Thanks, Snorky998! Maybe the reason G only weighs around 35 lbs is the Basenji part of her. Can't help it if the rest looks shepherdy.
As for the ball-chasing, 1st, the tennis ball is the thing she loves the most in the world. 2nd, I don't let her have a tennis ball any time but when we're fetching, so it stays really, really special. 3rd, over time she has come to understand that the second ball does not get thrown until she's dropped the first ball at my feet. She is, of course, brilliant, so she gits it, but she's also brilliant, so she tests all the time. She'll drop it a foot away, and look at me. I'll shake my head and she'll bring it closer. But as long as I pay attention and only launch when the first ball is dropped correctly, she knows how it works. If she didn't adore the ball, it wouldn't work. There's got to be something in it for her. Frisbee? Fuhgeddaboudit. But the ball is her obsession. And thank goodness we've worked out this system, b/c I'd never be able to give her the daily exercise she needs without it. She's wound tight before, and sacks out afterward. I love it!
I thought she'd be good at lure coursing, but figured she'd be THAT dog who cuts across the field b/c she's figured out which way the bag is going to go.