Thats great and good on ye,but your dogs are being used in an artificially created den,and to me thats not a test,the depth is known,before the dog is entered,...the route in and out is known with no surprises along the way...in my opinion you could never be invited out to hunt in a natural way as your dogs may be (and proper glens usually are) a little too large to manouver and FIT through the tubes to reach the game..this then goes back to the fact they werent bred to be dug to,they were bred as a draw dog,a vermin killer,an "end of dig dog"... by those that knew their dogs...