I have occasionally written about defensive production in terms of how many goals, shots, or shots on goal teams allow in a match. One of the best of these measures, so far as I can tell, is whether a team allows their opponents to place accurate shots on goal. If you think about it, allowing an opponent to shoot is one thing - anyone can sling the ball in the general direction of the other side - but only accurate shots have a chance of actually crossing the goal line. In this sense, it's a much finer measure of what a team allows its opponent to do - or turn it around: it's a finer measure of what an offensive team is able to do to the other side.
So how have Premier League teams been doing on this score so far this year? First, the average accuracy score for opponents is .53 (or roughly 1 in 2 shots), with a range from a low of .48 to a high of .59.
There are some expected and some surprising patterns - take a look.
What is expected is that some of the top teams like Man U and Man City lead the league in preventing their opponents from getting off accurate shots when they make it in front of their goal. At the same time, what is unexpected is that Arsenal is among the teams least able to prevent their opponents from taking accurate shots. But what is expected is that West Ham, Wolves, and Blackburn are in their vicinity among the teams that allow opponents to take accurate shots. Unexpected is Liverpool's, Fulham's, and Wigan's relative defensive prowess - who would have thought the Latics do well in degrading their opponents' shooting precision?
As with offensive production, a factor that may underlie these patterns is differences across home and away play. So let's take a look at that; below are opponents' accuracy measures when teams play away (top panel) or home (bottom panel).
The first thing to notice is that teams defend better at home than away, as evidenced by the range of accuracy ratios in the bottom panel (home defense) extending to the left of the top panel (away defense). This is consistent with a home-team effect documented with regard to great a variety of performance measures.
Perhaps surprisingly, given their historically awful season so far, Liverpool leads the EPL in preventing opponents from making accurate shots when playing at home (allowing 4 of 10 shots to find the target), followed with some distance by Man U. And Roberto Mancini's Man City are the kings of "accuracy prevention" when playing away from home (an opponent accuracy ratio of .45), and with some room to spare relative to the second best team (Everton).
On the other side of the ledger, Blackburn and Chelsea have been least able to prevent opponents from making accurate shots when playing on the road, allowing over 6 of 10 shots to be placed well. So Blackburn's ability to allow only 6 of 31 shots on goal on Saturday at Stamford Bridge for a rate of .19 is a huge improvement over the club's performance this season. With 34% of possession, the final result could have been much worse than the 2-0 it turned out to be.
When playing at home, Stoke, Arsenal, and Blackpool have allowed their opponents to give their goalkeepers plenty of work to do. Arsenal is a bit of a surprise here, suggesting that Wenger is on to something when he is looking to reinforce his central defense in the transfer window. But of course, what we need to keep in mind is that a high ratio of accurate shots for opponents is one thing if we are talking about an average of 9.6 total shots Arsenal opponents take when playing at the Emirates, or an average of 12 for Stoke or 17.6 for Blackpool.
Can't wait to see how the second half of the season develops - and on both ends of the pitch.
