I have historical data somewhere. But it really vaires from team to team actually.
But I think the home fave will win by one run roughly 16 or 18% of the time, a home dog will win by one run about 16 or 18%. One is 16 one is 18 I remember that.
Road faves win by exactly one run about 11 or 12% of the time, and road dogs will win by one run about the same 10-12%, can't remember now.
But road teams are around 11% Median/average winning by one run, home teams are around 17% Median/average. So about 5-7% I would say differential.
I have them all broken down somewhere, if you want specifics I might be able to pull some.