Darren Mattocks vs. Kenny Miller, by the Numbers

If there's a popular narrative in Vancouver Whitecaps circles it's that Martin Rennie is showing too much preference to his Scottish players, Kenny Miller and Barry Robson. In particular, Miller, who has been starting lately ahead of rookie phenom Darren Mattocks, has been getting into trouble for poor touches and a lack of production. It's almost enough to make you forget Mattocks hasn't scored since July.

So what is Martin Rennie to do? Has Darren Mattocks been playing good, scoring-chance generating soccer but just hasn't gotten enough playing time to pour in the goals? Is using Kenny Miller more just exposing his lack of goalscoring ability whereas Mattocks is generating more per minute? Or are they both in the dumps, just two parts of a team that's been hurting for offense since the summer?

Neither forward has been at all good. Mattocks's numbers are boasted by an excellent July 27 game against Real Salt Lake where he attempted five shots, got one on target, and it went in. If we're looking strictly at recent form rather than since-Miller form Mattocks has only two shots on target, total, from August to today in 364 minutes. But Miller's been stinking it up too. Mattocks is averaging 0.68 shots on target per 90 minutes since Miller's debut, and Miller is averaging 0.51.

By comparison, Eric Hassli averaged 0.70 shots on target per 90 until he was traded for ineffectiveness, offensive disappointment Sebastien Le Toux managed 0.66, and Camilo leads the team with 1.23. Chris Wondolowski, one of MLS's premier shooters, has 1.75 shots on target per 90 minutes this season, and Thierry Henry has 1.61. Even merely decent forwards, players like Edson Buddle (0.81), David Estrada (0.88), and Andrew Wenger (1.01), leave Mattocks and Miller in the shade.

Almost all of Major League Soccer's serious scorers average at least 1.00 shots on goal per game. Shooting percentage tends to be constant and will therefore regress to the mean over time^[1]; therefore the best scorers long-term are those who get the most shots on target. (Bet the farm against Patrice Bernier next season, who has scored nine times on fifteen shots.) So Mattocks and Miller's inability to get shots off is killing them both. Mattocks is generating shots somewhat more frequently since Miller arrived but it's close, neither number is good, and Mattocks's post-July figure of 0.49 shots on goal per 90 minutes is even worse than Miller's.

Mattocks has outplayed Miller since Miller arrived, but the difference is marginal and both have been inadequate, while Mattocks has tanked completely since the end of July. Which one Martin Rennie should play, therefore, should depend entirely on the old coaching canards of "picking the hot hand" and whichever one he thinks can best exploit the defense. Miller has been lousy, but that in no way means Rennie has necessarily been wrong to use him: Mattocks has been every inch as bad.

[1] — Grayson, James W. "Shooting percentage – part I." James' Blog, March 30, 2011. Accessed October 23, 2012. http://jameswgrayson.wordpress.com/2011/03/30/shooting-percentage-part-i/. Note to the curious: read the whole series.