Watford (a) post-match

[Dribble]

The Jesus call is as tight as a nun's knickers. With the benefit of replay you can see he was just off but it most certainly was a difficult call.

Don't you just love having a striker called Jesus? :-)

Not only can he walk on water, & then turn it into wine, he can also be offside & onside at the same time! Lol

 

[Dribble]

Im always skeptical about tight offside calls that are 'proved' by TV replays. This is why.

I once attended a football workshop. There was a guy there with a speed gun who told you how fast the ball was travelling after it left your foot. I got chatting to him and he said the hardest he had ever seen a ball being hit was clocked at 67mph. He also said that if you roll the ball with the studs at walking pace, that is 3mph. From those metrics, you can deduce that a fairly well hit pass will probably start out travelling at, say, 30mph. Simple arithmetic tells you that 30miles per hour is the equivalent of 14.6 yards a second, or 21 inches every 25th of a second.

I use 25ths of a second, because when slow motion TV rolls on 'frame by frame' it is usually travelling at a speed of 25 frames a second. Which means that between one frame and the next, a ball travelling at 30mph will have travelled the best part of two feet. But in the same time, a player running at 15mph will have travelled the best part of a foot. So in one frame a player will be level, but three frames - three 25ths of a second - later he will be a yard offside, or even two yards offside if the defender has stepped up as the pass was played.

This is important, because many TV replays seeking to 'prove' a player is offside will freeze the footage a frame after the ball has left the attacking player's foot - they did this for instance on MOTD when showing Jesus' goal on Saturday; the 'freeze' moment came not when Aguero played the through ball but a frame or two after it had left his boot. Had the freeze come at the point at which Aguero was actually playing the ball - i.e. his foot was in contact with the ball in the act of playing the pass through to Jesus - I very much doubt TV would have 'proved' that jesus was offside. The wording of the law is that you have to be offside when the ball is played - not immediately afterwards.

Of course in real time, it is virtually impossible to be completely accurate about what are literally split second calls seen once, in real time, with the naked eye. We couldn't have complained if Jesus' goal had been ruled out on Saturday, just as the two offside goals against Liverpool were 'proved' to have been correct calls.

But when we are told that TV replays 'proved' a goal was offside, it always crosses my mind that the proof is actually no better than the technician who is deciding when exactly to freeze the frame.

Never looked at it like that before. I always preferred when the rule was changed to 'There had to be fresh air between the attacker & defender for it to be called offside'.

Nowadays, with a player being in an offside position if the ball is played by a team-mate, they are nearer to the opposition's goal line than both the ball and the second last opponent, is just too confusing as angles and movement by other players can skew the perception of what is offside & what isn't.

Don't ask me what the alternative is though. I think FIFA love the controversy it creates, as it keeps contentious talking points to a maximum.

 

[waspish]

Im always skeptical about tight offside calls that are 'proved' by TV replays. This is why.

I once attended a football workshop. There was a guy there with a speed gun who told you how fast the ball was travelling after it left your foot. I got chatting to him and he said the hardest he had ever seen a ball being hit was clocked at 67mph. He also said that if you roll the ball with the studs at walking pace, that is 3mph. From those metrics, you can deduce that a fairly well hit pass will probably start out travelling at, say, 30mph. Simple arithmetic tells you that 30miles per hour is the equivalent of 14.6 yards a second, or 21 inches every 25th of a second.

I use 25ths of a second, because when slow motion TV rolls on 'frame by frame' it is usually travelling at a speed of 25 frames a second. Which means that between one frame and the next, a ball travelling at 30mph will have travelled the best part of two feet. But in the same time, a player running at 15mph will have travelled the best part of a foot. So in one frame a player will be level, but three frames - three 25ths of a second - later he will be a yard offside, or even two yards offside if the defender has stepped up as the pass was played.

This is important, because many TV replays seeking to 'prove' a player is offside will freeze the footage a frame after the ball has left the attacking player's foot - they did this for instance on MOTD when showing Jesus' goal on Saturday; the 'freeze' moment came not when Aguero played the through ball but a frame or two after it had left his boot. Had the freeze come at the point at which Aguero was actually playing the ball - i.e. his foot was in contact with the ball in the act of playing the pass through to Jesus - I very much doubt TV would have 'proved' that jesus was offside. The wording of the law is that you have to be offside when the ball is played - not immediately afterwards.

Of course in real time, it is virtually impossible to be completely accurate about what are literally split second calls seen once, in real time, with the naked eye. We couldn't have complained if Jesus' goal had been ruled out on Saturday, just as the two offside goals against Liverpool were 'proved' to have been correct calls.

But when we are told that TV replays 'proved' a goal was offside, it always crosses my mind that the proof is actually no better than the technician who is deciding when exactly to freeze the frame.

Yep and why I called those supposed offsides on side after I watched it again and froze it at the right time.

 

[Chris in London]

Yep and why I called those supposed offsides on side after I watched it again and froze it at the right time.

Didn't take a piccie did you by any chance?

If you did, you know the rules!

 

[Rolee]

Im always skeptical about tight offside calls that are 'proved' by TV replays. This is why.

