Neil Robertson has called for a revamp of the snooker rules after Jamie Clarke and Anthony McGill became embroiled in a heated conversation during their World Championship second-round clash at the Crucible on Saturday.
Former winner Robertson, who edged into the last eight after completing a 13-9 win over Barry Hawkins, said he sympathised with both players after McGill accused Clarke of deliberately standing in his eyeline as he prepared to play a shot.
The pair had to be separated by referee Jan Verhaas and McGill followed Clarke out of the arena at the end of the frame, before returning to reel off five frames in a row to reduce the deficit to 8-7 ahead of Sunday night's concluding session.
Robertson said: "There needs to be a flat rule where if someone’s playing a shot you sit in the chair, and probably more referees need to be a bit sterner with how they apply that rule.
"If you’re playing a shot and your peripheral vision picks up a player moving as you play the shot, if your vision goes from the object ball to what they’re doing, you can miss the shot by several inches."
While Robertson stressed he did not believe Clarke had deliberately sought to gain an advantage, he said it was an issue which needs to be addressed as it occurs too frequently in the sport.
"Some of the other guys do look for an advantage," Robertson added.
"I’m certainly not going to say that was the case (on Saturday) because the Crucible, especially when you’re not experienced here, is so tight for space.
"It goes on a lot on the outside tables. There are a lot of players who fiddle around with their towel in your shot or they get up out of their chair to see if a ball’s on when you’re about to play your shot.
"For me, I think the (other) player should always be in his chair."