Examining the Seven Defencemen Approach

Since taking over as the Ottawa Senators’ head coach, Guy Boucher has made his style known around the league. His neutral zone trap continues to frustrate stars around the league, as the same system took the Sens all the way to the conference finals. It’s been a key component of Boucher’s coaching style, one that he’s thoroughly developed throughout his coaching career.

One unique aspect of Boucher’s style has been his willingness to play eleven forwards and seven defencemen, as opposed to the typical twelve-and-six approach. The Sens’ amount of depth on defence compared to forward has played a big part in making this possible, although Boucher’s shown no hesitation to go this route when making lineup decisions.

Since November 26th (the cutoff date for all data in this article), the Sens are one of only two teams to play 500+ minutes using seven defencemen. The Tampa Bay Lightning are the other, with 17 of their 23 games spent employing the extra blueliner. Ottawa’s split theirs evenly, with 11 games played using each formation.

The strategy has been nullified recently with both Chris Wideman and Mark Borowiecki going down with long-term injuries, although that likely won’t stop Boucher from switching back once one of them return.

At first thought it seems like this approach may harm the team. The forward corps becomes tired quickly, and it messes with what would instead be solidified line combinations.

As unconventional as it may seem, is it effective? Could it be harming the team? Using data from the 2017-18 season thus far, we might be able to uncover some answers.

Eight teams have played at least 100 minutes so far using a roster comprising of seven defencemen. On top of Ottawa and Tampa Bay, the list also includes Columbus, Detroit, New Jersey, Anaheim and both the Rangers and Islanders. This gives us somewhat of a sample size to work with, although it’s still worth being cautious when proceeding with  what amounts to under 50 games of data.

The following chart shows the difference between when a team is playing with seven defencemen compared to six. A higher number means that they play better with seven defencemen. The two stats used are Corsi percentage, and expected goals percentage.

Contrary to my expectation, it appears that playing seven defencemen may help. The only team to be affected negatively in both Corsi and expected goals is Columbus, while four of the eight teams are dually affected positively. This includes the Senators who see a slight bump in Corsi (47.49% to 48.34%) and expected goals (48.35% to 48.65%). Again, it’s worth being cautious about the sample size, although there appears to be an immediate trend.

Although there’s still plenty of room for uncertainty in this analysis, it’s good to see that Guy Boucher has potentially found a competitive advantage. While going 11/7 may not be the best option for every team, it appears that there’s no immediate harm in making the switch. There may even be a benefit.

11-7 data from Natural Stat Trick, Corsi and Expected Goals from Corsica.