How defencemen defended their blue line against zone entries in the 2022 Stanley Cup Playoffs

I decided to manually track all 89 games from the 2022 edition of the Stanley Cup Playoffs again, after how much fun we had with last year's project. I don't necessarily want to rehash everything here, but let's do a quick refresher of why we're doing this before we dive into the data. 

We're specifically focusing on what defencemen do in transition at both bluelines, with and without the puck. In this upcoming first part, we're going to look at how actively they were able to defend against opponents trying to enter the zone against them. In the second part of the series, we'll switch over to evaluating how they did when trying to transition the puck out of the zone while breaking out. 

Both are quite important skills, but obviously wildly different ones so we'll take them separately one at a time. 

I truly believe that rush defence it's an essential skill in today's game, which is why I value it so highly. There are a couple of exceptions to the rule that allows a team to get away with allowing a higher proportion of clean entries. Sometimes the personnel is so good at in-zone defending that they efficiently clean up whatever happens next. But for most defencemen, they simply can't afford to play that kind of game if they wish to avoid getting caved in regularly. 

A high percentage of even-strength scoring these days is done on the move, and the best offensive teams are generally the ones that can quickly strike before the defensive structure is able to get set. Scoring chances immediately following entries are especially dangerous, and you need to be able to proactively prevent that from happening before it's too late.

The defensive blue line should be treated as a high leverage entry point, where big plays are either stopped in their tracks or allowed to be created. This is precisely why we should care about how defencemen choose to play those sequences, and whether they passively sag back or whether they aggressively jump up and try to provide resistance. 

By tracking the events in which each defender is the primary target of the opposition's attempts to enter the zone, we can get a better sense of their tendencies, their ability to handle speed, and hopefully more accurately isolate their individual contributions to the overall defensive on-ice results. That's the plan heading in at least, so here we go.