The short strokes

I know the phrase "getting down to the short strokes" means time is short or close to the end but does anyone know the derivation of this phrase

It's sexual.

Oops! Now I know why I got those strange looks the last time I used this phrase. Is it/should it only be used in that context?

ROLF! It's from GOLF. You know first you take long strokes and then you putt = little bitty strokes. RRC