2015-16 Zone Entry Tracking

Last season, your pals here at FlamesNation changed up our original data collection for Calgary Flames regular season games.

We’re going to make some tweaks again – in part due to logistics and in part due to availability of comparable data – so we thought we’d take advantage of the lull before the beginning of the season to share them with you.

For the 2014-15 season, we added the tracking of offensive zone entries to our data collection. Fundamentally-speaking, this meant watching every game and tracking scoring chances (Corsi events within the “home plate” area in front of each team’s net), in addition to paying close attention to Flames players entering the offensive zone – which player entered, how they entered, and the time they entered the zone.

The upside was we were able to match up zone entry types with scoring chances, which resulted in the (predictable) conclusion that carry-in entries more frequently led to scoring chances. It’s what we thought the data would say, but we’re glad that it did. (We’d have been worried if it didn’t turn out that way.)

But the combination of (a) the time it took to track each game and (b) the fact that it was our first season tracking zone entries led to us keeping the categorizations really simple. Entries were either a carry-in, a dump-in, or an other. It was simple, but arguably a bit overly-so, and it lacked a bit of nuance.

So we’re shaking things up.

Good news and bad news regarding scoring chances: we’ll still have them, but we won’t track them manually. The web application that we used to track them manually has been discontinued, but the fine folks at War On Ice have been tracking them using their system. We compared the data last season and it was basically the exact same thing, meaning that us not tracking them saves us time and stress (and the quality of data is about the same).

Since we’ve saved some time on scoring chance tracking, we’ll be expanding the zone entry tracking in a couple ways.

First, based on our experiences watching games over the past few seasons – and seeking to replace vague anecdotal evidence with actual evidence – we’re tracking how many times the Flames (and their opponents) get “hemmed into their zone.” By that, we mean this: we’ll track every instance of the Flames keeping the puck in the offensive zone for 30+ seconds and every instance of them getting trapped in their own zone for 30+ seconds. And we’ll track which players are on the ice for each. Since getting trapped in your own zone can result in goals, scoring chances, taking penalties, or just plain getting worn down physically, we think tracking them will be useful for a whole number of potential projects.

Second, we’ve expanded the zone entry types:

We think that tracking these categories over a full 82-game season will provide some insight into what each player does with the puck, as well as provide some interesting findings in the aggregate.

We’d love your feedback during the season regarding what we’re looking at, and we’ll be sharing our findings periodically throughout the year. My hope is to do a monthly round-up (with both that month’s results and season-to-date findings).