My dog is a little over a year old. He is a white boxer/pit bull. He loves to play, however if I let him outside without a leash he runs away and thinks it's a game when I try to catch him. He's very quick so no matter how fast I go he is always faster! I cannot figure out how to keep him in the yard or for him to come when I call him!! I'm worried he's going to get hit on the road sometime. Help please!