Round 1: match 8 with 1, then pair up the rest symmetric to that line.. 1 | 7---|----2 8 6----------3 5----4 Round 2: match 8 with 2, then pair up the rest symmetric to the line.. 1 7 \ 2 \ \^ \ 8^ \ 6 \ 3 \ \ \ \ 5 4 Round X: ... keep rotating around the circle, etc