I'd add to really watch your horizons too. The first is overexposed which can happen easily in harsh overhead sun. With no exif in your images, I can't really comment on settings that might have changed it. In tough light like that, I think shooting manual is your best bet. Anything auto will get exposures all over the place as the camera tries to figure out how to meter. Expose for the faces and then tweak if you need to. The second is a totally different issue in that you have the same tough lighting but made thigns even tougher by backlighting the shot. In conditions such as those, I'd highly recommend keeping the sun at your back until you've really sorted out your exposures and have plenty of keepers already from the match. Keep at it, like anything in photography, it takes some time to get it all right.