The Benefit of the Designated Hitter in Professional Baseball
Craig A. Depken II
Which is the better league: the National League (NL) or the American League (AL)? The debate is perennial. Coupled with this is the debate over the designated hitter (DH) rule and its effect on the playing of baseball. This chapter investigates both questions by utilizing interleague baseball games from the 1997 regular season to estimate the benefit to AL teams when using the DH rule and the relative strengths of the two leagues in head-to-head competition.
In the debate over which league is better, some point to the greater number of World Series championships won by the AL to support their claim that the AL is stronger. Fans of the NL could point out that their league has won more All Star games. While this comparison is a bit more appropriate than the World Series comparison, it is still not clear that All Star game victories prove the relative strength of one league against another.
Moreover, the comparison of World Series championships is faulty for two reasons. First, comparing World Series titles is no more than a comparison between the best team in each league rather than a comparison of all the teams in each league. Second, since 1973 the AL has played under a fundamentally different set of rules with the inclusion of the DH. It was implemented to provide more offense and thus stimulate interest and attendance on the part of fans.
It is not clear that this strategy has been successful in raising offensive output. The average runs per game in the AL is only marginally higher than in the NL ( Butler and Moore, 1996). Moreover, contradictory evidence has been found concerning the effect of the designated hitter on attendance. Domazlicky and Kerr ( 1990) found that attendance was enhanced with the designated hitter, but Butler and Moore ( 1996) did not. Still, it is clear that the DH fundamentally alters the strategies most often