I think in this challenge you need to hit people with some sort of emotional impact. It's a good pic of a chess set and I get the concept but it just falls short in having that aforementioned impact.
i like the selective focus, if i could have my way id add a little more contrast and maybe move a little bit closer to the king and queem, really just squeeze them in there.
I like this photo a lot, but the depth of field seems a little too narrow. If you could have managed to move the focus forward about 3/4" it probably would have worked out better. (There's some of the front board that's in focus, but the back of the king/queen are OOF.)