How do offsides in hockey work? (with pictures)

When you start to watch or play hockey one of the most important rules to know is the offside rule. The game does not make sense unless you understand it and it is one of the most common infractions in the game. 

What is an offside in hockey? An offside is a stoppage of play that occurs when an attacking player has crossed the blue line before the puck into the offensive zone. The key determination is the position of a player’s skates as they will be considered offside if both skates are all the way over the blue line before the puck enters the zone. 

The offside rule has many nuances to it. Let’s explore the basics and then get into all the finer points after that.

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What is the blue line for in hockey?

The hockey rink is divided into three zones: a defensive zone, neutral zone and offensive zone. 

The lines that separates the rink into these three zones are the blue lines.

The key purpose of the blue line is to stop players from entering into the offensive zone before the puck has crossed the line. This is to prevent the offence from getting too much of an advantage over the defence in play.

Without the blue line it would be too easy for the forwards to get in behind the defence on the attack.

Therefore, A player is not allowed to enter into the offensive zone before the puck has crossed the blue line. Now the key determination of whether a player has entered into the offensive zone is if the players skates have crossed the blue line before the puck.

It is okay if the players stick or head or body or one skate has gone over the blue line as long as the puck beats both player’s skates over the blue line.

How does the offside rule work?

What to watch for? When the game is played out you will see one player carrying the puck over the blue line and one of his teammates trying to time himself to go over the blue line at the right time and not go offside.

What this looks like is that the player without the puck will have one of his skates on or above the blue line while the player with the puck will be crossing the puck over the blue line with his stick while his skates are further back. So essentially, the player without the puck will enter the zone (or his skates) before the player with the puck. 

Another trick to watch for: straddling the line. A player will skate along the blue line with one leg in the attacking zone and one leg in the neutral zone. He is not considered in the zone until both skates cross the blue line.

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What happens when a player goes offside?

The linesmen is the official who is charged with the task of determining if a play is offside or not. When a play is considered offside they will blow their whistle and an offside will take place at one of the two faceoff dots closest to that blue line in the neutral zone. 

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When has the puck determined to have got into the zone?

The puck has crossed into the defensive zone when the entire puck has crossed the entire blue line. This means that you should be able to see some of the white ice between the edge of the puck and the leading edge of the blue line.  When that has happened other players on the offensive team are now permitted to enter into the zone.

What is a delayed offside?

The NHL is always concerned and leans towards trying to keep the game flowing with as few whistles as possible, and this applies to offsides as well.

So, if the puck enters into the zone in a manner where a player is offside but the puck has been recovered by the defensive team and they are in a position to bring the puck out of the zone the linesmen will raise his arm to signal a delayed offside. 

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It is a delayed offside because the whistle will not be blown and the player(s) that are offside will now be given a chance to exit the offensive zone before they can re-enter to try and gain possession of the puck. All of the players must be exited from the zone before they can re-enter.

As well, if the defending team clears the puck into the neutral zone the offside will then be neutralized and play will continue as normal. 

What happens if the puck is cleared out of the defensive zone?

Inversely, the puck is said to have left the zone when the entire puck has crossed the back of the blue line and into the neutral zone. When this has happened, all of the players from the offensive team must exit the offensive zone and have the puck cross the blue line again before they are permitted to enter the zone. 

This is why you will see teams simply try and get the puck out of their zone and past the blue line. They know if they can get it over the blue line all of the offensive players will have to leave the zone, and the offensive pressure will be momentarily taken away.

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When a defensive player has a chance but fails to clear the puck over the blue line it usually causes big problems for his team. So many goals result from players turning the puck over at their blue line and not getting the puck out, which results in a quick counterattack against.

2021 update to the offside rule

For the start of the 2021 season the NHL updated the rule so that a player is still counted as being on side as long as one of their skates is either touching or above the plane of the blue line.

The old rule stated that at least one of the skates had to be touching the blue line to be considered onside. However, with the introduction of coach’s challenges to offside (see more below) there were too many goals that were being taken back because of players who lifted their skates off the blue line milliseconds too early, which had no impact on the play that developed into a goal.

Therefore, the NHL determined that it would be good enough if the trailing skate was simply not passed the blue line and that the player would be onside and have not crossed into the offensive zone as long as the skate was above the blue line.

Why do they have offsides? The history of blue lines and offsides in hockey 

When the NHL was formed in 1917-18 there were no lines on the ice (except for the goal lines). The blue lines were not put into the NHL until the 1918-19 season, although the Pacific Coast Hockey League was using them.

The first seasons of the NHL also involved no passing forwards – only backwards! Yes, the first season of NHL hockey looks very different than it does today. 

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Scoring in the early NHL was difficult and the trend become lower and lower scoring games. To counteract this the NHL slowly adopted forward passing and in 1928-29 forward passing was allowed in all three zones of hockey.

However, the unintended consequence of forward passing was offensive players hanging out deep in the offensive zone waiting for a long pass while the puck was at the other side of the rink.

The NHL did not like this development or the style of play that resulted from it. So to give the defensemen assistance in stopping the attack and to make sure that the forwards would have to come back and not ‘cherry pick’ in the offensive zone they introduced the offside rule. 

What is the offside challenge?

When a goal is scored the coach from the opposing team may use a coach’s challenge to ask for a video review to see whether the play that resulted in the goal was actually offside before the goal was scored.

If the video review determines that an offside had proceeded in the play before the goal, then the goal will be disallowed. If the video review determines that the goal is good then the team that challenges the call will be assessed a minor penalty.

The following plays are not considered offside:

  • Defending player shoots the puck out of the zone and the puck hits a defending player and comes back into the defensive zone – all of the offensive players will be deemed onside
  • If an opposing player carries or shots the puck back into his defensive zone while an attacking player is in the zone it will not be considered offside. 

The NHL determined that too many goals that should have counted were being called back because of offside challenges, because a player had lifted there back skate milliseconds early.

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The league has amended the rule so that the skate has to either touch the blue line or simply be above the blue line. This should keep the spirit of the original rule while still allowing the same flow of play that we are used too. (And, hopefully keep a lot of those goals on the board).

Personally, I have always hated coach’s challenges for offsides – whether it is the team I am cheering for or if I am just a neutral observer. There are so many goals that have been called back from a play that was determined offside 30 to 45 seconds earlier. The offside had no bearing on the goal, and the call was more about the technology used and not the actual competition on the ice.

This is the right call to make and now I am more confident that there will be way fewer offside challenges.

What if a puck bounces off an official into the defensive zone while an offensive players is in the defensive zone?

If a puck bounces off the official and back into the defensive zone it will be considered offside if any player from the offensive team is in the defensive zone. A faceoff will then take place. 

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