I have spreadsheet that attempts to figure out the net score on a hole in golf, where the number of strokes given is determined by the individual's handicap and the handicap rating for a given hole.

Specifically:
A -Individ handicap = 0 - 27
B -Hole handicap = 1 - 18
C- Gross strokes on that hole = 1 - 9

Need a formula that will cause
0 strokes to be deducted from the gross strokes if A < B
1 stroke to be deducted from the gross strokes if A is > B, and B is less than 19
2 strokes to be deducted from the gross strokes i A is >B, and B > 18

Make sense? What would be the formula to do that? Thanks.