The Oilers Improvement in Possession Numbers and Expected Goals

The Oilers may have finished the 2015/16 season near the bottom of the league, but looking a little deeper into the stats we see that the club improved in a few areas that are critical for winning games. First, they improved their overall share of goals at even-strength, going from 40.46% last season, up to 45.38%. That's a significant jump, and was the third biggest change from the season prior across all 30 teams, behind Arizona and Florida. Goal share is obviously important, but we know that there is a lot of luck involved in scoring goals, with some teams riding higher than average shooting or save percentages to pad their goal-share stats.

Knowing that, it's important to look into a team's share of total shot attempts (i.e. Corsi For%) which serves as a good proxy for possession,  as well as expected goals, which measures shot quality and scoring chances as determined by Corisca Hockey. When it came to possession, the Oilers finished with 48.71% of all shot attempts (adjusted for score, zone and venue), good for 20th in the league, and up from 46.98% last season (26th overall). When it came to their share of expected goals, the Oilers made a significant jump from last season, going from a 43.32% share (28th league wide), up to 49.24% (20th overall). Below is a graph of the Oilers share of shot attempts (i.e., Corsi For%) over the past nine seasons, as well as their share of expected goals (xGF%).

The average for both metrics is 50%, something that the Oilers haven't reached as a season average. In 2015/16, they did, for the first time in over seven seasons, have a stretch of 25 games where they had a Corsi For above 50%. But that was short lived after Korpikoski started getting more ice time and young Davidson, who posted some excellent numbers, went down with a knee injury. Also worth pointing out (mostly for my amusement) that 2011/12 season where the Oilers made a noticeable jump when it came to possession and scoring chances in Tom Renney's second season as head coach. One of the many questionable moves by Steve Tambellini.

The Oilers jump in CF% (+2.44%) and xGF% (+3.66) in 2015/16 seemed high to me, so I looked into how they compared to the other 29 seasons. What I did here was find the five-year average of each NHL team's CF% and xGF% prior to this past season, and see what the difference was compared to their 2015/16 numbers. I figured this would give us a more accurate representation of each team, and give us a better look into which teams are actually off of their historical trends. This by no means is meant to rank teams in any way since some clubs like Toronto and Edmonton were expected to post higher differentials since they were so bad over the past five years. But it gives us a starting point for further analysis. Please note, teams are ranked by their xGF% change from highest to lowest.

Here we see that the Leafs, Oilers, Penguins and Blue Jackets made the biggest improvements from their previous five seasons' average xGF%. When it came to CF%, the Oilers ranked behind Anaheim, Toronto and Nashville, which was interesting to me as both the Ducks and Preds have had success in the past yet still appear to be improving. I was somewhat surprised to see Chicago and Boston where they are, as I thought they had a season that was consistent with their historical performances. Again, this isn't to say that they're bad teams, but they appear to have taken a step back.

What we also see when presenting the data like this are the teams that might be have some challenging days this summer. While some teams like Ottawa have made changes to their coaching staff, others like Vancouver and Colorado appear to be in a period of denial and don't appear to recognize that their clubs need major help and are likely to continue running their business as is.  These are exactly the types of teams worth exploiting in the trade market this summer, as they're clearly on shaky ground but haven't made necessary changes to their hockey operations department of coaching staff.