Sounders Insider

Zakuani MLS' second-most-productive player?

And in the first list released (based on April performance), Zakuani -- now out with a potentially season-ending leg injury -- shows up second behind New York's Thierry Henry.

Here's how the league defines the Castrol Index:

The Castrol Index tracks every move on the field and assesses whether it has a positive or negative impact on a team’s ability to score or concede a goal. A key factor for all areas of performance in the Castrol Index is in which zone on the pitch the action takes place. Players receive points for each successful pass they complete, but the number of points awarded depends on which zones the ball is passed from and received in. Similarly, misplaced or intercepted passes are penalised depending on how much trouble the mistake is likely to land the team in. The Castrol Index is also able to split up the rewards of a goal between penalising the goalkeeper for letting in a shot he should have saved and rewarding the attacker for scoring a goal. The number of Castrol Index points awarded for tackles, interceptions and blocked shots also depends on which zone they are made. Successfully taking the ball from a striker near the penalty spot will earn more points than a tackle out on the wing. Conceding free kicks and penalties will result in deductions.

Here's the league list. And here's the list of Sounders, which shows Zakuani, O'Brian White (also potentially lost for the season), Jhon Kennedy Hurtado, Brad Evans and Osvaldo Alonso as Seattle's five top-rated players.

Kasey Keller, by the way, ranks 166th in the league and 13th on the team -- numbers that may reflect more on the rating formula than on Keller.