I think you are confused.
I don't think any one here was claiming to have found the new foxing breed.
The question was, can a whippet kill a fox single handed. The answer was, yes, some can. Maybe not regularly, and maybe not several a night. But anyone who got a whippet purposefully to hunt fox, is a fool.
But to say that a whippet trying to kill a fox is like hitting a rhino with a stick is retarded. Yes you get some tough foxes, but its a fecking fox, not a timber wolf. A dog does not need to be the size of a donkey and weigh the same as a mini to kill one, they ain't THAT big.