This is our 2nd pair for this early 2020 baseball season. My son is 12 yo and wears a men's 10 shoe; purchased a large. Our first pair was a medium donated by the coach and purchased locally (same brand). Both socks have holes in them after one wear. One pair has a hole in the knee from sliding, however there are holes at the top of the ankle on both which is odd.With that said, there is a definite seam on the back, but that would be tolerable without the holes.