Hit it harder...goes thru the holes faster.
Ask Bonds about his BA.
Probably increases batting average about 10-20 points, but there's a little bit of a tradeoff there. Some ground balls may get through holes with steroids but not without, but some slow ground balls may get to infielders quickly enough to get outs which might have been infield hits otherwise. Of course there are balls that would otherwise be long outs without steroids that become home runs or extra base hits. But there are also balls that otherwise drop in front of outfielders that with 'roids go far enough for them to catch.
Probably increases batting average about 10-20 points, but there's a little bit of a tradeoff there. Some ground balls may get through holes with steroids but not without, but some slow ground balls may get to infielders quickly enough to get outs which might have been infield hits otherwise. Of course there are balls that would otherwise be long outs without steroids that become home runs or extra base hits. But there are also balls that otherwise drop in front of outfielders that with 'roids go far enough for them to catch.