Platoon Power: Breaking Down the Cubs’ Three First Basemen Playoff Strategy

For the first time in five seasons, postseason baseball will include the Chicago Cubs, with the Wild Card Round making its way to Wrigley Field. Chicago is set to welcome in the San Diego Padres in one of two NL Wild Card series, with the winner set to match up with the top-seeded Milwaukee Brewers in the NLDS. 

Playoff baseball being just a day away means it's time to start diving into the analytics and becoming curious about rosters and how in-game situations will play out. One of those situations will be how manager Craig Counsell gets through a game with his first basemen. While it may seem as simple as letting Michael Busch, the team leader in home runs, take every rep, Counsell has shown us this season that Occam's Razor doesn't always apply to his lineup constructions.

Veteran corner infielder Justin Turner was brought in to hit left-handed pitching and play first base, and he's done that somewhat respectably. Against southpaws this year, Turner is slashing .276/.330/.429 with three home runs and a .759 OPS. Those numbers could look even better if you take away his horrific month of April, when he hit just .171 in 41 total at-bats. His postseason experience alone would probably have earned his way into a few starts, but Turner should be a fixture against lefties thanks to his success this season.

So, with that said, the likely scenario would see Busch starting against right-handed pitching with Turner later entering the game to pinch hit against a left-hander. Hypothetically, et's say that happens in the sixth inning of the game; Turner's spot will come up again in the lineup, and it could be against a right-hander such as Jeremiah Estrada or Mason Miller. Who should be expected to take that at-bat? 

Look no further than rookie Moises Ballesteros. One of Chicago's top prospects has collected 57 MLB at-bats this season, and he's looked quite phenomenal doing so. In the limited sample size, Ballesteros is slashing .298/.394/.474, along with a .868 OPS and the first two home runs of his MLB career. He has just 12 strikeouts compared to nine walks, a showcase of his elite plate vision at such a young age.

Up until Saturday, Ballesteros had been strictly a DH for the Cubs. That's now changed, though, as he played an inning at first base both Saturday and Sunday. That would almost certainly indicate that Counsell and the front office envisions a world where Ballesteros would need to play an inning or two at first base in the later stages of games after pinch-hitting for Turner. It would likely be a tough ask, but it may certainly need to be what happens, especially if offense is at a premium against the Padres' otherworldly bullpen.

Everything we've discussed could be rendered moot Counsell decides to stick with Busch against all pitchers and forget about the platoon and the matchup. Given that he just hit .244/.337/.634 (160 wRC+), that could certainly be the case. If not, though, it would seem that Ballesteros's recent appearances at first base have shown Counsell's hand, giving the Cubs an odd-looking but nonetheless effective Cerberus at first base.