Lineup turnover impacts results. We've previously shown that game-to-game lineup consistency leads to improved results for Seattle. Similarly, having a core lineup available and active on the field tends to improve the quality of play from Seattle or any other team. The graph above exhibits diminishing results for the current top 8 teams in the Supporters Shield standings with increasing use of the deep roster. "Missing" minutes are calculated by measuring, in a given game, how many minutes are given to players other than the core roster (defined on the x axis by players ranked in descending order of minutes played - excluding goalkeepers for the sake of simplicity; the theoretical maximum for bins 10-13 above is all 900 minutes). For example, the top 5 outfield players for Seattle in terms of minutes played so far in 2015 are Tyrone Mears, Brad Evans, Chad Marshall, Marco Pappa, and Clint Dempsey. The absence of Evans and Dempsey from Saturday's game gives Seattle 180 missing minutes for the top 5 outfield players. 370 minutes were given to players outside the top 10 - the second highest value on the season, trailing a mark of 540 in the FC Dallas road draw in March. This metric is negatively correlated (if somewhat weakly) with team performance when measured by points or by goal differential:
Among the top 8 teams so far in 2015, the strongest impact on performance has been absences among the 3 most regular players on the roster. Seattle has actually seen fair results in such games, tallying 2 wins and a draw in the 4 games Zach Scott has replaced either Brad Evans or Chad Marshall.
The evidence that poor officiating cost Seattle a result in Kansas City hurts, but the team must be encouraged by the continuing strength of the deep roster. In the 20 games current MLS contenders have "missed" 300 or more minutes from the top 10 outfield players, they have averaged 1.15 ppg. In the 8 games teams have met or exceeded Saturday's mark of 370, contenders have 2 wins (ironically, both belong to Kansas City) and 2 draws. Going on the road with such a depleted roster against such competition, the Sounders should be encouraged that the deep roster deserved a result against KC and previously against Dallas.
These numbers also show Seattle's roster usage has been somewhat different than its immediate competition thus far in 2015, measured against average missing minutes per game:
The 2015 Sounders have relied heavily on the rotational roster, balancing relatively lesser playing time for ranks 5-7 with above-average use 11-13. That the team nevertheless retains a ppg lead in the standings bodes well for its durability over the course of the full season.