“(That's not strictly true as you can cross an out-of-bounds line so long as your ball finishes in-bounds).”
Well, as Scott notes, I do have an interesting story about this and someplace I still have all the “official documents” (I think) pertaining to this issue. I was in a club tournament IRL. The hole I was playing was a dog leg left, about 70% - 75% bend. My ball was positioned on the left side of the fairway just short of the start of the dogleg. At the start of the left hand side of the fairway where the dog leg begins its bend to the left, was a marker, about 10’ high with a sign attached stating “stay right of this pole”. I hit my approach to the green, 4 iron, just cutting to the left of the fairway and landed just feet from the pin. Yes I was ecstatic, but not for long. I was challenged on the flight path of my shot. It was contended that my ball, although it traveled straight, due to the angle of the shot in all probability traveled left of the post (no one actually saw the entire shot except for me; it was one of these you could not have landed on the green where you did without traveling to the left of the post). My response was I can’t say with 100% certainty that 100% of the ball traveled completely to the right of the post, at worst it travelled over the post, but regardless, the shot is in bounds as you can see. No sir, I was told it was out of bonds. My comment was you are penalizing the flight path of the ball, you can’t do that. A ball can travel OB, but if it comes back in bounds during its flight and lands in bounds it is in fact in bounds. We finished the round and went to the club house and we presented the matter to the guy running the tournament. His ruling, if at any time during its flight the ball travels out of bounds it is automatically out of bounds even if it lands in bounds. I appealed to our club’s rules committee. They reviewed the matter and ruled the same, out of bounds. So I decided to write to the USGA and much to my surprise they agreed to rule on the matter. I eventually received a reply that included their official ruling. In short, they ruled that they could not intercede in the matter as under the rules of golf the determination of golf course boundaries is established by local rule. So, if your club elects to penalize the flight of the ball, it is permissible under the rules of golf. They did admit that in my particular case the ruling of out of bounds did seem unfair, but that is how it works. Still wouldn’t give up. I went back to our local rules committee and lodged an official protest. In support of my protest I submitted an example every club member knew - our club president’s tee shot on the exact same hole. From the tee, the first half of the fairway is 100% straight, with a small creek and wooded area to the left of the fairway. The creek was the boundary for that part of the hole. The creek was obviously a lateral water hazard, but anything to the left of the creek was OB. Our club President had a wicked, wicked slice; it was legendary. In order to put his ball in the fairway on that hole, he needed to aim to the extreme left and his ball would therefore travel over the wooded area, over the creek, and into the opposite fairway before it would begin its curve back into the fairway of the hole under discussion. I contended that hitting his tee shot in that fashion meant his tee shot was definitely OB as the rule for that hole stated if any part of the ball’s flight crossed the boundary marker, it was determined to be OB. The committee, to whom I had submitted my USGA material beforehand, ruled as follows. The assignment of boundaries and the determination of OB areas is, as the USGA states, the responsibility of the club and is controlled by local rules. In this case, the tee shot in question does transverse into an area that is determined to be OB. However that is a local rule and the committee has, under its right to issue local rules, determined that in order for the player in question (club president) to successfully play golf on that particular hole consideration had to be given to his peculiar driving technique and had therefore previously issued a local rule that exempted him from the OB rule for that hole. Ergo, he was permitted to fly his ball through an out of bounds area without penalty where I was not. All “legal” under the USGA’s interpretation. Should mention that as part of the reply I did receive from them they did seem to indicate that they were not in favor of local rules in general, but given that not every situation arising in a game of golf can be codified/addressed in a rule book, local rule authority needs to exist.
In the WGT game I have flashbacks about this incident every time I play RSA #16, I believe it is, the hole with the fence and road to the right. Playing in a right to left crosswind, I have to aim to the right to compensate for the wind, meaning I’m hitting outside the established boundary of that hole; I can see it happen and I keep waiting for buzzers, sirens, bells and whistles to sound off declaring the ball OB. But it never happens.