Anyone who's read this blog before will know that the Kings are without equal at even strength puck possession, and that is a huge reason why they are one win away from the Stanley Cup. Throughout the regular season, LA's power play and penalty kill units were mediocre at best. Fortunately for the Kings, even strength is the most common (and therefore the most important) game state. Even so, they were going to have a hell of a time getting past San Jose and Chicago if their special teams units got outclassed. The acquisition of Marian Gaborik allayed those fears and helped transform LA's power play into a strength.
Our stat of choice to measure LA's power play performance is the rate of Fenwicks (unblocked shot attempts) generated per 60 minutes (FF/60). This is the most predictive power play stat, much more predictive than the more famous PP%. Using shots instead of goals and including unblocked shots increases the amount of data and lessens the effect of random variation, which is essential since teams spend only a handful of minutes a game on the power play. Here's LA's 2013-14 results:
As you can see, the power play was trudging along, mostly generating Fenwicks at a rate just barely above league average pre-Gaborik. LA put him on the top power play unit immediately after trading for him, and the shot rates jumped up. The difference is sizable. LA put up 72.1 FF/60 pre-trade, and 82.5 post-trade, rates that would be good for 16th and 3rd in the league, respectively, had the Kings done so over the full season. LA's power play slowed a bit in the postseason and put up 76 FF/60, which is still above league average (71.4). That number is actually even more impressive than it looks, because LA's postseason opponents have generally been good at shorthanded shot prevention (particularly the Sharks). The numbers were inevitably going to dip as the opposition got tougher, and it's a testament to LA's improvement that they remained above average at shot generation.
The question is, how much of this improvement is attributable to Gaborik? Well, it's hard to say. The team's power play shot generation has been better with Gaborik on the ice than any other King, but that might just reflect Gaborik joining at the same time as the power play was improving on its own. Gaborik himself isn't attempting a lot of shots; in fact, he attempts them at lowest rate of any King with regular PP time. (It might not be a surprise that Alec "he'll shoot" Martinez attempts power play shots at a higher rate than any other King.) Still, it seems plausible that Gaborik is helping the power play in other ways besides taking shots himself. His speed makes entries much easier, his goalscoring threat frees up room for other players, and he's a very good passer. Given that, and that he's getting a ton of power play time (second among Fs in the playoffs), I'm comfortable attributing a lot of the improvement to him, although I can't say exactly how much.
Of course, FF/60 does not tell the entire story of the power play. The rate at which those Fenwicks go in the net is critically important, especially over small sample sizes. As with even strength shooting percentage, deviations from league average in power play shooting percentage are mostly, but not entirely, due to luck. Only the sample sizes in the latter case are much smaller, which leads to even crazier deviations. The Kings 5v4 shooting percentage started off terribly (9.4% in the regular season, good for 27th) but has been fantastic lately (17.9% in the playoffs, which would have been 1st in the regular season by quite a bit).
As with the Kings' overall shooting percentage, their true talent lies somewhere in the middle. I don't think they're a way below average team, so that awful 9.4% was always a good bet to regress upwards. Marian Gaborik's arrival may have helped here, too. Of course, they're also probably not by far the league's best 5v4 sh% team; the rate at which the 5v4 shots go in is likely to go down moving forward.
The good news is that there are signs of improvement in the power play's underlying numbers, not just in the shooting percentages. The Kings have a legitimately dangerous power play now, one that's very good at getting the puck to the net. Trying to defeat elite team after elite team with an often-struggling goalie in these playoffs, the Kings have leaned heavily on that power play. With Marian Gaborik's help, it's delivered.