It's a bad name for a simple concept. There are several ways of thinking aout it.

A pass must go backwards from the passer to the catcher [irelative to the players[/i (who are running forwards), not relative to the pitch.

Think about looking from above down on the play, but ignore the pitch, just look at the players. If the angle from the passer to the catcher is backwards, the pass is OK.

If the passer is 2 metres in front of the catcher both when the ball is passed and when it is caught, and the players are running forward fast enough, then the ball may have gone forward relative to the pitch, but this wouldn't be a forward pass because the ball always went backwards relative to the players.

It's got nothing whatsoever to do with 'momentum' though!

If it's really obvious then surely there's no reason for the video ref, as the ref/touchjudge should just give it.

A lot of tries are scored from within 10 metres and the mojority of passes to set up close range tries are short and flat.

Momentum is mass multiplied by direction. It obviously doesn't have anything to do with the mass of the ball (or players), only the direction. Therefore, the "direction rule" would have been a better name. That's all I was saying.

The problem with including it in video decisions is that the camera would have to be in exactly the right position to be able to make a correct decision, which is virtually impossible, and in fact from different angles passes can look forward or backward. I guess that's why the RFL decided that the VR could not make decisions on forward passes, which is corrcet IMO.

Correct, but the difficulty would be proving that the pass was forward, which you could only do if the camera was in the right position.

If the camera is not exactly level with the players, then the direction is difficult to judge, particluarly when the pass is rising or falling in height, because that can make it look like the forward/backward angle is different from what it actually is.

Should have been at Wire match today to see how refs (Thaler) can't handle forward pass rule (and knock ons) multiple times......plenty of em from Hull and no callforthcoming; we do one (and score a try) and get pulled up.....

But better team on the day; no excuses ...

The first part of your post certainly sounded like exactly that