By Leon Lifschutz | Follow me @BruinsBreakdown
While the only numbers that really count at the end of a hockey game are how many goals each team scored, it can be informative to look at a variety of metrics. Sometimes these additional data points can help explain how events unfolded. In other instances, they can help us predict future outcomes. Perhaps, most importantly, they can help us sounds smart when arguing with friends.
For this exercise, we are going to take a look at Bruins’ forwards expected goals (iXG) in comparison with their actual goals (goals or G) during the 2019-20 NHL regular season. Doing so may provide valuable insights into player performance this past season and give us food for thought for the upcoming campaign. Expected goals models take into account a shot’s location, type of shot, and other circumstances such as rebounds to give each opportunity a value. The value is derived from average success rates over several seasons. While there are some factors missing, like accounting for slot passes or screens, it can be very accurate. A player who shoots league average in a given season should be almost on par with their expected goals totals. This can be a valuable metric as expected goals, evidenced in this Hockey Graphs piece, can be highly predictive of future goal output at the team and individual levels. With that in mind, let’s dig into the numbers to see what we can learn.
Bruins forwards actual versus expected goals from 19-20 season pic.twitter.com/G1oWAYPdV0— BruinsBreakdown (@BruinsBreakdown) November 20, 2020
The graph features all Bruins’ forwards who played at least 20 games. The diagonal line through the chart indicates where a player would be if their expected goals matched their actual goals. We can note fourth-liners and players with fewer games clumped at the bottom left. They produce less due to talent and opportunity. In most instances, they also finish at a lesser rate than their more talented peers. The most talented players both create and finish. The Bruins did a good job creating opportunities but they also benefited from finishing at higher rates than most teams, evidenced by their more than 36 goals above expectation. While sometimes this can be a bit of luck and means a team is bound for regression, the Bruins high-end talent suggests it is sustainable.
David Pastrnak, if you haven’t heard, is an elite player. What makes him special is his ability to find opportunities and finish them. Pastrnak was third in the league in iXG and tied for 23rd in shooting percentage. The combination led to sharing a Rocket Richard trophy with Alex Ovechkin. The Czech winger is not afraid to shoot but he rarely wastes shots, first positioning himself in opportune spots to score. Credit for this needs to be shared with his linemates who are sublime at finding 88 off the rush and in soft spots in the offensive zone. Pasta’s ability on the powerplay should also be noted. His iXG is likely lower as the models do not value his usual spot at the top of the circle with the man advantage as they should. If Pastrnak can continue to create chances and finish them at this rate, the Bruins should regularly outperform the models through his prime years. He is an example of how integral an elite player is to driving team success.
The Bruins and Jake Debrusk just came to terms on a two-year bridge deal worth $3.65 million annual average value, a length and number we nearly hit perfectly here at BNG. There is still some debate around Debrusk’s ceiling as a player. An exercise like this can help answer that question as we examine the 24-year-old left-wingers’ past and potential future performance. Debrusk has posted seasons of 16, 27, and 19 goals despite never playing more than 70 games in a season. But the question remains, is Debrusk a 20-25 goal player as he enters his prime, or is he capable of regularly surpassing 30 markers a year.
Our scatterplot shows us that Debrusk produced the fifth most iXG on the team. However, accounting for iXG per 60 minutes of ice time, Debrusk moves up to third. Debrusk has increased his iXG each season in the league. So why did his actual goals drop? In his 27-goal season, Debrusk posted a shooting percentage of 17.31, well above his other two seasons which lie between 11 and 12 percent. Debrusk’s shooting talent is not equivalent to Pastrnak’s, suggesting he had a little bit of luck in his sophomore season scoring on a higher percentage of shots than we should expect from him moving forward. Debrusk is a strong player who can drive and finish opportunities at an above-average rate, just not an elite one.
Coaches love a player who can do the little things, play up and down the lineup, and in different situations all while positively driving play. Charlie Coyle does exactly that. This past season, the Massachusetts native produced two fewer goals than was expected of him but was nonetheless on pace for the second 20 goal season of his career. Over his career, he has produced 107.9 iXG while actually scoring 109 goals. Coyle is an average finisher but creates enough opportunities he can be counted on for roughly 15-20 goals a season. Coyle can be counted on to keep doing the little things along with some secondary goal scoring. Also, he is pretty solid at rock, paper, scissors!
Anders Bjork is signed to a three-year contract with an annual average value of $1.6 million. The oft-injured winger has yet to get any rhythm at the NHL level but the Bruins are betting on him being a top-9 forward once he does. Our exercise, though, gives us some cause for concern on how this one might play out. Amongst regular forwards this year Bjork ranked 11th in iXG per 60 minutes just edging out Sean Kuraly. His previous stints with the big club did not fare much better, though the Notre Dame product did see an uptick in underlying numbers when riding shotgun to Coyle. Bjork outperformed expectations this year. The only way he does so again is if he plays minutes up the lineup and continues to finish at an above-average rate. If even just one of those doesn’t happen, the Bruins have an expensive fourth-liner.
The Bruins forward group produces and finishes at above-average levels. Some of the numbers are inflated by the performance of their elite top-end talent. The Bruins will need a player like Debrusk to continue his developmental curve increasing his opportunities and continuing to finish at above-average rates. Coyle will need to continue creating opportunities and hope he regresses to average, or above, finishing a few more times than this past season. The Bruins will also need lower of the lineup players like Bjork to create more opportunities and at the very least finish at an average rate. But with their current talent pool, and the addition of Craig Smith, this group should remain towards the top of the league in goals.
Producing offense from the Bruins backline might be another story. Join us next time as we take a deep dive into the Bruins defenders’ actual versus expected goals.