Last week I attended the SABR Analytics Conference in Phoenix. The Society for American Baseball Research, as I assume you know, is dedicated to researching the game. Many of you are SABR members, as am I. This isn’t an advertisement (though it is a great organization!); I just wanted to provide the background.

The Analytics Conference, as its name implies, is analytically focused. It’s more for baseball numbers nerds than general baseball nerds. That being said, everybody there’s a baseball fan and baseball fans have opinions.

One of their strongest is about the designated hitter. The DH was adopted by the American League in 1973, after a season in which scoring fell to 3.47 runs per game, the fourth-lowest in league history (3.41 in 1968, 3.441 in 1908, 3.443 in 1909). The intent of the DH was primarily to improve scoring, since the changes adopted in 1969 (lowered pitchers’ mound, smaller strike zone) proved to be only a temporary fix.

I don’t need to tell you that the DH has been controversial in each of its 44 years to date. Pro tip: If you’re giving an address to a SABR gathering, or pretty much any group of longtime baseball fans, any riff on “get rid of the DH” is likely to be a crowd-pleaser. Those of us who are OK with it are, in my experience, generally not all that passionate. That’s not always true of the anti-DH crowd.

I’m not here to litigate the DH. That’s not going to get us anywhere. But I do want to point out the trajectory of one of the arguments against it.

There’s the traditionalist argument: Nine players to a side, each plays offense and defense. Making the pitcher a one-way player violates that simplicity. While the slippery-slope-toward-offensive-and-defensive-platoons fear can probably be put to rest, it’s undoubtedly true that pitcher batting skills, never all that good in the first place, have atrophied:

I know, there’s a lot going on there. The key takeaway is that everything’s sloping down.

In a way, this sort of buttresses the pro-DH argument, doesn’t it? I mean, yeah, Bartolo Colon last year, but the pitcher's spot in the lineup has become more or less an automatic out (or, with runners on base, an automatic bunt attempt). There’s not a lot of drama in that.

But that’s not the argument I want to address. I want to talk about strategy.

The DH, it’s argued, robs the game of strategy. Pinch-hitting, double-switches, and everything else that the pitcher’s spot in the order may entail are, while interesting, pretty rote in most cases. But National League managers face a decision that their American League counterparts don’t: Whether to pull a pitcher who’s doing well for a pinch-hitter when tied or trailing.

Take April 14 in the first year of the DH, 1973. In the American League that day two starters, Bert Blyleven and Wilbur Wood, pitched well. Blyleven allowed two runs, eight hits, no walks, and struck out eight while pitching a complete game. Wood also went the distance, allowing three runs (all unearned) on three hits and two walks, with six strikeouts. But both of them took the loss, because Blyleven’s Twins scored only one run against the A’s and Wood’s White Sox scored none against the Royals.

Ah, but over in the DH-less National League, on April 24 of that same season, the Cubs were trailing the Giants 2-1 in the bottom of the seventh inning. Chicago manager Whitey Lockman had to make the tough decision to pull starter Rick Reuschel for a pinch-hitter with two outs and a runner on second. Reuschel had pitched well, allowing two runs and striking out 12 over seven innings, but the team needed to get back into the game. The strategy ultimately failed, as the pinch-hitter, Gene Hiser, flew out. And while the Cubs tied the game in the bottom of the ninth on a Ron Santo home run, Reuschel’s replacement on the mound, Bob Locker, gave up the winning run in the 10th.

If that game had been played in the American League, Reuschel could have stayed in the game and the Cubs may have won. But the desire to keep a successful pitcher on the mound was outweighed by the need to get runs on the board. That’s a decision that American League managers are spared. Ergo, less strategy.

But note that in the examples above from 1973, two of the pitchers went nine innings and the other went seven. In 1973, 54 percent of starting pitchers went seven innings or more. In 2016, that figure was only 23 percent. The decision whether to pinch-hit for a starter in the late innings of a game is a lot easier when the starter’s not in the game anymore! So maybe that aspect of strategy has fallen by the wayside.

Let’s check for that. Here is a graph that shows the innings pitched per starter by league from the beginning of divisional play in 1969. The solid black line is 1973, the year the DH was implemented. (And yes, I realize, these numbers are somewhat polluted by interleague play, but with each team playing only 10 games per season with the other league’s DH rules, it’s not a big effect.)

As you can see, when the DH first came in American League starters did, in fact, stay in games longer than their National League counterparts. Since National League pitchers had lasted longer in the years heading into the DH, we can pretty safely say that the DH allowed AL managers to stick with starters longer. They didn’t have to face the pinch-hitting conundrum when trailing or tied in late innings. DH = less strategy.

But as starting pitchers have yielded to relievers earlier and earlier, the spread has not only declined, it’s vanished. Despite the DH, which in theory allows American League managers to leave pitchers in longer, National League starters have lasted longer in four of the last eight seasons and 11 of the 21 since the 1994-1995 strike. With starters lasting, on average, about 5 2/3 innings, the question of pinch-hitting for the starter in the seventh or eighth inning has become moot.

How moot? Well, as this chart illustrates, AL starters lasted at least a tenth of an inning longer than their NL counterparts in nine of the 14 years beginning in 1974, the year after the DH was established. It’s happened only four times in the subsequent 29 seasons.

But the DH doesn’t create, at least in theory, a strategic difference between the leagues in only starter usage. It affects bullpens as well. Just as a National League manager is more likely than American League manager to pull a starter (for a pinch-hitter) in the seventh inning of a game his team’s losing by a run, so too is the NL manager more likely to bring in a pinch-hitter in the late innings to replace an effective reliever.

In fact, the difference between the leagues in reliever usage was starker, post-DH, than starter usage. In 1972, before the DH, American League relievers averaged 1.59 innings per appearance. National League relievers averaged an almost identical 1.62. In 1973, the first year of the DH, NL relievers pitched an average of 1.54 innings per appearance, but AL reliever innings per appearance zoomed all the way up to 2.06, the highest level since World War II.

American League relievers stayed in games at least a tenth of an inning longer, on average, than their National League counterparts every year through 1988. That year, Dennis Eckersley recorded 21 one-inning saves under Tony La Russa’s American League champion A’s, and the trend to one-inning relievers was ignited. Have shorter relief outings yielded less of a difference between the leagues? Yes they have:

American League relievers still stay in games a little longer than National League relievers, but the difference hasn’t exceeded a tenth of an inning pitched since 2003, as this graph illustrates.

If you don’t like the DH because you think the two leagues should play by the same rules, fine. If you think everybody on the field should play on offense and defense, that’s OK. If you think it’s fun to see Bartolo Colon hit, you’re entitled to your opinion (as well as his .068/.083/.101 line excluding his May 7 homer).

But if your objection is that the DH robs the game of strategy, you’re fighting an outdated battle. The complaints about modern pitching staffs—starters who can’t pitch deep into games, a parade of relievers who last only an inning at a time—have all but eliminated the decision National League managers used to face about keeping a pitcher in the game or pulling him for a pinch-hitter. In today’s game, the pinch-hitter’s going to bat regardless, because the pitcher he’s replacing is done for the day. The strategic decision’s not on the table the way it was in 1973.