1 2 3 4 6 7 5 9 11 8 10 12 11
There is an easy if not a little complex way. you can generate a near analysis on each point to find the point that is closest to it. start off by drawing lines between a point and its closest neighbor
9 would go to 11
12 to 11
10 to 12 and in this case 8 might go to 9
3 and 4 would partner up but instead go to 6