Friday, 1 June 2012

Strikers Shouldn't Be Afraid To Miss.An Appreciation of Robin van Persie.

As the seasons draw to a close across Europe the process begins of evaluating players for end of year awards or as potential transfer targets during the next transfer window.Inevitably the main spotlight falls on attacking players and goalscorers and the way in which these type of positions are judged is gradually changing as a result of the availability of more extensive data.Where there was once simply goals scored and games played anyone can now access more informative granular data such as shots,shots on target and shots to goals ratios.

Excellence in any form rarely requires numerical verification,so it seems sensible to start with the acknowledged best and review their statistics in an attempt to spot any indicators of potential greatness.Each of the top clubs possess fine strikers,but as this year has demonstrated,few are better than Arsenal's Robin van Persie and he was equally impressive last season when he scored 18 times at a rate of almost a goal per starting appearance.I'm going to use van Persie's scoring statistics from 2010/11 when he contributed 18 Premiership goals to Arsenal's seasonal total of 72 using data kindly provided by OptaPro.

Van Persie made 25 appearances in the Premiership for Arsenal in 2010/11,including six from the bench.His 18 goals came from 85 attempts on goal,neglecting 12 blocked efforts,so his strike rate was an impressive 21%.Of his 85 attempts,43 either ended up in the back of the net or required the keeper to make a save,so his accuracy of 50.5% was equally noteworthy.

If we compare van Persie's shooting a scoring prowess to his fellow Arsenal strikers and midfielders,including the likes of Fabregas,Arshavin,Nasri and Walcott we find that he leads his teammates in both categories.The rest of the team minus the defenders hit the target with just 49% of their combined attempts and scored only 13.3% of the time.

Van Persie's Shooting and Scoring Efficiency Compared to that of his Fellow Midfielders and Strikers.

% of Shots
on Target.
% of Shots
that Resulted in Goals.
Robin van
50.6 21.2
Arsenal's Other Midfielders & Strikers. 49.1 13.3

We shouldn't really be surprised at these figures,Robin van Persie is primarily a goalscorer and a big part of that talent is an ability to convert chances.Combined with his superior accuracy,he appears to possess the classic requirements to be a top striker,namely an ability to hit the target and lethal finishing.However,these raw numbers may be deceiving and with further investigation another less obvious and potentially important facet of van Persie's talent and personality may become apparent.

Nearly a quarter of van Persie's goal attempts were made from a distance of ten yards or less compared to just 16% of those attempted by the other Arsenal players and it seems reasonable to assume that hitting the target in a fluid sport such as football becomes more difficult the further away you are from goal.Using OptaPro's 2010/11 seasonal shooting data for van Persie and his colleagues I've used regression analysis to project how likely it is that each group firstly scores and secondly hits the target from varying distances.

How Likely Arsenal Were to Score from Varying Distances Based on 2010//11 OptaPro Data.

The data is quite naturally sparse as we move further from the goal and the line of best fit is only a approximation,but van Persie's preeminence amongst his team as a prolific converter of chances is confirmed.His projected conversion rate is superior for the entire range of distances from the penalty area and beyond.If goalscoring is a talent,this graphic demonstrates that van Persie certainly possess it and given the choice of a chance falling to either him or a another random Arsenal player,van Persie should be the choice.

Again this merely confirms RvP is an excellent striker and we already knew that,but the second graphic may go someway to shedding new light on how he is so successful.A large proportion of van Persie's goal attempts are made close to the goal,25% are within ten yards and the closer you are to a target the easier it is to hit it.If we run another regression on how likely it is a shot will hit the target with varying distance,we see that van Persie is actually less accurate than his teammates at most shot distances.His overall superior accuracy of 50.6% compared 49.1% that we saw in the first table results from his shots on average originating from closer to the goal than those attempts from other Arsenal players.

How Likely Arsenal Were to Hit the Target from Varying Distances Based on 2010//11 OptaPro Data.

So now as an Arsenal fan if you want to see the opposing keeper have to attempt a save you are slightly better off if the chance falls to a random Arsenal attacker or midfielder rather than the team's consistent leading scorer.

These results are from one season and just one team,so they may not be repeated over other seasons or in larger sample sizes,but potentially we have a tremendously talented striker who is better than his teammates at converting chances regardless of shot distance.However,he is also more likely to miss the target completely than are a group of comparable colleagues at all distances until the rates converge around 30 yards from goal.

One of the qualities that former England coach Sven Goran Eriksson looked for in his players was an absence of fear of failure and perhaps the numbers we are seeing here shows that van Persie has this trait.His "poorer" accuracy at all distances compared to his colleagues may be because he is prepared to shoot early or aim for the areas of the goal where the margins for error are small.His more conservative teammates may be inclined to play safer and be content to initially force the goalie to make a save.Van Persie's longterm payoff from being free of any anxiety caused by an increased "failure" rate for accuracy may be an increased successful goal conversion rate because his on target shots are more difficult to anticipate or save.

We are conditioned to look at performance indicators and assume that increases in efficiency is always the way to go,but perhaps in the case of goalscoring an inferior rate of shooting accuracy is actually the driving force behind an increase in the ultimate aim of increased goal conversion rate.Is the coach's maxim of "Don't be afraid to miss" being embraced by the very best?

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