In the "field of 65" style tournament bracket, there were two 16-seeds (presumably the weakest teams) that had a play-in game in order to play the overall #1 seed. When they expanded to 68, it's now 4 play-in games between 16-16 seeds, 13-13 seeds, 11-11 seeds and 16-16 seeds. Why didn't they just do it between all 16 seeds? Was there specific reasoning? Is it the same seeds in each region every year or is there a mechanism for selecting which teams will play in Round 1.
(I know it can be debated that playing in such a game can be a good warm-up for lower seeds, but I don't think that was the official reason.)