I think you would 1st have to establish some reasonable proxy for sheet nos.(some combination of the old drf speed & variant nos?), decide on your definition of a bounce, have access to pps for at least 5 races prior to the classic days you indicate you do have, and know the no. of races as a 2yo & 3yo. In other words, I'm not sure if there's any way to do what you want to do unless you're have access to drf databases & are able to enlist some of the computer wizards on this Bd to help you. Sorry I couldn't come up with a better answer.