Should the National League adopt it? Should the American League abandon it? Strong, passionate arguments have been made for both sides. So far, though, the issue has never come close to being resolved.
Beginning in 2013, though, there will be another factor to be considered. Once the Astros move to the AL, leaving 15 teams in each league, Interleague Play will no longer be confined to midseason blocks. Out of mathematical necessity, there will have to be at least one Interleague series from the beginning of the schedule until the end.
That changes the discussion somewhat. And it raises the question of whether this should be the impetus to unify the rules once and for all, one way or the other.
Larry Dierker is a former Major League pitcher, manager and broadcaster. He's also an author who currently works in community relations for the Astros. Dierker "absolutely" believes that both leagues should play under the same rules and even offers a creative alternative to the either/or approach.
Dierker's vision is that all teams would carry a designated hitter, who could hit for any player at any time. The twist is that players he bats for would have to come out of the game.
"A hybrid rule where you could hit for the pitcher, but that player had to come out of the game and couldn't come back in, would create nine innings of what the National League is like from the sixth inning on," Dierker explained.
"The first time the pitcher came up, you could have the bases loaded and no one out, and he might be your fourth starter or something. Yet you know you might have to pitch the rest of the game with your bullpen if you do. Or it could happen in the fourth or fifth or sixth, and you'd have tough decisions to make throughout the game, so the strategic implications would make it even tougher on a manager than it is in the National League.
"I would promote that. But even if not, I'd rather have a DH in both leagues or no DH in both leagues. I think it should be unification. But I think there is a better rule than the DH rule."
Jim Thome, who joined the exclusive 600 home run club last season with the Twins, returned to the NL this season. He'll be an occasional first baseman and pinch-hitter for the Phillies. Thome's only conviction is that he doesn't want to see the DH be abolished.
"As a guy that's been a DH, it's so valuable. It lets guys play a little bit longer in their careers where they might not have normally," the 41-year-old said. "I think baseball is trying to make some good changes for the game. I don't want to say, 'Make a change, eliminate the DH,' because it's been such a big part of my career. Especially the latter stages here. But it makes you think about it both ways. It will be interesting to see which direction it goes, that's for sure."
|"I'd rather have a DH in both leagues or no DH in both leagues. I think it should be unification."|
|-- Larry Dierker|
Hall of Fame executive Pat Gillick, who won the World Series in both leagues, would have liked to see this question settled in the bargaining for the most recent Basic Agreement.
"That was one thing I was probably disappointed about in this agreement, that there wasn't some meeting of the minds on the DH," Gillick said. "I mean, it doesn't seem fair to have two different sets of rules. We're one of the only sports that has two sets of rules. And, really, we used to have a very big rivalry between the American and the National leagues. We don't have that same rivalry. It's like we're all one group now. I would just think there should be some agreement one way or the other. Either it's going to be all DH or all National League rules."
Even though Gillick spent the vast majority of his career building AL teams, he would eliminate the DH if it were up to him.
"I was in the American League for a long time," Gillick said. "But I think I like the strategy and I like the way the game is played in the National League. So I would be a proponent of the National League rules."
All of this is fun to kick around. But Michael Weiner, executive director of the Major League Baseball Players Association, said that the people who can actually make a change like that aren't even considering it.
"Both sides recognized when we moved to 15-15 that the arithmetic requires some Interleague Play in each window," Weiner said. "Neither side in bargaining raised a change in the DH rule."
"What people were excited about in terms of Interleague Play, frankly, is with five teams in each division, you can now have a much fairer Interleague schedule. Because each of the five teams in the National League East, for example, will play the same competition in the American League Central or American League West or whoever they're matched up against."
There will be some deviation to account for natural rivalries, of course.
"But with that exception, the vast majority of games the schedules for division rivals will be virtually identical," Weiner added. "It's not going to be 162 out of 162, but it's going to be much closer than it was able to be in a world where you had four, five and six teams in a division to try to match up."
Of course, it also creates a scenario in which a contending AL team could go into a crucial final series of the season and not be able to utilize its designated hitter. But that's a debate for another time.
Paul Hagen is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.