Piper Play

I went home after work to see my dog and play with her in the back yard for a while before the sun went down. And realized she would be perfect for my class assignment "play" So i grabbed a ball and started throwing it around the deck. I set the camera to "sport" and multiple shot. The dog wasn't actually the issue in this photo shot, rather the size of my deck, by the time I threw the ball and put the camera back in position she's practically be back with the ball. I took a whole bunch of shots and as frustrating as it was I think I got a few good ones. She's really quick even for the "sport" mode. Other then placing the camera on a tripod, which I thought would be a bad idea because the deck would "shake" as the dog ran around, should I have used a faster shutter speed and larger aperture?

STATS
Shutter : 1/125
Aperture : F3.8
Mode : Sport
Focal L. : 18m
ISO : 800
White B. : Auto
Flash : No
Edits : Cropped the image down, turned up the contrast a few clicks, and the over all color a few clicks richer.