I think it is a lot for cricket umpires to decide whether a foot with a boot on it (or some part of the boot) has landed behind a thin white line from their position behind the stumps.
It has caused a lot of angst this cricket season.
In the overall scheme of things, don’t the administrators feel that the “no ball” is a blight on the game, and mostly a waste of time. Different if the full boot lands over the crease line and no part of the boot touches the line.
If the line was slightly wider (2.5 cm), and the rule only applied if no part of the boot ever touched the line during the delivery stride, then I’m sure there would be far fewer “no balls”, and the game would be better for it.
This might encourage the administrators of the game to look at the crease line as being part of the batsmen’s “safe” territory. In other words , if some part of the bat or the batsmen’s body/clothing is on the crease line the batsman is “not out”.
It would seem to me to be a better interpretation, given the batsmen can never separate in from out as he dives/stretches for the line.