Opening on track genetic?

These are just my opinions & do not mean much but I have had silent curs & Plotts for a long time. I believe it is a 100% genetic if a dog opens or is silent. I have run silent curs with my plotts for years & it has never made them open. There are some lines of hounds that might be silent but that is the exception to the rule. It is a trait that can be bred for. Now I do think open mouth dogs do seem to be a more dominant trait then silent, for instant when you breed a open mouth dog to a silent dog, it seems like they are more open then silent. I have seen 2 plotts(one I owned & 1 a friend owned) that came out of open mouth parents & for some reason these dogs ran silent. You would only hear them when bayed.