How do line changes work in hockey?

Hockey is known as the fastest game on earth, and line changes in hockey contribute to this. However, they are also a confusing part of the game: players coming on & off during the flow of the game at seemingly random times. Who comes off? Who goes on? How do they know?

How do line changes work in hockey? A player is allowed to change at a stoppage of play or while the game is still happening, which is called changing on the fly. Coaches are responsible for letting players know which line is out next, and generally keep certain players together. Each shift will last about 45 seconds.

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How line changes work in hockey

Let’s break down all the tactics and strategies for how an NHL team will make line changes during the game.

How a team is organized for line changes?

An NHL team during the game is made up of 12 forwards and 6 defensemen with two goalies (a starter and a backup).  

The forwards are broken up into four lines of three. So, each forward line has: Left Wing — Centre — Right Wing

The defensemen are broken up into 3 pairs: Left Defenseman and Right Defenseman

If there are no penalties, there will be three forwards and two defensemen on the ice at all times; or, another way to say this is: one of the forward lines and one of the defence pairings.

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The players are organized on the bench to sit in their groupings of players with the forwards on one side of the bench (closest to the opponent’s goaltender) and the defensemen on the opposite side of the bench (closest to their own goalie) — each in their line or pairing. From there, the coach(es) will indicate which line will go out and play, and which are the subsequent lines that are to follow after the previous lines/pairings are done.

Again there are two times that the players will make these substitutions: while the play is happening and at stoppages in play.

Line changes while the play is happening

The termed used for players changing while the play is happening is called “changing on the fly”. Changing on the fly is a necessary part of the game for two reasons: 1) to keep the flow going and 2) for the stamina of the players.

Most other sports require a stoppage in play before a player is allowed to substitute in, but not in hockey. This unique feature of the sport — where a player does not have to check in with a referee before coming on the ice or going off — is what allows hockey to keep so much of its flow.

If there was no changing on the fly, there would probably be more whistles, as teams would want to freeze the puck or stop play to allow tired players to come off the ice. It is not unusual to see hockey go 5 – 10 minutes without a stoppage in play.

The players also do not have the stamina to stay on the ice for more than 30 seconds to 1 minute. Considering how hard and intense NHL players play, they try to keep shifts short. If they are ‘caught’ on the ice for too long, their play usually starts to diminish and the other team can capitalize off tired players and create more scoring chances. Hockey is one of the greatest calorie burning sports. . Hockey is one of the greatest calorie burning sports. .

How they actually change on the fly

A player is allowed to change at anytime while the play is happening, however the player coming on is not allowed to come onto the ice until the player is within 5 feet of the players’ box. This results in a case where (for a few instants) both the player coming onto the ice and the one coming off will be on the ice at the same time.

However, if the substitution is not done correctly, it could result in a penalty. If the player comes onto the ice before this 5 feet, then a too many men minor penalty will be called.

In addition, when both players are on the ice, neither is permitted to touch the puck. If either of the players touch the puck (even within that 5 foot zone) the team will also be called for a too many men penalty.

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The coaches will run the benches and let the players know who goes on the ice and which forward line or defence pairing is up next. It then becomes the responsibility of the players to watch for the player they are to substitute off and go on for when they come off.

For instance, the centermen on the bench will be watching the centermen on the ice and when he is ready to come off, he will be the one who goes on. This goes the same for the left winger, right winger and both defensemen.  Teams will usually try to change as much as possible as units (in lines or pairings) but this is not always possible depending on how the current shift is going and may have to just switch off the positions one or two at a time.

Once the line has gone on the ice, the coach will indicate the next line to go on and so forth. The coach does make some adjustments during the game and may switch up the players playing on a certain line to try and create a spark.

Line changes during a stoppage of play

The much more straightforward time for the substitution of players and the changing of lines is after a whistle.

After a stoppage of play, with a few exceptions (that we will get to down below), a team is allowed to change any of their players on the ice. The team will usually change in lines and pairs, or an individual player may come off to get a line or pair back together.

There is a process to player substitution and it starts with the away team.

The away team must change its players first. The linesman will skate to center ice and hold his arm up while facing the away bench. This is the indication that they are to change lines (although, in practice this may start before the linesman has signalled). After 5 seconds, the linesman will lower his arm indicating that the line change time has come to an end.

The linesman will then indicate to the home team that it is their time to substitute players. The home team will then put on the players that it wants for the next shift.

Why does a home team get the last line change for substitutions?

The last line change is an advantage for the home team and, simply, it all has to do with matchups. It is an advantage for the home to change second because they can match up players they want to either defend or take advantage of offensively.

Many of the coaches are always looking at getting certain players out against other teams’ top players. This is similar to a manager in baseball wanting a specific pitcher to go against a hitter. For instance, in hockey, a coach often will want to get their best defensemen against the other team’s top forwards. Or, often a team will have a really good defensive forward line (forwards who are particularly good at defending against the opposing forwards) who they want to match up against the other team’s offensive line.

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Being the home team and getting the last change definitely helps to get favourable matchups for your team.  

Zone starts: Where a coach decides to start a line

A coach will also start certain lines more often based on the location of the faceoff zone. If the line is weaker, they will often get more starts in the offensive or neutral zone. The coach is willing to sacrifice some offence to make sure that they do not get scored against by having a sub-standard line start in the defensive zone.

As you look at the zone starts for amazing defensive forwards like Patrice Bergeron or Ryan O’Reilly, they will get a lot of defensive zone starts because they are so good at winning faceoffs and gaining possession of the puck so the puck can get out of the defensive zone as quickly as possible!

When are teams not allowed to change lines after a whistle?

There are times when a team is not allowed to change lines. The most notable is when the team has been called for icing the puck down the ice.

When a team ices the puck down the ice, they are essentially shooting the puck from their side of the red line to their opponents’ end of the rink. The NHL wants to discourage teams from doing this, as it could become a crutch to give a break to tired players (and it would make the play more choppy). So, this play is whistled down with the faceoff being held in the zone of the team that iced the puck. As well as the faceoff coming back to your zone, the team that iced the puck is not allowed to make a line change.

This can be a big disadvantage if a team has tired players on the ice. The other team still gets to change players so they can stick out fresh lines and if they win the faceoff, it gives them a big advantage at getting a scoring chance or two.


Have fun watching the line changes as you go to the games. There are few sports that allow substitutions on the fly, and it is one aspect of hockey that makes it truly great. It keeps the play fast, flowing and exciting!!!

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I am a lifelong fan who grew up in a major market (Calgary), and I have played, coached, and watched a lot of hockey!

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