches. We already know that he over-performed against Everton and Arsenal but his absence in the games against Spurs, Hull, Man City and Chelsea mean we can’t be sure how effective he is against tough opposition.

Liverpool and Sturridge SOT Diff Comparison

This is the SOT Diff of Liverpool (as a team) and Sturridge for every game this season that he has played in. Here are the numbers:

And here are the bouncing balls. The idea is to see how often the two move in the same direction – this shows a correlation between Liverpool and Sturridge:

made with ChartBoot

The idea of this is to see whether we can say that Sturridge’s SOTs have some form of effect on Liverpool’s team SOTs in any given match. Here is one more chart, a combo chart, to help us draw some conclusions. The bars are Liverpool’s SOT Diff and the line is Sturridge’s:

All in all, Sturridge does pretty well by Liverpool. We already know that Sturridge generally exceeds his expectations and on 7 occasions both Liverpool and Sturridge have over-performed together. Plus on a couple of occassions Sturridge’s efforts above and beyond have helped keep Liverpool on an even keel.

However, we are not talking complete symbiosis- there have been several divergences between the two over the course of the season. And more interestingly both Liverpool and Sturridge started to attain more extreme differences after the Southmpton game. It was like something was missing up to that point, but what could that have been?

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Luis Suarez SOT Diff at Anfield

From 9 appearances and 29 SOTs so far this season, Suarez has netted 16 times at Anfield – a stunning record but one that should be contextualised. First, the up side. Generally speaking, Suarez is expected to get 2 SOTs per home game and generally speaking he has made a fool of this expectation. Given his average SOT Diff record he is actually hitting the target about 3.4 times per game. And considering that he is getting on average 6.3 shots per game his Shot Accuracy is about 54 % – slightly higher than Daniel Sturridge.  This is awe-inspiring stuff. But there is a slight downside.

Look at the games where Suarez has achieved big SOT Diffs, then look at the teams he has got them against. Five relegation contenders, and an off-kilter Everton. Meanwhile he has also underperformed against moderatley hard opposition in the forms of Hull and Villa. Is there a weakness to the Uruguayan goal-machine?

Luis Suarez SOT Diff Away

The Suarez SOT Diff picture away from home isn’t as pretty as you may think. He has scored 7 goals in 9 appearance with 22 SOTs to his name. And whilst he commands a 63% shooting accuracy on the road and is still exceeding his expected SOT Diff, it is by 0.89 – less than an extra SOT per game, which is not as good as Sturridge. What’s worse is that if you take away his clinical dissection of an ill-managed Spurs side, that number drops to 0.4 and then we are talking Giroud numbers.

Luis Suarez SOT Diff vs Hardest Opponents

We mustn’t be quick to ignore Suarez’s dismantling of Spurs. It may have been one of Tottenham’s worst displays of the season and the final nail in AVB’s coffin but to get 7 SOTs away from home against any Premier League team is a mighty feat. That being said, if we were to discount this one result suddenly it looks like Luis Suarez has performed decidedly averagely in front of goal in the hardest matches this season.

He has consistently met his expectation of 2 SOTs per game but considering how much that number has been dwarfed in other fixtures, might we be inclined to think Suarez could have done better than he did against the likes of Chelsea and City? Consider the fact that he failed to score against those two as well as against Arsenal and Hull.

Liverpool and Suarez SOT Diff Comparison

Here are the Numbers, Bouncing Balls and a Line Graph – Note I have kept in the first five Liverpool fixtures of the season, which Suarez did not play in:


made with ChartBoot


Correlation!! This is the true power of Luis Suarez, his ability to seemingly single-handedly dictate the SOT Diff performance of Liverpool. That is a slight exaggeration but look at the similarities in the line graph from the Everton away game and onwards. When Suarez does well, Liverpool do well. When Suarez under-performs, Liverpool are average.

Careful now, we only have a handful of data points so we shouldn’t be drawing any harsh conclusions. Still though, compared to Sturridge’s graph, Liverpool do appear to be more reliant on Suarez. On top of that, compare the heights of Liverpool’s SOT Diff in the first 5 games of the season when Suarez was unavailable to everything after that.

Liverpool seem to be reliant on Luis Suarez. There are the goals he scores, the assists he makes, the chances he creates, the passes, the seemingly unyielding engine that drives him. Then there are the intangibles – the influence on his teammates, the galvanising spirit he seems to bring to the Liverpool changing room. But rarely is dependence a good thing. Have Liverpool become too reliant on Suarez? What happens to his team and his strike partner when he isn’t around?

Effects of Suarez and Sturridge on Each Other and on Liverpool

Three Bouncing Balls and a line graph for your consideration showing the SOT Diffs of Suarez, Sturridge and Liverpool:


What exactly are we seeing here? Let’ s start with Suarez and Sturridge, these are their average SOT Diffs when playing alone and when playing with each other:

It appears that Sturridge needs Suarez – he is like a different player when the Uruguayan is behind him. But the relationship is not reciprocal, Suarez has less SOTs when sharing the forward role. At first glance, it looks like Liverpool will be okay as long as Suarez is involved in some way – he’ll dwarf his average if playing alone or he will help Sturridge exceed his whilst still over-performing. Win-win, right? Let’s have a look at Liverpool’s SOT Diff as a team when playing with either one of their forwards or both.

Of course we are only going on half a seasons-worth of data but it looks like bad news for Daniel Sturridge. Liverpool’s SOT Diff is close to zero when he plays upfront alone and even when he plays alongside Suarez, his team don’t do as well as when his partner is the solo striker. From this angle Sturridge is the personification of the third wheel…

Game States

… but that is only one angle. And herein lies the danger of using stats. Although they are a good indicator of performance I would happily trade 2 SOTs for 1 goal any day of the week -especially one that brings my team back from a losing position or one that puts them into the lead. This is the point of game states, in a way it measures the importance of a goal, obviously a goal when a team is one down is more important than when they are 2 or 3 goals up. Here are the goals Sturridge and Suarez have scored in each of Liverpool’s Game States this season:

Suarez loves putting the icing on the cake. The majority of goals he has scored this season have come when Liverpool were already in the lead. Of course, such goals are not without merit. The 5 goals he scored when Liverpool were only 1 goal up probably cemented their victories, and at the end of the season who knows how important the bonus goals will be when Goal Difference can decide European qualification. Still, I would argue that Sturridge’s goals have been more important. He has fired Liverpool into the lead only one time less than Suarez and on several occasions has done what Suarez is yet to do – get them out of losing positions.

Conclusion

What are we left with if not a Hollywood ending? Two loners that find strength in each other to the benefit of the greater good. One of lesser skill who attains new levels under the stewardship of his partner. The other – a man of tremendous ability who has found a way to give back to the club that has faithfully stayed by his side whilst still staying true to himself. Someone pass me a tissue, this is too much.

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