with my vizsla, I have found that her recall is diabolical unless I have extra special treats on offer. Forget the puppy training treats in jars etc. What she loves is cheese, salami, ham, chicken, etc. I cut it up into really tiny pieces (little fingernail size) so she only gets a tiny taste in order to keep up her interest.
Recall is dead simple - it must mean the beginning of something fun not the end of something.
So if your dog is playing with another dog the reward to come to you must be better than playing with another dog.
So the reward could be a toy a fantastic treat or something the dog loves the best. For one dog I train it is a play with a flower pot!!!!
So when there are no distractions find out what the dog loves only let the dog have this wonderful item when you call the dog. Also never stand still when you call the dog always run in the opposite direction to the dog they usually love to chase a moving object.
Never call the dog if there is no chance that it will not come to you
If the recall is rubbish have the dog on a long lead and train recall with the lead.