# Line “Ruffling”, or Line Chemistry, and Its Impact on Winning

It feels like constant line juggling would make it hard to stay consistent and therefore have success in the NHL. Is that really the case?

Oh that sweet, sweet line blender.

I guess I should start by saying many fans don’t find it to be too sweet, especially when it isn’t to their preferences. After all, they ordered a peanut butter and banana smoothie and a few drinks in it turned into some green kale and cucumber garbage. That isn’t what they wanted at all.

While injuries have forced some of it, Lindy Ruff has “Ruffled” up the lines quite often this season. We aren’t talking a game-to-game basis either, it is almost period-to-period at this point. I’ve seen quite a few fans who are just over it, saying it’s impossible to stay consistent and find chemistry when players are constantly being juggled around.

I’ll admit, I’ve been one of those fans in the past. I didn’t always agree with the line shuffling but I really didn’t know why. Then I wondered, how much does the consistent line shuffling really impact the outcome of games and seasons? Let’s take a closer look at it.

The following line combination data is at 5v5 and courtesy of corsica.hockey. Man-games-lost for forwards data courtesy of @LW3H on Twitter and nhlinjuryviz.blogspot.com

## Line Combinations and Winning

We will start with the amount of forward line combinations a team uses and how it relates to winning, if it all. I went back and looked at the past three seasons so this data set will include 2013-14, 2014-15 and 2015-16.

Here is a simple chart (you should be able to click on the chart to make it larger) detailing what we are looking at. The X-axis tells us how many different line combinations accumulated at least 50 minutes of 5v5 play for a particular team. The Y-axis simply states how many points that team ended up with at the conclusion of the regular season.

I’ve circled the three Dallas seasons to make them stand out. As you can see, the season in which Dallas used the highest amount of different line combinations is the season that the Stars finished with the most points.

In fact, teams that used an above average amount of different line combinations actually finished with more above average seasons than the teams who used fewer line combinations.

In the graph above, the two top quadrants represent the above average teams. The right quadrant tells us who used an above average amount of different line combinations and the left quadrant tells us who used the fewest. 26 teams ended up the top-right quadrant while just 24 ended in the top-left.

While that certainly doesn’t tell us “more line combinations = more winning”, it does tell us there isn’t a strong correlation either way.

It isn’t crazy to think that injuries would force a coach to use more line combinations throughout a season, is it?

Again, a pretty surprising development.

The teams that lost an above average amount of forward man games used the fewest line combinations more often than not.

A few things could explain this. Maybe a coach sees his oft-injured lineup and decides that he wants as much consistency as possible. Lengthy injuries can also be planned for a little more compared to sporadic absences, allowing a coach to keep the same combinations while also losing a lot of man games.

Also, perhaps the coach with a healthier lineup wants to play around with many different combinations before landing on the right one. There are certainly factors that can explain the above chart but to me, it was still quite interesting to find out.

## Putting it Together

Now let’s have a look at everything together.

That is correct, nothing makes sense at all.

Obviously injuries can be offset by depth and the amount of line combinations you use isn’t going to decide your season. Ultimately, it comes down to the talent of the personnel and how they execute a system.

With that being said, it is hard to meaningfully draw the “line juggling has a negative impact on chemistry and therefore winning” conclusion from looking at the data available to us.

While I will be diving deeper into the subject of line juggling in the coming weeks, I felt this was a good place to start. Later on, I will look at how line juggling potentially impacts young players versus veterans, the development of players and take a look at defense pairings as well.

After looking at this, it’s tough to put any wins and losses on Ruff’s consistent line shuffling. We’ll see if it has any negative impact on other areas of the team in the next few weeks.