A deep dive into penalty differential in the NWHL

Last year, Daniel Weber moved the ball forward in the world of women’s hockey analytics by tracking and releasing data on penalties drawn in the NWHL. At the beginning of the 2019-20 season, I asked Karl Hendela, the NWHL’s Statistics Coordinator, to track penalties drawn for players — among other things. The infinitely helpful and patient Karl agreed and provided me with the data at the end of the season.

For those who don’t know, penalty differential (PenDiff) is simply the difference between the number of penalties a player draws and the penalties (of all types) that they take.

A player “draws” a penalty whenever they are on the receiving end of an infraction by an opposing player that results in a penalty. So, no one would be credited with drawing a penalty when a team gets called for having too many skaters on the ice. The same is true of penalties like unsportsmanlike conduct.

Naturally, players should want their penalty differential to be in the green in the same way they might want to be in the green in their +/-. However, different players play different roles and some of those roles — i.e. a physical, stay-at-home defender — come hand-in-hand with taking penalties.

It’s also important to recognize that drawing penalties is a skill which often goes overlooked when we focus too much on boxcar stats like goals, assists, shots on goal, and +/-.

Furthermore, when we look at penalty differential at the team level, we can infer — when we take into consideration other details, including shot differential —something about puck possession. When do players tend to draw the most penalties? When they have the puck.

Trends and the Big Picture

The 2019-20 regular season was 24 games in length, the longest in NWHL history. When it comes to data analysis in sports, the longer the season the better — because more games means a larger sample size.

Now, let’s break down a few trends by position.

• Forwards: 65 players with a combined +45 penalty differential
• Defenders: 35 players with a -71 differential
• Swing Players (F/D): 7 players with a -15 differential
• Goalies: 14 players with a +8 differential/

I made the classifications for “swing players” (players who play both forward and defense) based on the league site and through my own observation. Because we are looking at a group of just over half a dozen players and because the classification of swing players is exceptionally subjective, we shouldn’t read too much into the PenDiff data here.

No goalies took any penalties this season and there were eight goalie interference calls, hence the +8 differential. Amanda Leveille led all goalies with two drawn penalties.

As far as forwards and defenders go, it scans that the league’s forwards finished in the green and that the league’s D finished deep in the red. That is all the more reason to acknowledge those defenders who broke even in PenDiff, or finished in the green or, in the case of Marie-Jo Pelletier, drew four penalties and took zero penalties of their own in 24 games.

Boston Pride

With the exception of the ever-aggressive Kaleigh Fratkin, the Pride were a remarkably disciplined team in the regular season. The Pride, who routinely dominated in the shot share, finished the year with the highest team penalty differential in the league (+15). Yep, it sure is nice to own the puck.

It should be noted that Fratkin’s aggression is very much an asset and a part of her game — as evidenced by her winning the 2020 NWHL Defender of the Year Award and being on the ice for three All-Star Games. There is a strong case to be made that Fratkin would be a less effective player if she played with less of an edge to her game. With that being said, she definitely stands out from her teammates with 19 minor penalties — eight more than any other Pride skater.

Boston’s most proficient skaters at drawing penalties were captain Jillian Dempsey (14), rookie center Lexie Laing (14), shutdown defender Lauren Kelly (15), and veteran forward Emily Fluke (11). And yes, this is just one more thing we can add to the long list of things that Dempsey is great at.

Laing’s numbers deserve a closer look. She led the league with a +12 PenDiff as Boston’s second line center.

Her gift for putting the most dangerous offense in the NWHL on the power play was just one more layer to one of the most underrated rookie seasons for a center in recent memory. Laing scored plenty of points in her debut NWHL season, but her discipline didn’t get nearly as much attention as it deserved. She was one of Boston’s best defensive forwards, maybe second only to Dempsey, and took just two minor penalties in 24 games.

Buffalo Beauts

The Beauts were by far the most physical team in the NWHL this year and, as a result, they finished the season with several players deep in the red in penalty differential. That fact should come as no surprise to anyone who watched Buffalo with any kind of regularity this year. No team seemed to get in their own way as much as the Beauts did this season with their constant march to the penalty box.

At the team level, Buffalo was shorthanded 120 times in the regular season, which is 10 more times than the second-most penalized team, the Metropolitan Riveters. One can’t help but wonder what kind of impact a little more discipline could have made to the Beauts’ record of 8-15-1. It also speaks volumes that two Beauts defenders — Meg Delay (-12) and Lenka Čurmová (-11) — finished with the second and third-worst PenDiffs in the league, respectively.

MJP’s penalty-less season was a pretty big outlier on the most-penalized team in the NWHL, but it was sniper Taylor Accursi and talented rookie winger Brooke Stacey who led the way with +5 PenDiffs. Rookie forwards Erin Gehen and Cassidy MacPherson also deserve recognition for finishing level with Pelletier with +4 PenDiffs of their own. And, although it’s a sample size of just six games, Kristin Lewicki’s +3 is definitely noteworthy. Lewicki is just one example of an emerging correlation between being an elite skater and excelling at drawing penalties.

