Puppy Charlie catching treats
You take a small treat in hand and, holding it shoulder-high so Charlie can see it, swing back once... twice... On the count of two, point it towards his face and let go. Occasionally it may bounce off a tooth, but more often than not, the treat will disappear into Charlie's gaping mouth, almost like it was sucked in by a gravitational force.
Adult Charlie catching treats.
The mailman also plays Treat Catch with Charlie almost every day. Since the game ends when he misses, Charlie is very very focused. He's up to 12 consecutive catches and it's only a matter of time until he hits 13.