True, but in my book there's nothing cheesier than switching balls to meet the shot demands.
Bogey
Okay, but why is changing balls between holes any worse than changing clubs ON EVERY SHOT?
Seems like you, and the USGA, are drawing some pretty arbitrary lines.
K
As Ken makes clear, you may change balls from hole to hole, but not within a hole (with exceptions, at least, for a lost or damaged ball). Several years ago I was playing an interclub match under "lift, clean and place." My opponent took this as license to change balls between the lift and place. He even pointed this out to me as a smart tactical move on his part. I kept my mouth shut.
On the question at hand, I agree with those who've said you've got to factor in everything - ground conditions, slopes, green contours, wind, ball, club selection, how you strike it, luck and so on. Ball flight is only one piece of the puzzle. That being said, I addition to all of the "modern clubs" I carry, I also include in my bag two 1950s steel shafted Power Bilt "Citation" blades - 8 and 6 irons - specifically for "ground game" approaches when the circumstances call for a particularly lower approach (I also find that for me they work better from deep rough than the modern clubs).