I hear it from fans every time an NHL coach wants to reshuffle his lines.
"Don't split those guys up, they have great chemistry!"
"If we put him there, it will ruin the line's chemistry."
But how important is chemistry to a line's success?
There are thousands of potential definitions for chemistry as it applies to sports. I'll give you a simple one: Chemistry is a combination of familiarity and camaraderie.
Now, let's take a look at the positive factors regarding chemistry:
Playing on a line with the same skaters every night will create a comfort zone. If the three forwards know eachother's tendencies, they will be unpredictable and one step ahead of the defense.
That form of non-verbal communication cannot occur with three random players thrusting into action. There is a reason why the Spezza-Heatley-Alfredsson line has been one of the most successful lines in the NHL over the past three seasons. Familiarity breeds success.
However, does camaraderie breed success?
Certainly, a lack of camaraderie can ruin a team. It is one of the reasons why Sean Avery has hopped around the league, despite his energy and usefulness. Locker room cancer is always destructive, and sometimes to a great degree.
But are Spezza, Heatley, and Alfie friends off the ice? Does that even matter? If you took one of those players away from the Senators and put him on another team, would he suddenly become ineffective?
In my opinion, no.
The type of players who are put on a line has a far greater impact on effectiveness than the names on the back of the jerseys.
It's not important whether or not the players on a line get along with each other or like each other. It's important that their skills and abilities complement each others' games.
In other words, it doesn't need to be Jason Spezza, Danny Heatley, and Daniel Alfredsson playing together. The replacement player doesn't necessarily need to be as talented, but you better make sure that he provides skills that are similar to those of the player he replaces.
That can cause problems when there isn't a suitable player on the roster. The Anaheim Ducks are currently in such a situation in scrambling to find a partner for Ryan Getzlaf and Corey Perry. To do that, the "shutdown line" of Rob Niedermayer, Samuel Pahlsson, and Travis Moen has been shuffled around, much to the chagrin of some Ducks fans.
That "shutdown line" was one of the keys to the Ducks' championship in 2007. However, it is my belief that Todd Marchant would be a fine replacement player on that line. Splitting the three "traditional" members will not be an issue, since the replacement player brings similar abilities to the table.
To sum up—if a line that has been together for a while needs to be split up, don't immediately panic. Give the replacement player a chance, and see if the new line's effectiveness improves after a couple of weeks. If the players do not perform adequately after a good chunk of time, then panic.
Just stop worrying about whether or not they go on camping trips together over the offseason.
Bobby Russell is the Community Leader for the Anaheim Ducks on Bleacher Report. You can contact him, make fun of him for living in a warm climate, or add him to your lineup by going to his profile.