By Leon Lifschutz | Follow me @BruinsBreakdown

Now that we impressed our friends with our commentary on the Bruins’ forward group, it’s time to rub in our smarts (ahem, prove to them our nerdiness) with a discussion on the Bruins’ defenders. We will again perform an investigation looking at individual expected goals (iXG) in comparison to actual goals scored (goals or G). As we learned in our investigation of the forwards, expected goal models provide a value for each shot based on location, type, and other variables. The advanced statistic is also an informative tool in predicting future team and individual success.

In post-season remarks, head coach Bruce Cassidy discussed a lack of offense from the back-end as an issue for the team. He shared in his comments that it’s an area that the team needs to improve in the coming campaign. Let’s dig into the numbers for the defenders (all who played 19 games or more) to get a sense of the situation and to figure out if, and how, the Bruins’ bench boss can coax more offense from his backline.

Bruins defense actual versus expected goals from 19-20 season pic.twitter.com/yaQAVeyBAi

— BruinsBreakdown (@BruinsBreakdown) November 20, 2020

General Observations

While the Bruins do finish near the top of the league in offense, they are a defense-first team. The team suppresses opposition shots and opportunities as well as anyone in the league. This emphasis may be a reason for the relatively middling number of goals produced by their defenders over the course of last season. From a talent perspective, most players finished at a reasonable rate as we see only Charlie McAvoy and Matt Grzelcyk fall minimally below the expectation line. This suggests the Bruins defenders are not generating enough goal scoring opportunities. To be clear, that isn’t to say they aren’t contributing to the build-up of opportunities, they are just not the ones taking those shots. (Note: Play sequence and build up contribution, an analytic well-developed in soccer, is in its infancy in hockey but could provide great insights in the future). The reasons for this could range from the team’s style of play to having personnel who are not best suited to creating their own offense. Identifying the cause will be key for Coach Cassidy in creating solutions.

Torey Krug

Say what you want about Torey Krug but he is clearly a top-20 defenseman in the league from an offensive standpoint. He finished eighth in points (49), tied for 20th in goals (9), and 19th in individual expected goals per 60 minutes (0.35 iXG/60). As is evident in our original scatterplot, he generated and finished chances at rates much higher than his Bruins’ teammates last year. The powerplay was an important source of his offense but not as overwhelming as sometimes is thought. Of his nine goals, two came on the man advantage. Of his 7.19 iXG, 3.32 came via the powerplay. Krug still led the team’s defenseman in scoring at 5v5, with Grezlcyk and McAvoy trailing slightly behind the departed blueliner. Krug’s offensive production will be missed, most notably when the Bruins have the extra skater.

My model loves Torey Krug and his power play prowess, but probably overvalues that on a new team now that he doesn’t share the ice with Boston’s three superstars. Should still be able to live up his new deal.https://t.co/foNQALGfjS pic.twitter.com/d6nYX3C2Ep

— dom luszczyszyn (@domluszczyszyn) October 10, 2020

Charlie McAvoy

When McAvoy burst onto the scene in 2017-18 and produced 32 points in only 63 games the offensive expectations skyrocketed. Since then, the Long Beach, NY native has posted seasons of 28 and 32 points and posted a career-low five goals this season. While McAvoy may never put up video game numbers on offense, there is some room for optimism he can build on his totals. First, he received limited powerplay time this past season spending just over 90 minutes with mostly the second unit to Krug’s more than 235 minutes with the top group. Expect his minutes on the powerplay, and quality of linemates, to increase substantially this coming year.

McAvoy has improved his number of opportunities each year but unfortunately experienced a career-low shooting percentage in 2019-20. With more powerplay time and a regression to a higher shooting percentage, the soon to be 23-year-old should post career highs in goals and points. It should also be noted that McAvoy has shouldered heavy defensive responsibilities with a 40-something Zdeno Chara during most of his career. It will be interesting how Cassidy utilizes his star defender and who he chooses as his partner this coming year.

Brandon Carlo

Serving as the defensive conscious on the second pair the last couple of seasons, Carlo has produced limited offense. Nothing in Carlo’s past or style of play would necessarily suggest that he should be a player relied upon for offense either. As such, he has never eclipsed more than ten minutes of powerplay time in a single season. Carlo has improved the last two seasons at getting the puck to the net and getting up in the play. His generation of opportunities is average for an NHL defenseman. His finishing ability this past year, and even more so over his career, has proven below average. If Carlo can refine his play just a little, and exceed expectations in his finishing ability, it would be a huge boon to the Bruins’ offensive efforts but they shouldn’t count on it.

Matt Grzelcyk

Grzelcyk may be the biggest key to replacing Torey Krug. A player with similar size, skill set, and style, the Bruins have made a big bet that the Massachusetts native can make up for a significant portion of Krug’s offense at a cheaper cost. The Bruins’ success this year feels like it could hinge on how prophetic that statement is, fair or not. While it’s important to qualify the following with the fact Grzelcyk has yet to regularly matchup against higher lineup players there is significant room for optimism in the underlying numbers.

At 5v5, Grzelcyk produces almost identical iXG and shot generation to Krug. He does a masterful job of getting up in the play with his excellent skating. On the powerplay, his numbers significantly trail both Krug and McAvoy. However, he is an apt facilitator on the powerplay, numbers that don’t show up as well in this study. The one big cause for concern, Grzelcyk’s shooting percentage is not good. His career average comes in at 3.5% compared to 5% for Krug and 7.4% for McAvoy. At 26, Grzelcyk is not likely to turn into a scorer but with increased ice time and powerplay opportunities he should be able to drive play and help create opportunities at a high rate.

Conclusion

The Bruins may be able to make up for some of the offense left behind by Torey Krug. Increased opportunity for McAvoy and Grzelcyk on the powerplay should increase their numbers with McAvoy, statistically speaking, the most qualified to take on the heavy lifting. A player like Carlo will need to chip in just a little more. The Bruins may additionally rely on several unproven players with little data such as Jeremy Lauzon and Connor Clifton to play regular minutes and contribute on offense. Lauzon showed offensive upside in Junior but has yet to produce much at the professional level. Clifton has had a couple of strong offensive seasons with Quinnipiac and Providence but has not produced consistently throughout his career and has shown little offense in his limited time with the big club. Other young players like Jakub Zboril and Urho Vaakanainen have also shown minimal offense potential at the pro level after being drafted with hopes for upside in that department.

Based on this analysis it would be irresponsible to expect improved offensive numbers from the Bruins defense next season. Their personnel suggests a group that won’t hurt the forwards but shouldn’t be expected to pot a lot of goals. If Coach Cassidy would like his defenders to increase their offensive output he will need to make changes stylistically. He will need to encourage his defenders to get up in the rush more than they currently do. He will also have to create more position-less hockey in the offensive zone allowing his defenders, a group of strong skaters, to roam the zone and find open areas. He will have to do so while ensuring that the Bruins don’t lose their identity as a league-leading defensive unit who stifles most opponent’s opportunities before they even start.