bluegreyhound is right. For pure strength with little mass do singles reps for very heavy weights 90+% of your 1RM with plenty of rest in between. There is an interesting book called "underground secrets of sprinting" or something along those lines by a bloke named Barry Ross.

He talks about never doing more than 10 total reps per workout, using only deadlifts with 5 minutes rst between sets. As soon as you finish the deadlift set though you immediate do a set of 5-8 depth jumps. The idea is that with such low volumes you can train more frequently and never add much muscle size but you can get really strong per pound of bodyweight. The depth jumps ar supposed to wok onthe RFD component.

I did a lot of deadlifiting last year using mostly very heavy singles and there was a definite correlation between getting strong and increasing my vert. To a point. When I reached 440 pounds my vertical stop improving even though I managed to add another 30 pounds to my DL max. from 350 to 440 I noticed great gains in my jump.

Regards

Jaydub