The New York Islanders had a less than spectacular season this year. They made the playoffs and made it to the second round, but when looking at the numbers there are still a few things to work on.
The New York Islanders finished the 2015-16 season on a relative high note. They got that second round playoff birth, but their playoff run screeched to a halt when the Tampa Bay Lightning won four in a row to bounce the Islanders from the post-season.
But the disappointment wasn’t just the playoff performance. The Isles winning the Stanley Cup was a possibility, but a longshot. The disappointment was the regression that the team seemingly went through. The driver for this disappointment is based on the team’s possession analytics.
As we know possession is the new buzz word coming out of the analytics community and for good reason. If you don’t have possession you certainly aren’t going to score a goal, and that’s the point of the game. To score more goals than your opponent. Having the puck increase the odds of the happening dramatically.
If you’re new to analytics, as most of us are, don’t worry, this isn’t going to be another dry lesson on the difference between the mean, mode, and median that you got in stats 101.
Loss of Possession
The New York Islanders finished the 2014-15 season 6th in terms of Corsi-for % (CF%), with 52.7%. Corsi measures the number of shots taken, either on net or not, and blocked shots. The percentage is based on the number team A takes in relation to all shot attempts in games they have played. So during the 2014-15 regular season, the Isles took 52.7% of the shots in games they have played.
The idea behind Corsi is that if you’re shooting the puck it’s because you’re in possession of the puck. Think of it as a base of 50. Anything above 50 is considered positive possession while under is negative. The higher from 50, the better.
Now contrast that 2014-15 CF% with this season. In 2015-16, the Islanders CF% ranked 18th in the league with 49.5%. The New York Islanders went from a team that drove play and keeping possession to a team that fell to the other side of the spectrum and had other teams dictate play. They became a negative possession team.
This isn’t just reflected in their Corsi rating either. The Islanders zone starts have trended negatively to their zone. Offensive zone faceoffs were down by 0.8% and defensive zone starts went up by a full percentage point between2014-15 and 2015-16. Just going to show how the ice tilted in the other direction this season.
A three-point drop in Corsi doesn’t sound like an awful lot, but in the NHL, a marginal change means all the world. In order for the Islanders to bounce back next season they need to find a way to find a way to gain possession and at least be a positive possession team.