Let's assume for a second that a Linesman has Olympic sprint capabilities and incredible stamina and therefore speed to keep up with play is not a factor. Let's assume then that he is in perfect physical position every time to make a call for offside, i.e. perpendicular to the last defender (or second to last player bla bla bla) which I will refer to from here on as "the line".
Even with the above in place, I still think the job of calling offside is physically impossible for a human to achieve reliably. The Linesman has to wait until the ball is touched by the attacking side in order to then check the line, and in order to do this he simply has to rely on his eyes only. He cannot rely on sound as then he would not be confirming the person that last touched the ball in close battles. He simply has to use his eyes to confirm the last touch. By the time he has then re-directed his eyes to the line and attempted to identify attackers that are in an offside position, many players have moved in this supposedly small time window.
it only takes a split second to change your eyes position yes, but this is enough to alter the decision quite dramatically when during some extremes defenders can be running full speed in one direction and attackers running at full speed in the other. I suspect in the time taken to move ones eyes and lock focus on a possible offside offender, not just one yard, but 2 or 3 yards can be simply missed by the linesman.
After last nights Bayern/Real game, BT sports pundits were replaying the offside Ronaldo 2nd goal, whereby he was a good yard off side. One of the comments went something like "look, the Linesman is in perfect position looking down the line, how can he not see that is offside". I'll tell you how...watch it in real time and tell me you can tell it's off side. Make sure you watch the assister's boot until it connects with the ball which starts the through ball to play Ronaldo through, and then move your eyes to check if there is anyone offside. It's not possible.
Linesman are expected to do this in real time, seeing it once, when they can't always keep up with play, and are meant to interpret interference and whether an arm/half a torso is offside or not, all whilst looking in two places at the same time and running up and down a line at differing paces. It's not fair to expect them to get this right all the time. I've ran the line myself and have first hand experience of how hard this is with only 12 year old kids! Imagine Ronaldo pace lol.
I once watched a training video in a room full of coaches, and for a laugh, we were all asked to vote offside or onside on a demo video where you get a point of view of a Linesman on about 5 offsides. Needless to say the results were totally sporadic and mainly just guesses. The aim was to show you how hard it was/is.
Video assistance needs to come in whatever the cost, and I mean even if the cost is stopping play more often.
Even with the above in place, I still think the job of calling offside is physically impossible for a human to achieve reliably. The Linesman has to wait until the ball is touched by the attacking side in order to then check the line, and in order to do this he simply has to rely on his eyes only. He cannot rely on sound as then he would not be confirming the person that last touched the ball in close battles. He simply has to use his eyes to confirm the last touch. By the time he has then re-directed his eyes to the line and attempted to identify attackers that are in an offside position, many players have moved in this supposedly small time window.
it only takes a split second to change your eyes position yes, but this is enough to alter the decision quite dramatically when during some extremes defenders can be running full speed in one direction and attackers running at full speed in the other. I suspect in the time taken to move ones eyes and lock focus on a possible offside offender, not just one yard, but 2 or 3 yards can be simply missed by the linesman.
After last nights Bayern/Real game, BT sports pundits were replaying the offside Ronaldo 2nd goal, whereby he was a good yard off side. One of the comments went something like "look, the Linesman is in perfect position looking down the line, how can he not see that is offside". I'll tell you how...watch it in real time and tell me you can tell it's off side. Make sure you watch the assister's boot until it connects with the ball which starts the through ball to play Ronaldo through, and then move your eyes to check if there is anyone offside. It's not possible.
Linesman are expected to do this in real time, seeing it once, when they can't always keep up with play, and are meant to interpret interference and whether an arm/half a torso is offside or not, all whilst looking in two places at the same time and running up and down a line at differing paces. It's not fair to expect them to get this right all the time. I've ran the line myself and have first hand experience of how hard this is with only 12 year old kids! Imagine Ronaldo pace lol.
I once watched a training video in a room full of coaches, and for a laugh, we were all asked to vote offside or onside on a demo video where you get a point of view of a Linesman on about 5 offsides. Needless to say the results were totally sporadic and mainly just guesses. The aim was to show you how hard it was/is.
Video assistance needs to come in whatever the cost, and I mean even if the cost is stopping play more often.