Training bay dogs in a pen or wooded pen

I have had two woods pens one 50 acres the one now 300 acres .... dogs just don't seem to be near as catchy in the woods as in the pen ... I have had some that would not catch a pig in the woods but would bug eyed catch in a pen .... if I get one that is catching to much busting bays I clip teeth ..... people use to bring me cowdogs to clip for them cause a stripped ear ain't good through the sale ring on a calf or cow ....most usually back off ......kinda like a cow with bad horns cut her horns she usually quit fight'n so bad .....