The Modified DH: No Way.

I just read a proposal regarding the impending destruction of the National and American Leagues, and the implication that destruction has on the current major difference between the rules in the two leagues, the designated hitter. (Yes, destruction is the right word: two sets of teams of odd order who will be encountering each other every day are not separate leagues, but separate divisions.) It feels problematic to maintain the two separate DH rules if interleague play becomes an everyday matter, since any American League full-time DH on the order of David Ortiz would have to sit out routinely but any National League team would be unable to stock a full-time DH and would thus suffer a disadvantage in American League parks. It seems likely that the result will be the adoption of the DH across the entirety of Major League baseball, and the abolition of pitchers hitting in North America.

Instead, this proposal would adopt a uniform DH rule across the two leagues, but with the DH replacing one of the eight players other than the pitcher. The only advantages listed of this system compared to a uniform standard DH system are that pitchers would see better defense behind them, the strategic elements of pitchers hitting, double-switches, late pinch-hitters, etc. would remain a part of the game, and both leagues would have to change their rules rather than the NL just accepting the dominance of the AL's system. It's also asserted that simply not being the AL-style DH is an advantage. But the normal DH does, or should, promote good defense, as teams will not have to "find a position" for a strong-hitting, weak defensive player by bumping a stronger defensive player from their lineup.

More fundamentally, the argument against the DH is not the "stylistic" one that double-switches are cool. They are, but that's not the point. The old philosophy of baseball was that nine people were playing the game at any one time, and each of them had a "dual mandate": produce offensively and contribute defensively. These two requirements are in tension. In football they don't have dual mandates like this; every player only has one thing they're supposed to do. Baseball requires every player to play both sides of the ball, and earn their keep between the two skills. Some players do this by hitting 40 home runs a year and standing on top of first base with a glove, catching (most of the) throws from the other infielders. Some do this by playing a masterful shortstop or center field, or by being a superb defensive catcher, and holding a respectable batting average in the mid-to-low .200's. Others do it by being a pitcher, which is such a tremendous contribution to the team's defensive effort that it can "carry" a negligible offensive performance.

But the dual mandate is obviously most stressful on pitchers. Put bluntly, it is essentially impossible to be simultaneously a competent Major League pitcher and a competent Major League hitter. Pitching is just too much of a specialized craft; to succeed at it you need to devote nearly zero time to your hitting, which regardless of your offensive talent will make you a lousy hitter. We can see that this dual mandate is orders of magnitude more onerous on pitchers than on any other position player by seeing that, in 2011, National League pitchers hit .142/.177/.184, while the lowest batting average from any other position was the .250 from catchers and the lowest on-base percentage and slugging percentage were the .314 and .374, respectively, from shortstops. The difference between the weakest position at each basic offensive rate state and pitchers was .108/.134/.190, while the difference between the weakest and the strongest position was .021/.036/.077. Pitchers are categorically less able to pursue offensive competence than any other position player.

So the Designated Hitter rule, while it does constitute a distinct and categorical breach of the principle of duality, is by far the most justifiable breach of that principle. Adding a second DH, for the weakest offensive position player on a team, would be a breach of a vastly greater magnitude. Compared to the difference between a pitcher's hitting skills and a shortstop's, the gap between a shortstop and a first-baseman, or an American League designated hitter, is trivial. Subtracting the initial DH would do nothing to dam up this gaping hole in the fundamental principle that people play both sides of the ball. If we're inevitably tending toward the football model, then it's inevitable and there's nothing to do but be sore about it. We shouldn't welcome that move as being preferable to the current DH system, which after all has a great chasm lying between it and the slippery slope of pure football-ism. If the two leagues really are going to give up their league-ness in 2013, and if we can't get rid of the DH altogether, then the best remaining option is just to accept that the DH is in, everywhere, for now.