OK, I'll bite: Very few in comparison to overall rounds. In 30 seconds of thought, I count 17. And for the record, MHM, I walked all and didn't use a yardage device. I admit I bought a yardage book (stroke saver) at Aberdeen but found it relatively useless in the wind (except as a souvenir from a great track). Personally, I'd say that playing a links should be on every golfer's bucket list. However that is a fairly expensive prospect for a lot golfers on this planet who love the game that they know and can afford.