One of the few positions where the Tampa Bay Lightning don’t seem to have an established hierarchy is which defender will run the point on the second power play unit. Last season, Mikhail Sergachev was the clear option. This season, the coaches appear to be interested in giving Ryan McDonagh a chance at some of those minutes.
McDonagh played on the New York Rangers power play for the final five seasons he was with the team. He ran the second unit for all but one of those seasons. Sergachev was a rookie last year and got those minutes with the Lightning largely because they didn’t have another offensive-minded defender. Anton Stralman is capable in that role but Sergachev was an obvious upgrade.
The Lightning acquired McDonagh via trade in the spring. During his time in Tampa last season, he didn’t see any significant power play time including during the playoff run. The coaches clearly preferred Sergachev in that role.
Something has changed since then. McDonagh split second-unit power play time with Sergachev in camp and that continued through the first few games of the season. The veteran got the bulk of the minutes in the first two games with Sergachev getting a chance in the most recent games including the 8-2 explosion against Columbus that featured four power play goals.
Four games isn’t enough time to learn anything about a power play. In fact, full seasons don’t give good samples. Players on the second unit typically see around 150 minutes of power play time in a season. For defenders who play 15-20 minutes per game at 5v5, that’s equivalent to 7-10 games of 5v5 minutes. Making decisions on 7-10 games seems absurd so similarly, we have to be careful drawing confident conclusions based on individual seasons of power play results.
That said, we can still dig into the numbers and try to get an idea of how Sergachev and McDonagh have played to see who is more likely to be successful in that role. Because we only have one season of data for Sergachev, the best we can do is compare that one season to the five years of data we have for McDonagh.
To start, let’s look at two key metrics from Evolving Hockey. The first is goals above replacement. GAR tells us how much better each player is than a replacement level player on the power play. The second metric is Regularized Adjusted Plus Minus (RAPM) targeting expected goals. Think of this as another all-inclusive rating of player impact on expected goals. Again, we focus specifically on the power play.
The reason for using the two metrics here is that GAR can be heavily impacted by shooting percentages and if we’re only looking at power play results in small results, we’re particularly susceptible to that effect. The xG RAPM mitigates that by focusing on shots. Using the two stats together gives us as well-rounded a picture as we can get with the limited sample.
The charts below show each of McDonagh’s seasons and Sergachev’s only season by both metrics.
What’s notable here is that by GAR, McDonagh has never had a season on the power play as good as Sergachev’s rookie year. Using the xG RAPM, Sergachev’s season was better than all but one of McDonagh’s. Interestingly, that big spike for McDonagh in 2016-2017 came in the only season where he played on the first unit in New York. Playing on the first unit gives a player much better teammates and it makes sense that he would get much better results.
Based on the numbers above, Sergachev seems to be the best candidate for those second-unit minutes. Even at age 19, he put together a season that is better than any that McDonagh was able to generate away from the top unit in New York.
To get more color around how each player impacts shot rates on the power play, we can use the heat maps from HockeyViz. On these charts, an area of dark purple indicates that the team got lots of shots from that area with the player on the ice and a green areas indicates less shots.
Let’s start with McDonagh last season in New York. Here we see that the Rangers got some good activity at the right side of the net and that reflects well on McDonagh. As a lefty, that’s the side of the net he would likely target with passes. We don’t see any particular concentration of shots at the blue line suggesting that he wasn’t taking many shots of his own.
Compare that to Mikhail Sergachev who turned the middle of the ice into a purple blob. We see a high concentration of shots from the center blue line, which is Sergachev himself firing at the net. We also see that concentration of shots feed right on down through the circles into the slot. Part of that is Sergachev sliding down into the zone to get better looks and part of it is his teammates getting opportunities from dangerous areas.
The contrast between the two heatmaps is stark. Again, Sergachev seems to be having a much greater impact. The previous chart that we looked at for McDonagh is representative of the seasons when he played on the second unit. But in fairness to him, we should also look at his best season for comparison. Below is the heat map from his 2016-2017 season when he ran the top unit.
This pattern reflects more positively on him. The Rangers have multiple areas of high density including a nice blob from directly in front of the net to the left faceoff dot.
The question for the Lightning coaching staff is whether McDonagh can recapture the success he had in 2016-2017 while playing on the second unit in Tampa. That seems like a questionable bet at best considering that we have four years of data where he played on the second unit and achieved more modest results.
Taking into account all the available information, Sergachev seems to be the best fit to run the point for the Lightning’s second power play group. His results in his rookie season were better than any McDonagh has achieved under similar circumstances. Sergachev is at a point in his career where he is likely to improve rapidly while McDonagh is not.
On most teams, Ryan McDonagh would be a no-brainer to get power play time. But this Lightning team has Victor Hedman, Mikhail Sergachev, and the forward depth to run four forwards on both units. That means they might not have space to get the veteran many minutes with the extra skater. Instead, he’ll likely have his biggest impact at 5v5 and on the penalty kill.
Having lots of options gives the coaching staff flexibility and is a sign the organization built a deep roster. It also creates difficult decisions. Playing a young player over an established veteran in a crucial role can be risky. But Sergachev earned the chance to run the second power play unit with his play last season. And he should continue to do just that.