There is no rule in the books about this, hasn't been in the 5 years I have really been studding the rules. That said, 3 years ago we had a guy do this with almost every ball he threw. He crossed my lane ( 2 lanes down ) one time, last time. I was already half way ( give or take ) down the approach. He ran into me, he wished he hadn't because I'm old but stocky so needless to say, he fell down, slid a bit. He looked up as I asked him if he was OK. He hadn't time to answer before I said, if he crossed my lane again I will not stop or slow down, he's in MY lane.
Needless to say, our league hasn't had a problem since. I will always give the lane next to me courtesy, allowing anyone who wants to do that the room to do so but 2 or more lanes down ? Enter at your own risk.
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az guy aka: R & L Bowlers Pro
rlbowlerspro@cox.net