Tracking zone entries

Recently, Travis has written a lot about how part of the Flyers struggles have been the result of fancy play at the blue line instead of getting pucks deep in the zone.

It got us thinking about whether this was something that could be tracked. Geoff volunteered to do the hard work of actually keeping notes on game 3 of the Flyers-Sabres series -- lots of credit goes to him, and please use the comments to guilt him into continuing to do this. For every offensive zone entry (excluding dump-and-change plays), he noted which player sent the puck in and how they did it. After the jump, we'll take a look at what we can learn from this data.

Question 1: Who brings the puck into the zone for the Flyers at even strength? How do they do it?

Some things jump out at me from this table:

• Hartnell-Briere-Leino had a lot of offensive zone entries, ranking 2, 3, and 4 on the team. I'm not prepared to say that means they pushed the play forward though -- I suspect at least part of it was because they weren't deployed in tough defensive situations. When we have more than one game's data, we'll get a better handle on what to expect from a scoring line.
• Leino never wanted to play dump and chase (6 carries, one pass), which is why Travis was OK with his benching. Hartnell and Briere both dumped it in as often as any forward, however.
• I'm really surprised Zherdev didn't have a more active role in gaining the blue line. Carcillo was the only forward with as few zone entries as Zherdev.
• Timonen led the defense with 5 zone entries, while Syvret and Meszaros combined for 1. I would not have guessed that.

Question 2: What kind of play is most successful? Are the Flyers getting too fancy?

As a team, the Flyers controlled the puck across the line (carry or pass) half the time and dumped or tipped it in half the time. Again, with one game's data, I don't know whether that's high or low, or whether they do better or worse when carrying it in more. But I can look at which kinds of zone entries were most successful in this game:

The last two columns might need some explanation. "Shot attempts per entry" is how many Corsi events (on goal, missed, or blocked shots) the Flyers got before either the puck came out of the zone or there was a whistle. "Counterattack frequency" is how often the Flyers' zone entry was turned back quickly and forcefully enough for Buffalo to get a shot attempt within 30 seconds.

There are a couple of other things that I didn't show because of small sample sizes. I am also tracking which entries result in offensive zone faceoffs, so we know how every zone entry ends -- with a goal, a zone exit, or an offensive zone faceoff. We can also treat the faceoff as another kind of zone entry and track how well teams do at getting shots and goals off of the faceoff, before the puck leaves the zone.

Back to the question: what kind of play is most successful? It shouldn't be a surprise that if you can control the puck as you enter the zone, you are often better set up to get the offense going and generate shots. But while I'm not going to draw general conclusions on one game's data, the difference here is larger than I expected. The Flyers got 0.74 shots when they carried or passed the puck in, versus 0.21 when they dumped or tipped it in, with only a marginal difference in counterattack frequency. Carrying the puck in was quite effective in that game.

Question 3: Whose zone entries are most successful? Who do we want to have the puck?

Carter brought the puck into the zone 8 times in game 3, and those 8 possessions generated eight shot attempts. In contrast, HBL's 20 combined zone entries generated only 6 shots (including just 1 in Hartnell's 7 entries). I won't generalize from just one game, but Carter did generate a lot of offense on Monday.

On the flip side, 4 out of the 6 times Richards brought the puck into the offensive zone resulted in a quick shot for Buffalo. Again, don't read anything predictive into the small sample size, but in that one game the Flyers were better off taking a faceoff in the neutral zone than having Richards control the puck approaching the blue line.

Question 4: What can we learn about the power play?

Again, the sample size is tough. Watching one of the worst power play teams in the league for a single game doesn't provide enough information to generalize on effective strategy. But I will say that it doesn't seem like a good thing that with an extra man on the ice they were able to carry out a controlled entry only 33% of the time: they had three carries, four dumps, a tip, and an "other". That's probably a big part of why they generated only four total shot attempts and only two shots on goal on the power play.

Question 5: Does strategy change as a function of score?

It is a virtual certainty that we don't have enough data yet to answer this question. But let's take a look anyway, just for fun.

Since score effects get larger with either a larger score differential or a bigger lead, I'll draw the line at 16:44 in the second period, when Zherdev made it a two-goal game for the first time. Before that arbitrary dividing line, the Flyers had 22 entries by pass or carry and 22 by dump/tip/other. After that line, they had 12 entries by pass or carry and 11 by dump/tip/other.

The entries per minute got slightly smaller (from 1.2 to 1.0), but the style of entry didn't -- they didn't appear to be just dumping it in deep and forechecking. Even in the last three minutes of the game, they twice carried the puck into the Buffalo zone.

Conclusion

Geoff is always encouraging me to put a tidy conclusion at the end of my stories; I'll humor him on this one, since he did a lot of the work for it. I'm excited to see what we can learn by tracking zone entries going forwards, both about team strategy and about individual performance. Even just a single game's data highlighted an individual who carried the puck in a ton (Leino), an individual who didn't carry it in nearly as much as I'd expect (Zherdev), and a surprisingly large differential in team success on carries versus dump-ins.