Speaking from a purely anectdotal point-of-view...

I went through a similar experience at about the same age as your DS. I knew I was identified as GT, as did many other people including mothers of my friends, scout leaders, etc. I felt tremendous pressure to succeed in everything, and when I didn't succeed - I gave up. I think I used success as validation, so, when I couldn't do something, I didn't try because I didn't want to have my self-worth come crashing down.

I think this problem is very age-dependent and personality-dependent. I see similar traits in my DS, who is much like me in his intensity and sensitivity. My DD is much more open to trying something even if she may not excel. It's just a function of their personalities, and I believe these problems get better with maturity and age. I have seen improvements over time with DS, and yes, with myself. Heaven knows I've had many years to improve laugh.

Maybe your DS will grow out of this problem in a few years. Hopefully he can learn to enjoy chess in the meantime, and maybe he doesn't have to be the expert right now.