Our boys have very different techniques when it comes to playing fetch.
Trooper likes to catch the ball, then endlessly play 'keep away.' He enjoys been chased and playing tug-of-war with the ball. He also ruthlessly pounces on and steals tennis balls (or squeaky toys) to prevent others from playing with them, especially if the tennis balls are new and clean. He is also partial to new, loud squeakers.
Jake, on the other hand, is a fetching machine. You can throw a tennis ball, he will run after it, pick it up, and drop it right at your feet. Repeat. If you do not throw the ball again, he will nudge it with his nose to make sure you see it. Once you begin throwing tennis balls, he will run after them, and bring them back for hours. Literally. I think he would collapse from exhaustion before he willingly stopped playing fetch. His one point of pickiness: he is a purist. It must be a tennis ball. No squeak toys, no rubber balls. Good, old fashioned, neon-yellow tennis balls...dirty or clean.
This is how we spend a great deal of our time, even on cold days.