There is a difference between Pros and the first time dog handler,you can't compare the two.
When you see the dogs that "wash out"with the so called Pros then I wonder about their training methods too.

@Dakota Creek,Personally,I don' t start heel training with a leash either.it is off leash and only when the pup understands where the right position is do I attach a leash.

Just my opinion

Rainer