In the ratings book there is a catagory called BP. A better gets w thru 8 against lefties and righties. I always thought 8 was great but now not so sure if it turns a HR into a fly 0ut.
Look closer and you will see that some of those 8 BP home runs, represented on the cards with a # fall on fly ball readings turning an out in to a possible HR.
Basically as Scumby said to maximize your 8 ballpark home runs you need a max HR ballpark with a 1-20 rating.
Flip side if you have chosen a pitcher park with low ballpark HR ratings you want to minimize the number of high BPHR players since you lose some of their value. So one might argue looking for good players with low ballpark HR when in a pitcher park.
You can also use the information on which # rolls potentially remove HRs and which potentially add HRs to calculate which players benefit or are restricted the most from a bomber park verses a pitcher park.