Let's start near the bottom of your scores. We can find good ways to improve these. First, I see by your comment that this was a set-up shot. Good. BUT, since you set it up, you should also set up your background. Ask yourself, does that part of the background add or distract from the subject? I'd start by asking the bald-headed gentleman to remove himself from the pic. He only takes out eye away from the action. The rest of the BG isn't bad, although I'd probably have moved the net and pole too.
I know from the scores thread that you were disappointed in your score. I contributed to that (3), so I should say why.
This is a fine family photo and one that friends and relatives who know your subject will enjoy. For the rest of us, it is a different story - we look at this in the context of a Free Study; beyond the timing that you have nailed - there is little else to interest a viewer. Sure it is sharp but with the large DOF it would be difficult to miss that. I can only speak for me but when I look at images on DPC, I hope to see more than a well executed image, I'm looking for such things as story and narrative, a bit of mystery, things left unsaid, un-shown... ambiguity. For the images that don't have that, fantastic technicals in difficult lighting or with high speed subjects can carry the day. Besides pointing the camera and timing the shot, there is little of you and your artistry in this picture, it tells me little about the sort of photographer you are or what interests you visually. Have a look at the comments I gave out in this Free Study - I may not be typical of the DPC voting pattern but it least it will give you a bit more information as to what pushes my buttons and why this one didn't.
A fun shot, but it does come off as a snapshot. One thing I found recently when I was photographing the "splash day" at a YMCA, was that by using my 250mm lens and a fairly wide aperture, the busy background was nicely blurred and it improved the pics tremendously. Either that, or getting really close to the subject did the trick. Pool shots certainly have their own issues.