Yesterday, one of The Waiver Wire's readers asked the following question about designing a new scoring format: "If one were to start/join a fantasy league that only used one or two categories for hitters and pitchers which categories would you choose?"
The truth is, I would probably choose something funky that I think I could forecast better than others - for example, home runs allowed for pitchers. I assume that's not really what Mike was looking for though. I'd guess he's looking for categories that would have some relation to the actual 'quality' of player, and would produce player values that have some similarity to more traditional leagues.
With that as the goal, I think you'd generally need two categories to create a balanced game. For hitters, I'd probably go with batting average and home runs, although I suppose that replacing batting average with steals would work pretty well also.
For pitchers I'd use ERA and either wins or strikeouts. That would require players to go for 'quantity' as well as 'quality' and would eliminate most of the potential gimmick strategies.
Mike went on to suggest OPS as a potential single category for hitters. That would work fine, as long as there's a requirement for players to reach some minimum number of at bats. Likewise, ERA could be used for pitchers, as long as there's an innings pitched minimum.