Capitals vs. Bruins – Tracking puck possessions

Updated: March 6, 2013 at 12:31 pm by Cam Charron

There’s been some talk about the importance of hitting in the hockey blogosphere lately. Most of it has come on Twitter in the wake of the Edmonton Oilers trading for Mike Brown and to whether or not Brown’s hitting will make a lick of difference to the Oilers lineup.

My gut reaction is “no, no it won’t”. I did a big of leg-work in this post at the Backhand Shelf that showed “hits” “giveaways” and “takeaways” were subjective statistics that didn’t really mean anything. Every scorer in every building has a different definition of a hit. What I wanted to see was whether actual hits lead to turnovers in any given game.

So I watched the Washington Capitals-Boston Bruins game Tuesday night and will probably watch a couple more games until I conclude anything, but I wanted to get some suggestions as to how I can improve my model. In basketball, the number of possessions is easy to deduce from the scoresheet: Shots Taken + Turnovers + Blocked Shots – Offensive Rebounds. There are more ways that a possession can “end” in a hockey game:

Dump In: A puck shot into the attacking zone directed at nobody in particular.

Dump Out: A puck shot out of the defending zone directed at nobody in particular.

Shot: After an offensive chance, the defence recovers the puck.

Pass: An intercepted pass.

Takeaway: A forced turnover where the defending player targets the offensive players’ stick or the puck to win control.

Hit: A forced turnover where the defending player targets the body to win control. Also counts when a hit forces the offensive player to make a bad pass.

Faceoff: If control from the previous sequence is changed off the ensuing face-off (this was to ensure that teams alternated possessions)

Period: The end of a period, or, in the case of Tuesday’s Washington-Boston game, the overtime goal.

So just to see how possession of the puck changed hands… the Bruins had 193 possessions and the Capitals had 194:

Possession ended by… Washington possessions Boston possessions
Dump In 40 40
Dump Out 25 27
Shot 21 27
Pass 40 44
Takeaway 29 26
Hit 22 16
Faceoff 16 13
Period 2 2

The RTSS counter gave Washington 23 hits and Boston 22. I had them at 16-22, so either the Capitals were credited with some ‘phantom’ hits or their definition was different than mine. The big difference was in giveaways and takeaways, of which they were plenty on both sides. I had giveaways at 44 for Washington and 40 for Boston, but the scorer had them 12-6.

Anybody with some suggestions on how to improve this? I’m not looking to find out which players are good at these sorts of things, I just think it’s important to quantify how the puck changes hands in the NHL.