Soccer is not a statistically driven sport. There are no batting averages, shooting percentages or yards-per-carry stats to consistently evaluate a player's performance.

Judging a player's contributions from game to game in soccer is almost completely subjective. Clint Mathis is a perfect example of that. Some Real Salt Lake fans love what he brings to the field, whereas others simply don't.

In soccer, it's all about wins and losses, and despite a plus-two goal differential, RSL sits in the bottom half of MLS with a 4-6-3 record. It's tough to single out and blame specific players for the sub-.500 record, but crunching some numbers and applying the plus-minus rating used in hockey offers some clues.

Hockey's plus-minus rating is a player's goal differential based on his individual time on the ice. Over the course of a season, and with countless line changes, this stat can vary widely between players on the same team.

This statistic doesn't fluctuate as much in soccer with a maximum of three substitutions per game, but with Real Salt Lake nearing the midway point of its season, there's enough sampling for the plus-minus rating to be relevant — and it reveals some surprising trends.

Of the 15 players who've appeared in six or more games for RSL, only Javier Morales at minus-2 and Robbie Russell at minus-1 have a negative goal differential based on their overall time on the field.

Most of the players fall in the plus-2 to plus-3 range, which seems logical with RSL's plus-2 overall goal differential. The only two players who fall above that range are Nick Rimando with a plus-6 and Jamison Olave with a plus-5.

As telling as these numbers are, they're also quite deceiving. In a 6-0 win over New England, RSL scored three of its six goals in the final nine minutes after the Revolution had all but quit.

By eliminating this statistical anomaly — which is fair, considering it's one of the most lopsided results in league history — some telling trends emerge. RSL's goal differential, excluding the New England triumph, is minus-4, with seven players sporting similar minus-3 or minus-4 ratings.

Interestingly enough, Tony Beltran — who didn't even play in the New England match — leads RSL with a plus-3 rating in eight matches. This after starting the year at minus-2 following his struggles in the season-opener at Seattle.

No other teammate has a positive rating, with only Fabian Espindola, Nick Rimando and Andy Williams checking in at zero.

Russell checks in with the worst rating when excluding the New England match at minus-7, and RSL's record when Russell starts is 0-5-3.

Russell isn't the only player to blame for RSL's losing record, but nonetheless he's a player who consistently seems to be on the field when bad things happen. Therefore, is he necessarily a must-start despite returning from a red card suspension this week?

E-mail: jedward@desnews.com