Double Bass Which Side of the Bridge Faces Down

The more flat side (the right-angled side in relation to the feet) should be toward the tailpiece, allowing more "angular leverage" to help avoid having the bridge flip toward the fingerboard.

But, lots of people have them the other way, even after being properly setup by highly regarded luthiers.

Maybe the point is that however it is done, a bridge still needs to be constantly maintained to be perpendicular to the table top despite string pressure to lean toward the fingerboard.