Old Skier
Tour Winner
This is a case for the terms of a comp to state that ALL cards are to be returned as a reminder to competitors that cards must be returned as they do have an effect on the CSS.Surprised how much this isn't known.
Had a guy in my office who played massively under his handicap in a comp for all but one hole that he ended up putting NR on. Because of this he simply didn't return the card as he no longer thought his card was valid. Problem is, he he would of actually been entitled to a cut. Buy not returning a card it's open to abuse for people to increase their handicap... likewise though if it was changed so you didn't get 0.1 back you'd have the opposite problem with people at a potentially lower handicap than they should.