Why Everyday Interleague Play Screws the NL

With the Houston Astros move to the American League West, the American League and National League both have 15 teams again. In one sense, this makes things more equitable, as now each team has to overcome four division rivals to guarantee themselves a spot in the playoffs. Under the old system, NL Central clubs had to beat out five other contenders, while AL West clubs only had to best three of their opponents. The more teams you have fighting for the same playoff spot, the less likely each one is to come away the victor, so shipping an NL Central team to the AL West could be seen as a move to make things more fair.

However, there’s an unintended consequence to having 15 teams in both leagues; mandatory interleague match-ups nearly every day. Under the old 14/16 arrangement, MLB would confine interleague match-ups to several distinct periods, where nearly every game was an interleague match-up for a week or two. Now, each team has to deal with randomly dispersed interleague match-ups, and this change puts several NL teams at a real disadvantage.

With random interleague match-ups, NL teams no longer have the luxury of adjusting their rosters to prepare for road trips to AL cities. Previously, an NL club could stash a decent hitting first baseman in Triple-A, call him up for the week or two of the season where a DH was going to be necessary, and then go back to having their regular DH-less roster for the games against their NL opponents. This format puts three game trips to AL parks in the middle of otherwise normal parts of the schedule, leaving the senior circuit teams to wage interleague warfare with their NL rosters.

There are a few National League clubs who will do just fine. The St. Louis Cardinals, for instance, have a roster that is perfectly adaptable to American League baseball. With power hitting Matt Adams (a career 114 wRC+ in his limited major league time) sitting on the bench behind starting first baseman Allan Craig, they have a classic DH already on their roster. Or, if they wanted, they could simply shift Matt Carpenter — who is transitioning to second base simply because the Cardinals have too many good hitters and he needs somewhere to play — to the DH spot, upgrading the team’s infield defense without taking one of their regular bats out of the line-up. In fact, the Cardinals may be a better team in AL parks than they are in NL parks, simply because of the extra flexibility that having a DH would give them.

Likewise, the Washington Nationals will be just fine when they they swap out their pitcher for another bat, as they have 26-year-old Tyler Moore and his .256/.320/.500 career line to insert into the batting order. 19 of Moore’s 41 hits went for extra base hits in his rookie season last year, so he’ll provide another source of power when the Nationals head for American League cities. As if the Nationals didn’t already have enough offense already.

However, there are other NL clubs who don’t have ready made Designated Hitters, and are going to be at a real disadvantage when they have to make a decision on how to use their bench to replace the pitcher in AL parks. The Atlanta Braves, for instance, have two games in Toronto at the end of the month, and if Brian McCann’s shoulder isn’t ready for him to come off the DL by that point, they’re going to have to make some interesting decisions.

Their bench currently consists of a catcher (Gerald Laird), two utility infielders (Blake DeWitt and Ramiro Pena), and a pair of reserve outfielders (Reed Johnson and Jordan Schafer) who would have a hard time scaring a child into handing over their candy, much less intimidating a big league pitcher. The guys on the Braves roster who fit the DH profile are currently needed to play the field, and so Atlanta’s sole option may be to use those games as a day of rest for their defensively challenged starters, while Toronto gets to roll Edwin Encarnacion out there in the middle of their line-up.

The DH issue has long given American League teams an advantage in head to head match-ups, which is one of the reasons AL clubs have won 52.4% of all the interleague games played since 1997. Now, though, the everyday interleague game means that NL teams will have even less of a chance to adjust for their excursions to the lands where pitchers don’t hit. The pain won’t be felt evenly, and NL clubs who happen to be carrying an extra bat to begin with will have a more significant leg up during those games than their NL foes. The difference might not seem all that meaningful, but when division races are decided by a single game, every little margin matters. If the Cardinals or Nationals end up squeezing out a division title on the last day, it might just be due to the fact that they have a roster built for a fair fight in American League ballparks.