Does Cassidy Mix Up His Forward Lines Too Often? (Part 2)

(Photo Credit: SinBin.vegas Photographer Brandon Andreasen)

Following the game on Long Island before the break, Bruce Cassidy said of his line combinations, “we’re always going to change if they don’t work.”

He walked it back in the next sentence as he remembered the plan early in the season to allow the lines a few games together, but if my high school psychology teacher taught me anything it’s that the first answer is usually the one a person believes.

This helped guide my next phase of research on this topic, which is centered around how each line’s performance has impacted Cassidy’s willingness to either keep it together or break it up. (If you missed Part 1, it’s here.)

I’ll admit now that this segment of research does not answer the question as to whether or not the Golden Knights would be more successful with less line shuffling, but it absolutely shows the practical process that has led Cassidy to switch his lines as often as he has this year.

VGK have used 46 different forward line combinations this season. I went through and compiled the stats for each trio when they are on the ice together. This includes not only games in which they started together, but anytime the three players have shared the ice at 5-on-5 this season. (A full sortable table is available at the end of this article.)

It’s a lot of data, I know, but just focus on the frequency of colors from the top to the bottom. Near the top, we have a lot of green, which means success. Towards the bottom, we start to see a lot more red, and deep red in many areas.

Most of the lines that have played a bunch together have enough underlying stats to make a coach feel comfortable keeping that line together. Meanwhile, most of the single-game lines have struggled.

That looks like a clear indication that line chemistry exists with the Golden Knights. The more a line plays together, the better off they are. However, this data was not available to the coach at the time of his decision.

51 games in, we have stats for how that line has performed over the course of all of their games together. So, it’s easy to see that The Misfit Line or the Stephenson-Eichel-Stone line have been strong over the course of the year. But, as the head coach, you only have the data in front of you at that moment. When a line plays its first game together, you have to make a choice based on that game, and that game alone, if you are going to keep them together. This is where we really get a read into Cassidy’s decision-making.

Here’s a look at what each line did in their first game matched together this season. Note that this chart is ordered exactly the same as the last one. Again, focus on the color progression.

The progression actually gets stronger when just looking at the first game. And Cassidy spoke to instant line chemistry in a recent press conference.

Some guys right away they hit it off, they think the game the same way, and off they go. -Cassidy

Clearly, the Golden Knights’ coach believes what he sees on the ice. If a line has success, he’s much more likely to leave it together, if they don’t, he wastes no time taking it apart.

Of course, there are exceptions, but for the most part, if a line can’t click within the first 60 minutes of playing together, he won’t wait to try something new. And looking at how poorly some of those single-game lines performed, it’s hard to blame him for throwing them back in the blender.

You might look at the chart and say, but why did he leave some of the poor-performing lines together? And, on the same token, why rip apart the lines that did show out well in their first game? It always starts with performance.

For example, the line of Cotter, Amadio, and Kessel. Their first game was nothing short of a disaster. They started 100% of their dead-puck shifts in the offensive zone, yet got shredded in Corsi, Expected Goals, High Danger Chances, and were on the ice for a real goal against. The next game, Cassidy swapped Leschyshyn for Amadio. They were a mess too. So, he switched it back. They were still terrible. So, he went to Nic Roy. The results continued to be poor but slightly better than with Amadio or Leschyshyn. That line held for four games, but was immediately broken up when an injury forced changes to the top six.

This brings me to the other consistent reason for splitting up a line, injuries. Of the 16 lines that have played a single game together, seven were broken up due to a player returning or exiting due to injury the following game. For instance, the line of Cotter-Froese-Amadio played well, but in the next game they were no longer together. That’s because William Carrier was unavailable for the next game forcing a switch in the bottom six.

Finally, team result plays a part. Cassidy is much more willing to break up linemates following a loss than he is after a win. Of the 22 lines that played their first game together and were split up the next game, only three were after a win without a new player returning or leaving the lineup. Those three lines were Cotter-Leschyshyn-Kessel, Amadio-Roy-Kessel, and Rondbjerg-Leschyshyn-Rempal, three of the statistically worst lines VGK have seen all season.

So, to summarize, Cassidy leans on three factors when he decides to change his lines from game to game. The first is performance. If a line is good, they are more likely to stay together, if they are bad, they are probably coming apart. Next is injuries. When a player returns to the lineup or someone new goes out injured, a coach is almost always forced to do some line shuffling, Cassidy is not immune to it either. Finally, the last is result. When the team loses, you can expect changes.

Statistically, it really doesn’t prove whether or not he’s switching the lines too often, but from a practical standpoint, it’s hard to argue against any of his logic.

**All on-ice stats for this article are sourced from NaturalStatTrick.com.**

Chart 1 – Full Season Line Stats

Chart 2 – First Game Together Line Stats