There are to many variables for me to set a 20 yd max range. Although the majority of the time mine stay inside 25, I don't reel them back in until about 40. Wind and cover play a role in how aggressively a dog works and how comfortable the dog is in its hunt. I think the most important thing to consider is the bond formed between yourself and your dog. It's a joy to watch a dog work, knowing the two of you are working as a team. There is no place for a self hunting dog or over controlling master. Trust the dog, let him work. Pat him on the head when he's doing good, give him a dirty look when he screws up.( Look at his body language, he understands.) When the time comes ( in hot pursuit) when he stops, looks back at you, lets you get back into range and then puts that rooster up the two of you just trailed 150 yds you get it.
I'm not being disagreeable, I just thought some things were left out.