After Howard Webb's second questionable red card shown to a Fulham player this season, we will find ourselves hosting Manchester United this Saturday without one of our key January signings. Leon Andreasen has made quite an impact since joining just over a month ago - since he has been inserted into the starting lineup, we've conceded less than a goal a game.

Even in a statistics-friendly sport like baseball, defensive metrics are tricky. That doesn't stop us from trying, though. Traditionally, baseball defence has been measured in errors and fielding percentage - the number of times a player makes a defensive mistake, and the percentage of mistake-free touches. The obvious flaws here are subjectivitiy (as in, what constitutes an error), and the fact that if a player is too slow to get to a ball in play, he cannot be considered to have made a mistake. In the 1970s, Bill James created a statistic called range factor. This addresses the second problem by adding up the number of assists (awarded to every defensive player who touches the ball prior to an out) and putouts (awarded to the player who actually records an out) per game. In theory, better and more athletic players will carry a higher range factor as a result of making more plays defensively.

Applying this to football, I've added up the number of fouls, tackles, clearances, and 50-50 contests won. Here are our midfield players, plus part-timers Volz and Stalteri:

The sample is small, but you can see that Andreasen has already filled a huge void. Thankfully, Hodgson had the foresight to add some depth. Paul Stalteri played a defensive midfield during his days at Werder Bremen (perhaps Andreasen was his immediate replacement...?), Toni Kallio has experience in that role, and Volz has filled in for us in the past. Whoever plays, he'll have some shoes to fill.