I once attended a football workshop. There was a guy there with a speed gun who told you how fast the ball was travelling after it left your foot. I got chatting to him and he said the hardest he had ever seen a ball being hit was clocked at 67mph. He also said that if you roll the ball with the studs at walking pace, that is 3mph. From those metrics, you can deduce that a fairly well hit pass will probably start out travelling at, say, 30mph. Simple arithmetic tells you that 30miles per hour is the equivalent of 14.6 yards a second, or 21 inches every 25th of a second.

I use 25ths of a second, because when slow motion TV rolls on 'frame by frame' it is usually travelling at a speed of 25 frames a second. Which means that between one frame and the next, a ball travelling at 30mph will have travelled the best part of two feet. But in the same time, a player running at 15mph will have travelled the best part of a foot. So in one frame a player will be level, but three frames - three 25ths of a second - later he will be a yard offside, or even two yards offside if the defender has stepped up as the pass was played.

This is important, because many TV replays seeking to 'prove' a player is offside will freeze the footage a frame after the ball has left the attacking player's foot - they did this for instance on MOTD when showing Jesus' goal on Saturday; the 'freeze' moment came not when Aguero played the through ball but a frame or two after it had left his boot. Had the freeze come at the point at which Aguero was actually playing the ball - i.e. his foot was in contact with the ball in the act of playing the pass through to Jesus - I very much doubt TV would have 'proved' that jesus was offside. The wording of the law is that you have to be offside when the ball is played - not immediately afterwards.

Of course in real time, it is virtually impossible to be completely accurate about what are literally split second calls seen once, in real time, with the naked eye. We couldn't have complained if Jesus' goal had been ruled out on Saturday, just as the two offside goals against Liverpool were 'proved' to have been correct calls.

But when we are told that TV replays 'proved' a goal was offside, it always crosses my mind that the proof is actually no better than the technician who is deciding when exactly to freeze the frame.

This crossed my mind in light of the possible introduction of video replays. I guess if they are brought in across the board then it would have to be clearly defined.

 

[Chris in London]

This crossed my mind in light of the possible introduction of video replays. I guess if they are brought in across the board then it would have to be clearly defined.

You get a similar issue in cricket where TV footage is used to try to show whether a ball has grounded before a catch is taken. Rolling the footage on frame by frame does not always give the clearest picture of whether a catch was taken cleanly.

I suppose VAR might work well if, like most umpire reviews or decision in rugby, the question is 'is there evidence to justify overturning the on-field decision', but if VAR involves simply passing the buck, it might be more difficult.

 

[SilverFox2]

You get a similar issue in cricket where TV footage is used to try to show whether a ball has grounded before a catch is taken. Rolling the footage on frame by frame does not always give the clearest picture of whether a catch was taken cleanly.

I suppose VAR might work well if, like most umpire reviews or decision in rugby, the question is 'is there evidence to justify overturning the on-field decision', but if VAR involves simply passing the buck, it might be more difficult.

Hi Chris, your points are valid well spotted.

Presumably in the UK our 50 Hz frequency is ideal to allow interlaced transmission (to save bandwidth) where odd and even frames are transmitted alternately and then your TV or STB de interlaces them via algorithms to give us the complete progressive frame we need to allow viewing at half frequency ie 25fps close to the films 24 fps..

USA electricity is at 60 Hz so it gets 30 fps from the same processing so is that a little more accurate or do they simply use our original cameras and change frequencyfor USA viewing ?

I suppose unless the replays are taken from video done at slow motion speeds ie more fps the replays will have the degree of interpretation you lucidly indicate.

 

[Chris in London]

Hi Chris, your points are valid well spotted.

Presumably in the UK our 50 Hz frequency is ideal to allow interlaced transmission (to save bandwidth) where odd and even frames are transmitted alternately and then your TV or STB de interlaces them via algorithms to give us the complete progressive frame we need to allow viewing at half frequency ie 25fps close to the films 24 fps..

USA electricity is at 60 Hz so it gets 30 fps from the same processing so is that a little more accurate or do they simply use our original cameras and change frequencyfor USA viewing ?

I suppose unless the replays are taken from video done at slow motion speeds ie more fps the replays will have the degree of interpretation you lucidly indicate.

The answer to much of this is 'I don't know' but I do know that the footage is provided by Sky/BT and then licensed for broadcasting overseas.

 

[bluestevei]

He's a right back. I thought he could do both too, but against Brighton he kept having to check his run to cut back in onto his right foot which slowed our attacks. Mendy starting the next few games showed exactly what we were missing and the limitations Danilo had playing left back.

thanks

 

[SilverFox2]

The answer to much of this is 'I don't know' but I do know that the footage is provided by Sky/BT and then licensed for broadcasting overseas.

Thanks Chris,

When I watch athletics the finish line of say the 100 metres is in slow motion with its many fps value to get exact timing to coincide with the actual frame when the athlete crosses the line.
Similar situation with horse racing because it allows accuracy for results.

I suppose under normal circumstances there is no harm or potential error in using normal footage for offside decision checks but for very close decisions it cannot be definitive because of the limitations you describe.
In fact the situation becomes just as if it was in real time with the linesmans eye which sees things at about 24 fps then the brain processing the in between frames as a continuous event which will vary from person to person using anticipation skills.

For the TV channel to claim accuracy with a single frame from a non slow motion video is wrong so perhaps they should show the immediate frame either side of the so called accurate one to explain their conclusion and maybe then some will agree and others will not if it is that close.