Thursday, April 15, 2010

Filet Mignon or Strip Steak?

The Capitals begin their opening playoff series tonight after an historic regular season that saw them produce the 7th most impressive offensive season in the history of the post-expansion NHL. A great deal of that production has come from the team’s top line, with Ovechkin and Backstrom permanent fixtures on left wing and center, respectively, and with the right wing slot being occupied by either Mike Knuble or Alexander Semin. Semin started the season on the top line before ultimately being replaced with Knuble, with the exception of sporadic games here and there where Boudreau would reunite Semin with Backstrom and Ovechkin for a period or two with the Caps trailing. To begin the playoffs, as it has been for the last few months fairly consistently now, Knuble will be on the top line.

Which version of the top line is more effective? These numbers suggest an answer. Note that Fenwick numbers are shots plus missed shots, and Corsi numbers are Fenwick numbers plus blocked shots.

The results are fantastic for both lines, but the numbers are particularly great for the Semin version. Their Goals For / Goals Against, Shots %, and On Ice EV Shooting % indicate an exceptional level of dominance for that trio. The Knuble line has a higher On Ice EV Save %, though it’s unclear that swapping out one player would drive the results to that extent. My best guess is that Semin played a higher percentage of his minutes with that line while the Caps trailed, which would skew his On Ice EV Save % (because the Caps would face fewer but higher quality shots while trailing). It appears that Semin and Knuble each had approximately the same number of total events (shots + misses + blocked shots for and against) when on the top line and trailing. Because Semin had fewer total events than Knuble on the top line regardless of game score, I think it means that Semin probably played a greater percentage of top line minutes while the Caps trailed, relative to Knuble. That certainly comports with my understanding of how Boudreau used that line. And because their shots against totals are lower, a few extra goals against while trailing (caused by Ovechkin, Backstrom, and Semin being in hardcore offensive mode) would disproportionately affect the On Ice Save % more so than the Shooting % or the Shots, Fenwick, and Corsi ratios.

That would certainly distort the territorial numbers (Shots, Fenwick, and Corsi ratios) in favor of Semin as well. However, those numbers so clearly skew towards Semin, and the percentage of time the Caps spent trailing is small enough, that I think we can make the general conclusion that territorially, and in terms of scoring efficacy, the top line was at its best with Semin on it. I think it’s an important point to make and realize, though it obviously does not necessarily imply that that is the line that Boudreau should use going forward, as it does not take into account any effects on other lines. And I’m fairly confident that Boudreau ultimately knows that Semin helps that line more than Knuble, as evidenced by his reuniting it down the stretch to help Ovechkin’s cause in the scoring and goal races. But depending on the way things go at various stages of the playoffs, Boudreau should not hesitate to reunite the line when he really needs a goal or to shift the momentum in his favor. I know he'll do it in the third if the Caps are down a goal, but I think there could be other times where going to the power trio earlier makes sense.

Incidentally, I looked at a couple other lines around the league that I thought might have approximated the Caps top line with Semin. It turns out, they did not. Ovechkin / Backstrom / Semin is a ridiculously good line.

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