Florida Panthers Possession Check: An Early Season Corsi Study
After 13 games played, an early glimpse at possession trends for the 2014-15 Cats
As LBC's stats guru Shane will (quite correctly) tell you, early season analytics generally have a lack of reliability due to small sample sizes. I understand this. I agree with this, it's all true. But nonetheless, I figure there's got to be something I can use all this recently mined data for, and by jove, I started working on it. I have been quietly tracking one statistic through this young season, not really to point to a number and say this is what that player is doing, but to establish trends. That statistic is 5-on-5, all situation, Corsi For %.
For those new to this version of Corsi, an explanation can be found here, but basically, Corsi is a measure of all shots: including those on goal, those missed, and those blocked (hence, "all shots," eh?). The Corsi For percentage is a measure of the number of all of those shots "for" that player's team while they are on the ice, expressed in a percentage that may be compared to other players. In theory. the more shots "for" while a player is on the ice is determinative of how much time his team is spending with the puck in the offensive zone. More shots generally equates to more time with the puck, more time in the offensive zone, and more opportunities to score.
There are a multitude of factors that can cause adjustments in a player's Corsi For %, with two of the biggest being time on the ice (TOI) and zone start %. Those lucky Panthers that get to start more shifts in the offensive zone will typically get more shots off than those who must carry the puck 200 feet to even get that opportunity. It is equally obvious that players getting more ice time will in most cases get more shots than others that may see only 8-10 minutes of ice time per night. Defensemen typically log more minutes than forwards, which could mean they get more shot opportunities. Of course, that could also mean fewer shot opportunities over watered down minutes. This is what is meant when people say the numbers average out over an entire season, which brings us back around to the futility of small-number statistics.
All that said, I decided to watch how the Panthers were doing as a trend against the rest of the league, rather than a specific number. To keep things as simple as possible, I excluded zone start data and set a minimum ice time number for each way point on my survey. I don't want somebody who got 8-minutes of ice time but was on the ice for 3 shots-for during that time to skew the numbers (which is what happens when you include small ice time players with large ice time players). All the numbers I used were taken from www.puckalytics.com. I figure that if we look at this particular stat at various points in the season we will be able to see how members of the team are trending. We will be able to see who is at the top of the team and whether they can stay there. We can see how they compare to the rest of the league as games go by and whether they are falling off or picking up as their time on ice grows. We can also see how lineup changes and injuries are affecting certain players.
To establish a baseline to work from, I started after the Panthers first five games were in the books. After this point, I looked at the league-wide even-strength Corsi For %, using a 50-minute minimum of ice time (to exclude small ice-time wacky-stats), and found where the Cats were on that list. In that small sample, some Panthers put up some great numbers. I looked again at the seven-game mark (really just because I was unsure of what I was doing with these numbers yet). I checked in again at the thirteen-game mark. Below is a chart with where Panthers players who made the minimum time-on-ice for the respective number of games played fell in the NHL among players with that particular minimum ice time (more on that shortly):
|Name:||5 games||7 games||13 games|
To further explain the chart: Nick Bjugstad was 15th in the NHL after five games in 5-on-5 Corsi For % on that list of players who had 50-minutes or more of ice time. Jonathan Huberdeau was 17th; Brian Campbell was 34th; Aaron Ekblad was 61st; Scottie Upshall was 111th; Sean Bergenheim was 116th; Kuli came in at 205th; Jussi Jokinen was 224th; Willie Mitchell was 255th; Erik Gudbranson was 332nd; Brad Boyes was 341st; Aleksander Barkov was 354th; and Dylan Olsen was 395th. No other Panther player logged enough ice time to show up on the list.
On October 28th, I re-ran the list using 75-minutes of ice time as my minimum. The Panthers had played two more games than my first check (after five games), but there were some differences. Bjugstad still led the team but was now 11th best in the NHL at 5-on-5 Corsi for %. Huberdeau dropped to 39th; Campbell to 97th, Ekblad to 149th, Upshall moved up to 98th while Bergy got to 84th; Kuli jumped to 86th while Jokinen dropped to 292; Willie Mitchell also jumped, to 165th, while Gudbranson dropped to 350th; Brad Boyes saw an uptick to 239 and Barkov moved to 307th. Olsen dropped off the list with insufficient ice time.
Six games later, on November 13th, with the Cats having played 13 games, I again checked the list, this time using 140-minutes as minimum ice time. Some notable changes showed up. The trends show just how important Huberdeau is to Bjugstad. Huberdeau and Bergenheim dropped off the list after missing games: they no longer made the minimum required ice time limit. Bjugstad dropped down to 106th on the list. Upshall fell back to 127th. Brian Campbell moved to 48th, the highest ranked Panther; How special is Aaron Ekblad? The 18-year-old rookie is 82nd; How good a season is Kuli having? He moved up to 69th, while his partner, Willie Mitchell moved to 180th. How much did Jokinen benefit from being moved away from Barkov? He moved to 247th. Gudbranson dropped to 385th and Dylan Olsen to 400th as the two defensemen show the effects of tough competition and lots of defensive zone starts. How much did Barkov benefit from the Killer B's line reunification and a recent move to partner up with Kopecky and Upshall? He moved up to his best rank of the young season at 231st, while Boyes dropped back to 317th, with possible negative impact on Bjugstad in the San Jose game.
Obviously, there are problems with using just this data, such as the difference in number of games played at that point by the Panthers compared with other teams in the league, and the aforementioned zone start issues. There are also discrepancies in ice time among the Panthers who made the list- with Barkov missing time before the thirteen-game mark. But if nothing else, this gives us a base point to use to see how the team's players are trending. This also tells us who is getting the most ice time, and who is getting a lot out of that time.
Again, there was only a two game difference between the first and second check of the league-wide numbers, so this data is not inherently reliable. But remember- we are looking to see trends, and for the most part, the team was trending in a bad direction on this Corsi spectrum during the early season when the Cats gave up enormous numbers of shots against while shooting very little as a team. At that point some changes were starting to be made in the Panthers' forward lines.
The trend we see as of this thirteen-game sample is forwards falling off, while the defense looked tremendous. Does possession drive offense? Well, we see trending regression in Corsi For % at even strength for the forwards during a time period that saw the flu and injuries to Huberdeau, Barkov and Bergenheim scramble the forward lines. But the Panthers also were the top ranked team in the NHL at not giving up even-strength goals, so the defense's numbers are well reflected on the game results. Even with regression, Bjugstad is still the highest ranked Panthers forward on the list. The next highest rated forward for the team on that list is Scottie Upshall at 127th.
I have further benchmarks set for the season to check back in and see what we can learn, but as of now the numbers and trends reflect what we are seeing: Bjugstad is a beast, the defense is solid, Ekblad has been all that was advertised, and Huberdeau has been a real contributor this year.
Now the question becomes how those standings will change over two dimensions: within the team and within the NHL. We can easily determine who is getting the most ice time on the team, and more importantly, who is providing the most possession during that time when compared with their teammates. As ice time and number of games has gone up, the majority of the defense has moved up the Corsi For spectrum, which is a great sign. Is Barkov struggling with certain linemates? It looks that way.
The answers to these and more questions will come into sharper focus the next time we check in, as the Cats schedule gets tougher and the ice time and games played goes up. But for now, the Panthers are generally trending in good directions. With Huberdeau and Barkov back in the lineup our next check should reflect their impact, so we may be able to get an idea of how much those two players are contributing. I am no mathematician, and do not have anywhere near the comprehension my friend Shane does for the numbers, but I feel as though the trends are a poor man's means of determining who on the team is providing the largest positive impact over spans of time.