The lack of data regarding custody determinations AFTER a full completed trial, is no accident.
If you look, you will find that virtually no public data on custody grants made to the fathers vs mothers exist.
It is a trivial thing for courts to keep track of this very fundamental data. The reason it is not kept and otherwise impossible to find, is that it is the smoking gun proof of bias and discrimination against fathers in family court.
Overall, national statistics show that mothers get sole custody ~93% of the time, that alone shows something askew, but the gold standard of bias is the ratio of custody awards after trial.