Very nice idea - only comment is the judoka group,could also be for points awarded by judges.

Mister Tom I'll give you 8 out of 10 for your observation. Cheers.

I find it confusing when there is lots of similarities. When I see that I don't have a clue where to start. Never heard of: Judoka, Three day eventer, National hunt jockey, Skeet shooter and Hunter. So I never would have got any.

Think!!! The fact that you didn't know what these things are is part of the process, look them up. As it happens I didn't know what a Judoka was called before I read it although I knew what they did. All of the 16 sportsmen (women) with the one exception would be known by the majority of sport loving people... I will have a go at setting a puzzle that might appeal to your age group. The point about a lot of similarities being confusing is correct. It's meant to be. You as the solver have to decide what differentiates the subjects into 4 groups. It's a themed puzzle... Hope this helps.