When I first found out what hybrid in hybrid bowling balls actually mean.

According to Darren Tang on his YT channel, hybrid doesn't mean the cover is mixed with a blend of hybrid/solid coverstock (meaning the whole coverstock is at least consistent).

Apparently, it means parts of the ball are solid and other parts are hybrid, usually denoted by the different colors. Example: Yellow colored part of the ball is solid and blue part is hybrid

I'm only taking Darren Tang's word for it but I figure it must be true.