It's a strange one Marshman and surely one that nobody really knows the answer to.
This little tale has reminded me of something my original 'mentor' once said to me. I had a first season terrier that really started well, he was going great and I ended up going on invites with lads to big old earths with a reputation about them, such was my belief in the young dog, and he always got the result. Anyway I remember being out one day digging and we were talking about an earth that goes to 12/13 foot deep, and this 'older lad' said I'd be able to dig it with my young dog, I said he must be jok