Once again earlier this season I was shown that there is no foolproof way to tell if a gobble is from a jake or a tom. This past weekend I got on a bird with a full, mature sounding gobble. Ten minutes later it shows up, and its three jakes. So, as said before, I dont really think there is any way to tell with 100% certainty whether it is a jake or not. Certainly, there are times that the jakes do the halfgobble and its clear that its a immature gobbler. But not always.