Is Dumping the Puck Damaging on the Power Play?

If thus far we've had the vegetables of power play analysis, now we scoop some potatoes.

Zone entry analysis was one of the biggest frontiers in hockey analysis over the past five years, but of course, it almost exclusively focused on even-strength play. I say, almost, because there is this piece from Eric Tulsky analyzing Philadelphia Flyers' (and opponents') zone entry power play data. Tulsky's finding -- one which was intuitive and yet somehow still surprising -- was that dump-ins aren't nearly as damaging relative to controlled entires up a man than they are at either strength. For a full understanding of that idea, go ahead and read that piece. Make sure you come back though, because his results were based on very limited data and were published five years ago.

Tulsky's findings were a little bit surprising because of how important we know that entering the zone with control is at even strength. At 5-on-4, when there is more space to enter the zone and less opponents to beat, you would think keeping the puck and not engaging in board battles from dump-ins would be more critical. But the findings were also intuitive because if you think about it harder, when dumping the puck in on the power play -- if the dump is well executed -- you can initiate 2-vs-1 battles rather than 1-vs-1 battles. As a result, the puck will be recovered more often on those plays leading to less immediate clears and more chances.

A couple of years after that initial look at zone entry data, Corey Sznajder tracked zone entry data for every team in the league, and luckily for us he included 5-on-4 data.

Now that it's 2016, and I have data from six teams, how do my results match up with those that Sznajder uncovered two years ago, both at 5-on-5 and 5-on-4?

Tulsky's findings are corroborated here. Unblocked shot attempts per controlled entry attempt stay relatively consistent between even-strength and special teams. The unblocked shots per dump-in rate, though, increases by more than a third. 

The reason why the percentages of total entries don't line up is because for my tracking I differentiated between a dump-in and an attempted controlled entry in which the player isn't able to keep control and the outcome is essentially an unintentional dump-in. I felt it was important to separate intention here, especially as we examine power play tactics and what players should be going for. Therefore, if you put the missed control percentage of total attempts row in with the dump percentage row, for my data you get approximately 22 percent uncontrolled entries, which bridges the gap between that and the 36 percent from 2013-2014 a little bit.

Still, that gap is notable, as is the difference in controlled entry success percentage -- 86 percent to 78 percent. We can't know this right now, but I wonder whether this is explained by a) The six teams I track being more carry-heavy than league average, or b) The league having trended more towards carry-ins, as speed as taken over as a factor, and even as analytic findings have painted controlled entries as being the vastly preferred option especially at even-strength.

Just based on eye-balling, I don't see these six teams as being significantly more carry-heavy than others I've watched. It doesn't take much in terms of penalty killing pressure to make the New York Islanders or Montreal Canadiens dump the puck in on the power play, for example. And since I know it will be asked, the Washington Capitals' results were well in line with the rest of the teams in terms of success rate and controlled entry ratio. A lot of the Caps' entry success stems from maintaining possession once the puck has strictly crossed the blue line, and setting up in formation quickly without losing that possession. Those ideas aren't assessed with this data, they were somewhat last week and will be more specifically later on.

So what's the takeaway? Well this is only the first step in the analysis of zone entries, and I believe there are better measures of zone entry success than simply whether the team has entered the zone in possession of the puck. That said, it's clear that controlled entries are still the preference. With a 5-on-4 or especially 5-on-3 advantage, teams should be able to craft meticulously rehearsed entries to free up an open man. That said, every team has slumps when it comes to entries -- the Caps were certainly an example of that the past few weeks -- so I wouldn't have a problem with a team dumping the puck in when it becomes clear that the timing on controlled entries and subsequent momentum is just not there. Even in situations like that, though, I would want my team to have specific set dump plays that were rehearsed and tricked the penalty killers into following the puck onto the wrong side, thus creating 2-on-1 or 3-on-1 battles to recover the puck. In other words, structured dump ins as a last resort? Yes. Improvised dump-ins just because they're easy and a coach won't bench you for a dump-in that is immediately cleared? No.