Another standout from the Beauts was emerging agitator and power forward Iveta Klimášová. The Slovakian rookie took 20 penalties and finished the season second in the league with 43 PIM. Klimášová definitely went through an adjustment period in her first few months playing pro hockey in North America. She took penalties in 13 of her first 15 games, and finished the season with four minors in her last nine games.

Connecticut Whale

The Pride had the best team differential in the league, but, in my opinion, the Whale’s team discipline was probably the most-impressive.

Connecticut finished the year with a +2 PenDiff. That is a remarkable feat for a team that was out-shot by an average of 9.75 shots per-game and spent as much time as the Whale did playing in their own zone, especially at even strength.

Winger Sarah Hughson set an NWHL record by becoming the first forward to play in 23 games in a single season without taking a penalty. Her +4 PenDiff was tied for second on the team with versatile veteran Kaycie Anderson and trailed only Kendra Broad. Broad left the Whale before the end of the season to play in the Elite Women’s Hockey League (EWHL) with Aisulu Almaty.

Now, let’s talk about the captain. Shannon Doyle’s -1 PenDiff is a prime example of just how important context is when we look to analyze and better understand performance with data.

Doyle drew twice as many penalties (17) as every Whale skater except Broad (13) while also leading the team in penalty minutes (36), blocked shots (65), and sharing the team lead in scoring (11). Events tend to pile up in box scores when you are on the ice as much as Doyle was in the 2019-20 season. And she was on the ice a lot.

Each of those events represents a brush stroke that helps paint a picture of how integral Doyle is to Connecticut’s identity. It’s hard to imagine what kind of team the Whale would be without her.

Metropolitan Riveters

The Riveters were the only team in the league that gave the Beauts a run for their money in the penalty department. The Rivs finished the season with 299 PIM; the Beauts’ had 317.

Let’s start with the captain. Madison Packer finished the season with a  +1 PenDiff, but, much like Doyle’s -1 PenDiff, there’s a lot behind that narrow margin.

Packer led the league with 48 PIM but, more importantly, also led the league with 18 drawn penalties. It’s also important to note that her penalty total was inflated by two 10-minute game misconducts — one against the Pride on Dec. 7, 2019 and another against the Beauts on Feb. 15, 2020. The second-highest scoring player in NWHL history definitely has a gift for getting under the skin of her opponents and getting refs to raise their arms.

Another player who deserves a spotlight for drawing penalties on the Rivs is Kate Leary.

The 2020 NWHL Newcomer of the Year was a dynamic, effective puck carrier who gave her team a lot of power play opportunities. Leary finished the season with a +8 PenDiff, good for third in the league. She was also second in the league with 17 penalties drawn — more evidence that she was one of the most dangerous players in the NWHL this year.

Rebecca Morse, who recently re-signed with the Rivs for a fifth season, had a -9 PenDiff. That was the worst margin on the team and the fourth-worst in the league. Morse went from taking five minor penalties in the first 31 games of her NWHL career to taking 17 minors in 24 games in 2019-20. How and why did that happen?

Morse was a fixture on the Rivs’ top pair and that meant she was on the ice a lot, especially at even strength. It also meant that she tried to clean up a lot of the defensive breakdowns in the neutral and defensive zones that plagued the Riveters in the first few months of the season. It comes as little surprise that eight of Morse’s 17 minors were picked up in the seven games she played against Boston. Sometimes, taking a penalty is a better choice than allowing an opposing player to have an unmolested prime scoring chance.

With that being said, the Providence alumna will want to spend a lot less time in the penalty box next season.

Minnesota Whitecaps

The Whitecaps, like the Pride, dominated in puck possession throughout the season, as evidenced by a +6.92 shot differential per-game and a +41 even-strength goal-differential. However, Minnesota took far fewer penalties than the Pride.

Minnesota had five players finish with at least a +6 PenDiff — Boston had two. Defender Chelsey Brodt Rosenthal led the Whitecaps with eight penalties, but was tied for 25th in the league in that category. If you’re looking for the NWHL’s cleanest team, look no further.

Anyone who has watched Minnesota with any kind of regularity over the past two seasons can attest to the excellence of Amanda Boulier as a puck-carrier. On a team with speedsters like Allie Thunstrom, Jonna Curtis, and Meghan Lorence, it was Boulier who led the way by drawing 12 penalties. She also led all NWHL blueliners with a +7 PenDiff — oh and she had 27 points in 22 games. No bigs.

There are few players in the world who can dart up the ice like Boulier. Her quickness often forces opposing players to take stick infractions in attempt to slow her down and prevent her from making the big plays that led her to piling up 17 primary points in 22 games.

Perhaps the biggest surprise from Minnesota’s penalty data in 2019-20 is that Thunstrom drew “only” nine penalties. At the onset of the season, I would have called her a safe bet to lead the league in total penalties drawn because of her breakaway speed. Then again, you have to be able to catch someone in order to take a penalty on them.

Also, even if you can catch Thunstrom, her hands are so good that she just might finish while you are hauling her down. It’s just not fair.

Penalty differential data compiled by Karl Hendela, all other data complied by the author. Graphs made by Shayna Goldman (@hayyyshayyy).