The colour is a bit flat on this one, but the composition is wonderful. I think the voters were looking for lots of action though. Maybe if you'd caught him in the middle of a swing? All the best to your son, good luck in future tournies!
This is a good shot but would really benefit from just a little post-processing. Increasing the saturation and density would really have made this a great shot
This is well composed and meets the challenge theme quite well. The side lighting is giving you some trouble it seems. The contrast is high enough, but there appears to be a little flare that is fogging the image up some. At first glance I'd say boost the contrast (hold down the brightness), which would help - but then you're going to blow out the highlights I think. Try boosting the black some instead and pull down the highlights? All JMO of course. :D Good luck in the challenge.