A few more things. . . If you feel like COME is a word Max already sees as negative or optional, you can change to a new word and then carefully build the recall with it: "Front" is good if you'd eventually like him to come and sit in front of you when called, but any word will work if you use it consistenly.
Sometimes, randomly run away from Max in a playful way when he is looking at you; whne he chases, give the Max COME command just before he gets to you. Then, treat and praise.
If you can get someone Max likes to help you, play a bunch of fun recall games with a hide N seek theme.
Have someone hold Max's collar while you run and hide with an amazing treat. Call him from your hiding place and give him a HUGE party/jackpot of praise and treats when he finds you. Get in the habit of hiding from him when his attention wanders, then call and again throw him a Max_Is -Awesome party. (Adding the search element gives them the idea/association that coming is fun and channels that same element that makes a rabbit hunt fun.)
Always make it nice for Max when he comes, and don't take it for granted. Even with my almost 7 year old, I make sure I say "Nice to see you, Puppy" in a happy tone. Take care they never associate coming back with being leashed; call ten times more for fun than for serious reasons. There is nothing worse than when people(not you!) call COME to their dogs and then get frustrated and either start pleading or just forget it
Post office is another excellent recall game. Just have two three, or four people take turns saying Max! COOOOOOMMMMMMEEEEEE! When he gets to each person, he sits in front of them and receives a great treat. Then, someone new calls him. It's like Monkey In The Middle with a twist.
Sometimes, Max will make a beeline for you of his own free will. He wants to be petted or you have a ball. Take advantage of when he's already en route and teach him the word association: MAX, COME- Good COME." "Excellent COME, Max. Dogs can learn backwards as well as forwards, lol.
One school of thought says never to use the actual word "come" unless you're 1000 percent sure you're going to get one, and I agree with that. If you're only 50/50% if he'll come when you call, use something else like "pup, pup, pupeeee" in an inviting tone. My golden Raleigh grew up at a summer camp where something more fun than me was always happening, and no treat was more tempting than 480 dog-loving kids and staff swimming in the lake or playing soccer. I had to make an ironclad rule for myself not to call him futiley, when it was just unlikely that he'd muster the self-discipline to come. I'd ask someone to snag his collar and go get him in a friendly way. It is too easy to untrain "come" in a puppy by saying the word and then having it not happen.
A few recall words/phrases other than "come" are useful too in keeping "come" a magic word that is always obeyed. I have about 98 % faith that my dogs will recall under any circumstance- even a deer. BUT, I use "ALL DOGS" to call my whole group at once and "Be With Your Family(random, I know) to signify staying close underfoot but not on a leash if, say, a hiker is coming the opposite way on a trail or tourist are sitting on a picnic blanket at the beach and we have to pass by. I want to keep "COME" a special word with only one meaning. Too many people use come for "in the ballpark of me". Another phrase crazy Raleigh had to learn was "ALL THE WAY" for come right to me. He liked the idea of the ballpark come, but learned it didnt fly bc he had to come all the way every time. The last word I sometimes use instead of "come" is "FRONT". That is all business(fun in a different way) and tells the dog he is working and must come to a very precise sit right in front of me where an imaginary belt buckle would be, and that other commands will follow.
Another good oldie-but -goody is to turn a little away from the dog while calling. Humans accidently put social pressure on a dog by taking a step forward to meet him, though with the best of intentions. Even staring to intently can put off a shy dog. Scootching down and opening your arms wide is great for some dogs, but intimidating to others. Your body langauge can really help or hurt the process. Now that he's a middle aged guy, I can recall Finn by dropping to one knee and opening my arms- it's cute. However, my past dog Cady would stop ten feet from that. She'd come all the way if I took a step back.
Lastly, and Tippykayak has a great post about this somewhere lost in the past threads, imo there is a time for a swift decisive moment that is more old school monks than positive training. Sometimes a "teenage" pup might stop, look at you, and ignore you. If you are sure the pup knows what you want and you can get to him, be an avenging angel for theater's sake. This takes a ton of good timing etc, but is a great learning experience if it is done wisely and well once in a lifetime. Tally and Tango never needed it, but Acadia did once stop, gaze at me, and then turn her back and trot away. I sprinted as quietly as I could, and she was shocked to find herself getting a stern NO! Who knew humans could run so fast? It's the element of surprise that works here, and creating a little belief in the pup that you actually can catch him/her if you choose to. (Ha!). Once you call out "Max, Come", you are locked in and you have to go get him. This is controversial advice, and I don't really adovcate it philosphically, but when it is just right, it is key.
