Very good exposure and focus seems to be spot on Agree with Carl, #3,6 & 9 could be cropped tighter. Few of them are past peak action. It's a timing thing but should improve the more you shoot.
Excellent series. All nice and razor sharp. I especially like #7 with the two running directly at you both in fulll stride and the background nicely blurred. Why does the aperture change from f 2.8 to f 3.2 even to f5? The iso changes, too, even reaching iso 1000. Are you shooting in Program mode auto iso? I always shot sports in manual with the aperture as open as possible to keep iso down and shutter speed up. The shots turned out fine so just nitpicking.
Agree with Carl, #3,6 & 9 could be cropped tighter. Few of them are past peak action. It's a timing thing but should improve the more you shoot. 