The MLS MVP award won't be announced until MLS Cup week, but it's a fair guess that the finalists will include Mike Magee, Marco Di Vaio, and Robbie Keane. The award is ultimately subjective, but objective indexes like the Castrol Index can help differentiate between three worthy candidates.
The case for Magee is the most subjective, based largely on how his breakout season turned around a Chicago Fire squad that was wallowing at the bottom. The argument against his candidacy is that the Fire ultimately didn't make the playoffs, which is again subjective criteria.
The argument against Robbie Keane is the amount of time he missed this season (1,982 minutes played this year almost 800 fewer than both Di Vaio and Magee). There's not much arguing against how effective he was in that time, averaging more goals per ninety (0.73 per 90) than Magee or Di Vaio.
Of the three, Di Vaio has gotten the least public campaigning, and much of that has to do with the sharp decline of Montreal's play toward the end of the year. The club only made the playoffs because Chicago fell just short on the final day, and Di Vaio finished behind Sanvezzo and Magee in the Golden Boot race.
What the Montreal striker has working in his favor is how many goals came from open play; which is all of them. A third of Keane's goals came from the penalty spot, which count for less in the Castrol Index. Keane took over PK duties as well as the armband from Landon Donovan this season, and without those penalties he'd finish below Jack McInerny in the goal list.
Those five goals from the spot also hurt Keane's average distance on his goals. The image above shows the location of all 16 of his goals this year, and it's clear that outside of those five at the spot there are five others taken from an even further distance. More than half his goals coming from the penalty spot or further gives him an average goal distance of 19 meters (16m for Di Vaio, 17m for Magee) which also hurts him in the Castrol Index. Further distance means more blame can be assigned to the keeper.
This is all in the service of differentiating Keane's goals from the other main candidates, but we haven't yet considered his assists. From open play, Keane had just as many assists as goals and he's the only player who finished in the top five in assists as well as goals. In all he's credited fifty-five chances this season, only four fewer than assist leader Diego Valeri.
The argument against Keane's assists is that none of the other candidates had a partner like Landon Donovan. Donovan's ten goals tie directly into Keane's eleven assists. Does Keane having Landon Donovan as a partner dampen his claim to most valuable?
This is just a sampling of the questions that have to be considered when selecting a player as the most valuable. Who do you consider the front runner for the 2013 MLS MVP?
Castrol Index statistics provided by Castrol statisticians.