How to check offside on your own match video

The offside rule in plain words

Offside is Law 11 of the Laws of the Game. A player is in an offside position when, at the moment a team-mate plays or touches the ball, all of these are true:

• They are in the opponents' half. Level with the halfway line counts as their own half.
• Some part of their head, body or feet is nearer the opponents' goal line than the ball.
• That same part is nearer the goal line than the second-last opponent.

Three details decide most arguments:

• Level is onside. Level with the second-last opponent, or with the last two, is not offside.
• Hands and arms do not count, for attackers or defenders. The arm starts at the bottom of the armpit, so a shoulder counts and a hand does not.
• The goalkeeper is an opponent like any other. Usually the keeper is the last opponent and the second-last is a defender. If the keeper has come out, the last two can both be outfield players.

A position is not an offence

Being in an offside position is not an offence by itself. The referee only penalises it when the player becomes involved in active play: playing or touching the ball, blocking an opponent's view or movement, challenging for the ball, or gaining an advantage from a rebound or a save. There is also no offside straight from a goal kick, a throw-in or a corner kick.

So a video can settle where the players were. Whether the attacker was involved is a judgement you make by watching what happens next.

How to check offside on your own match video

1. Find the moment the ball is played

   Not the moment it arrives. Step through the video picture by picture and stop on the first picture where the passer's foot touches the ball.

2. Find the second-last defender

   Look at every defending player in the picture, keeper included, and pick the one second nearest to their own goal line. It is easy to pick the wrong one when the keeper is off their line.

3. Find the attacker's most forward scoring part

   Head, shoulder, knee or foot, whichever is nearest the goal line. Not a hand or an arm.

4. Do the same for the defender

   Their most forward part towards their own goal line sets the line.

5. Draw the line across the pitch, not across the screen

   Unless the camera stands exactly on that line, a line across the pitch looks slanted on the picture. Use the painted lines to see which way the pitch runs at that spot. The edge of the penalty area is a good guide.

6. Decide if the gap is big enough to call

   If the two players are level or nearly level, say so rather than guess. The next section explains why.

Why some calls are too close for a club video

• The moment falls between two pictures. A video is a series of still pictures, usually 25 or 30 a second. A sprinting player covers a stride of ground in a handful of pictures, so the exact moment the ball left the boot is often between two of them.
• The angle hides depth. From one camera you see the players' feet clearly, but how far a shoulder leans forward is hard to judge.
• Players far from the camera are small. A few pixels can cover a lot of grass on the far side of the pitch.

Professional VAR uses several cameras and fast frame rates and still has a margin. On a single club camera, a clear gap can be called with confidence. A gap of a few centimetres cannot, and pretending otherwise teaches the players the wrong lesson.

Filming so offside can be checked later

• Film from high up, near the halfway line. The higher the camera, the less players hide each other.
• Keep the back line in the picture when an attack builds. A defender out of the picture cannot be checked.
• Do not zoom in too tightly on the ball. Wide enough to see the last defender beats close enough to see faces.
• Use 50 or 60 pictures a second if your camera offers it. More pictures put you closer to the moment the ball is played.

More in how to film a football match.

Checking offside in SeeKick

SeeKick's VAR offside check works on the paused video of your own match, in the match viewer where you already watch it:

• Pause on the pass and press O. Click the last defender, then the attacker. Or let SeeKick pick both.
• The offside line is drawn on the video across the pitch, following the painted lines, so the camera angle does not fool you.
• You get one of three answers: offside, onside, or too close to call. It only calls offside or onside when the gap is clear on that video.
• A 3D replay shows both players from the side, from behind or from above, like the replay on TV.

It is a tool for coaches and analysts, not for referees. It checks the picture you paused on, it can only count players who are on screen, and whether the attacker was involved in play stays your call.

Questions