I scratched my chin and occasionally picked my nose for a long time while coming up with these. For this year's CNBC Million Dollar Portfolio Challenge, I decided to cluster my stock selections by sector. Since we can create five portfolios with a minimum of four stocks each, I did just that: five portfolios with four stocks each. Going with just four stocks maximizes my chances; any more than that, and I'd be diversifying my portfolios too much. The name of the game here isn't Who's the Best