Measure against recidivism and skipping bail?

Surely we have a baseline that can be used, such as when these systems are not in play?

If skipping bail is the criteria then how do you detect when you incorrectly denied bail?

Doesn't the verdict of the trial related to the bail request have impact upon that? (legitimate question. I don't know if non-guilty parties are more/less likely to skip than guilty parties?)

That's assuming that we can agree that the justice system works impartially to begin with. I don't know of many people (including myself) that could agree with that.

Use a trial period where you grant bail to everyone (non violent offences only). You could run many different algorithms and models, recording all of their predictions. Since you granted everyone bail, you have a clear picture for which predictors accurately denied bail to the skippers.