Sports Rules

Tagging up: where the in-air rule stops applying

The exception inside the exception. To clear a delayed offside the skate must contact the blue line — being above the plane is not enough.

NHL · Rule 83 — Off-side

Offside

Not tagged up: the delayed offside stands.

How it got there

  1. 1.What decides it

    Skates, and only skates. The stick does not matter, and neither does the body — a player leaning over the line with the puck on their stick is onside if their skates are back.

  2. 2.Tagging up on a delayed offside

    The 2021 allowance for a skate in the air does NOT apply here. To negate a delayed offside the skate must contact the blue line — being above the plane is not enough. This exception is the single most commonly missed part of the rule.

  3. 3.Where the trailing skate is

    decided it

    In the air at -4.0cm. Airborne does not count for tagging up, however far back the skate is over the line.

Read before relaying this

  • Read this

    Skates decide it, not the stick and not the body

    A player can reach across the line with their stick, lean over it, or carry the puck ahead of themselves, and remain onside so long as their skates have not preceded the puck. This is the opposite of soccer, where the foremost scoring part of the body is exactly what is measured.

  • Read this

    Since 2021 a skate in the air can still be onside

    The blue line is treated as a plane extending upward from its leading edge. If the skate has not broken that plane when the puck crosses, the player is onside — whether or not the blade is touching the ice. The change was made to stop offside reviews turning on pixel-level judgements about ice contact.

  • Note

    The picture freezes when the puck crosses, not when the player does

    Positions are judged at the moment the puck crosses the leading edge of the blue line. A player already deep in the zone is not offside if the puck got there first.

  • Read this

    Applying the rule is the easy half

    This computed a verdict from a skate position you supplied. In a real review the argument is entirely about that position in the frame the puck crossed — which is why the rule was changed to remove one of the two things that had to be judged.

Change the inputs

Use the form on the home page to move a position and watch the verdict move with it, or call the API or MCP server. This page is also available as markdown.

Related calls

Not an official ruling and not a substitute for a match official. This works through published decision procedures from the inputs you supply; it cannot see the play, and the hard part of a real offside call is almost always judging the inputs rather than applying the rule. Refereeing judgement, video review protocols, and competition-specific variations are outside what this models. Rule texts belong to IFAB and the NHL and are not reproduced.