Sabermetrics indicates are a few ways that HBD deviates dramatically from actual baseball:

1) Pitchers have very little control over batted ball outcomes in real life. in HBD, elite pitchers post low BABIPs year after year.

2) Similarly, hitter BABIP is much more knowable and consistent in HBD than in real life.

3)?Hitters’ splits against righties versus lefties are basically unknowable in real baseball, other than the general splits of righty hitters doing better against lefty pitchers and vice versa, on an aggregate basis. In other words, the whole concept of a lefty-killer, or some player that has pronounced platoon splits as a true-talent, is false. Yet in HBD, splits are perfectly knowable.

also, there doesn’t seem to be a third times through the order penalty for starting pitchers or a reliever familiarity penalty (ie seeing the same reliever multiple times in a series).