Brad Evans is not a particularly creative midfielder.
...but put him on the backline with space to move and no mark to worry him, and he just may unleash a perfectly-weighted long pass that releases Obafemi Martins, who then proceeds to touch a shot around the keeper and, unfortunately, wide of the goal. Putting Evans at center back modestly increases a team's chances of generating a key pass from that position... it had just better not be the only key pass of the half if said team has any expectation of winning.
Evans' example there is a simple exception to an easy rule: generally, a player's role is a pretty good clue as to whether a particular on-field action is likely to be goal dangerous. Zach Scott's ~15% pass share against Los Angeles, for instance, was a poor sign for the Sounders offense, even setting aside the particular result of one errant ball. The distribution of actions within the team is a decent indictor of working tactics and good performance.
The positional pass share is defined here as the "average" midfielder or forward among starters (not including Chad Barrett's 4-minute stint) in a particular game - Seattle has tried 3, 4 and 5-midfielder setups as well as 1, 2, and (allegedly) 3 forwards, so summing up positional totals can be misleading. The Sounders have been considerably better when the forwards take a higher distributional share (though this is an oversimplification of the personnel issues - Martins and Clint Dempsey are relatively high-volume passers, Barrett and Neagle are not) and midfielders take an intermediate share. Although these numbers would ideally be adjusted for game state, substantial game-to-game shifts away from the optimal values reflect a struggle getting the ball to the right feet.
The SaH game thread for Sunday's draw against Houston wasn't particularly kind towards the Dempsey/Martins forward pairing, but the numbers reflect a midfield that failed to get them the ball at the needed rate, much as Sigi Schmid acknowledged in the postgame comments. Gonzalo Pineda sat deep in the game, with Erik Friberg absorbing much of the CM's typical offensive movement as well as that of his own position out wide. Andreas Ivanschitz, starved for service to provide width, contributed his characteristically low-pass volume mainly in the center until Houston's lead and Sigi's second-half adjustments pushed him wide. Seattle's continuing difficulty working new personnel into the midfield is a far more pressing problem than any perceived deficiency in finishing from the forwards. The team is running out of time both to make the playoffs and to construct a strong bid for the MLS Cup. If the new pieces don't fit, it may be time to rely on the old... or at least construct a 4-4-2 tactic familiar from the successes of the early season.
Raw data for this work was collected from OPTA via whoscored.com.