Lonegoose,

The purpose of tapering is to shed the fatigue you have built up from high training volumes/stress without losing too much fitness. As your fatigue sheds, your performance will rise up until the point where fitness also begins to decline at a rate faster than fatigue

In otherwords, during a taper, your true fitness will wane a bit, but fatigue goes away much faster, and your overal performance will improve.

So tapering for a sprint depends on how hard you are training...how many total hours, days per week, what kind of intensity, etc. Most people just need a few days of lighter work before a sprint race, but if your sprint triannng is taking you to your maximum abilities in terms of just completing it, you'll likely need time ot recvoer.  A sprint taper of longer than 7 days shouldn't be needed, and maybe as short as 3 days.

Everyone is different and you'll have to experiment, take notes and tweak for next time.