How important are faceoffs to possession in women’s hockey?


This was co-written by Mike Murphy, Alyssa Longmuir, and Shayna Goldman based on work for the Big Data Cup and Ottawa Hockey Analytics Conference
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As a result of women’s hockey analytics needing to play “catch up,” it’s not unusual to see analysts relying on stats that have already been proven to be less insightful in the men’s game. One such area of the game that is frequently highlighted at the collegiate, professional, and international levels of the women’s game are faceoffs. 

Faceoffs have been covered extensively in men’s hockey, and much of that work points to the fact that faceoffs wins aren’t all that they’re chalked up to be. Back in 2015, Arik Parnass, now of the Colorado Avalanche, found, “This … aligns with what hockey analysis has found over the years when it comes to faceoffs. Overall, winning them just isn’t as important as it’s made out to be.” 

While a great deal of work has been done on the importance (or lack thereof) of faceoffs in the men’s game the same cannot be said of women’s hockey. But why would it be any different? 

Generally speaking, the rules against body-checking in the women’s game put an emphasis on puck possession and passing. That rule could also influence the role that wingers play in winning draws, and, more importantly, make “winning” the puck in a faceoff more valuable than it is in the men’s game.

To examine how valuable faceoffs are to possession in the women’s game, we looked at all net shots post-faceoff for all games in Lake Placid using data provided by Stathletes, starting at the NWHL (National Women’s Hockey League) level. The NWHL follows NCAA rules that assess at least a minor penalty for any kind of body checking. 

Our approach was inspired by Craig Tabita’s work for hockeyprospectus.com and Gabe Desjardins’ work on the topic, published in 2011 on SB Nation. Alison Lukan highlighted Tabita’s work in an article she wrote for The Athletic in 2017: “Tabita found that after 10 seconds of play, regardless of where a face-off occurs (neutral zone, offensive zone, defensive zone) that shot volume evens out to be more or less the same.”

Following Tabita and Desjardins’ work – and with other research on the value of faceoffs in mind – we looked at net shots post-faceoff for the 15 NWHL games in Lake Placid to determine if faceoffs are potentially more valuable in the women’s game than they are in the men’s game.

Overview

We expected to see a difference in net shots post-faceoff in the offensive zone – perhaps a longer window than Tabita’s 10 seconds –  but were unsure what we’d see from neutral zone and defensive zone draws.

We looked at every event from the NWHL data set and isolated the faceoff wins that ended with a shot. We then broke down data to compare shots by seconds after a draw, comparing the numbers for each zone. 

From a sample of over 200 faceoff wins – 166 offensive zone, 15 neutral zone, and 20 defensive zone – we, predictably, saw the most noticeable spike in net shots post-faceoff from the offensive zone. The majority of those shots came quickly off the draw – within the first four seconds. The longer time rolled on post-draw, the fewer shots generated that reached the net. That generally lines up with Tabita and Desjardins’ work. But the drop off in net shots in the seconds to follow do pose the question as to whether faceoff wins truly make a difference in sustained pressure; teams could be simply firing shots quickly and having to shift right back to defense. 

Unlike men’s hockey, there are spikes in net shots after draws in the neutral zone and defensive end. Most shots generated after neutral zone draws occur in the four to eight second span of time after the faceoff. Shots created after defensive zone draws often take more time – somewhere in the eight to 10 second range. 

Weaknesses

The biggest weakness of our research is sample size. The NWHL’s play in Lake Placid was intended to be a condensed two-week season featuring round-robin games and the playoffs because the pandemic impeded their ability to put on a regular season. What we ended up with was 15 total games. Comparatively, the 2019-20 season featured 24 regular season games per team. 

What’s also tricky about focusing on Lake Placid is that teams played an uneven number of games due to COVID-19 related factors. The Metropolitan Riveters played just three games, while the Boston Pride led the league with seven. Of course, not all teams are created equally in regards to their success in faceoffs or puck possession. Unfortunately, that was just the tip of the iceberg when it came to wrinkles specific to Lake Placid. It was an altogether unique setting.

Teams were unable to have a typical training camp and offseason preparation, the condensed schedule left little time for adjustments to be made by coaching staffs and applied by players, and teams had more players at their disposal for games than they did in years past. 

The NWHL’s bench usually consists of nine forwards and seven defenders, and possibly features players roving between positions within those constraints. For Lake Placid, the benches were extended to allow 12 forwards. That depth may have changed average shift lengths, which can affect possession as well.  

At the very least, exploring data from Lake Placid gave us a starting point for further research.

Further Research

Having a full season – or at least one standard season of NWHL hockey – could help provide more insights into the importance of faceoffs on shot generation, and eventually, scoring. 

Pairing this data with video would also provide further insights and could provide direction for application by players and coaches, as it would help show how those playing alongside the center can help drive play to maintain possession, whether there’s quick puck movement or more protection around the center to make the most of the possession gained from a faceoff win. 

The process of moving the puck up the ice after neutral zone and defensive draws could be studied with video as well, as it would help us determine just how key winning a faceoff was to the eventual shot. 

Conversely, we can try to learn more about how teams regain possession after losing draws and how they limit shots that result from their opponents winning draws – that should give us more insights into the overall impact of rules against body-checking and how they affect game flow and possession. 

So, from our research on the condensed 2020-21 NWHL season, there appears to be a connection to faceoff wins and generating shots. The timing of those shots varies based on where the faceoff was won; each appears to be in accordance with the distance needed to get from the dot in that respective zone to the net. 

While the findings in the offensive zone were similar to those done in men’s hockey, it appears that there is more value in winning faceoffs in the neutral and defensive zones in women’s hockey based on the spike in shots post-draw. The level of that value, though, is still undetermined due to our limited sample of games. 

Since presenting at the Ottawa Hockey Analytics Conference, we went back to look at league play-by-play data from 2017-19 to determine if there was historical precedence for our findings from the Lake Placid data. We found that over a longer stretch of games the curves became dramatic with shot attempts being able to be made at close to even rates across the three zones. While similar to men’s hockey, offensive zone faceoffs still provided the initial offensive impact in the immediate 5-10 seconds after the subsequent faceoff. However faceoffs in the defensive and neutral zone both yielded significant and in some cases greater shot density in the 10-20 seconds after the initial event.

Needless to say, this reinforced our findings from Lake Placid that faceoffs are more valuable in possession in the women’s game than they are in the men’s game. While there is still work to be done, it’s safe to say that there is ample evidence suggesting that winning faceoffs has real value in women’s hockey.

This is an intriguing example of why we can’t assume conclusions drawn from the analysis of data in men’s hockey can be applied to the women’s game. There is definitely something to be learned from studying these concepts in women’s hockey as well.

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