It’s become an in-game joke, but not one without data to back it up: if you want to stifle the Cubs’ bats this year, just go ahead and load the bases.
As a team, the Cubs are hitting .224/.333/.396 this year, which certainly ain’t great, but it is at least precisely league average by wRC+ (100). But when the bases are loaded – when the typical team actually hits much better thanks to the need to come into the zone, the stress on the pitcher, and the lack of shifts – the Cubs are hitting .182/.211/.182, with a 9 wRC+. Yes. Nine. As in 91% worse than the league average hitter in an average situation.
To be fair, it’s still not a TON of plate appearances, so you can draw only so many overall conclusions from 38 such situations. On the other hand, that’s the 4th most PAs with the bases loaded in baseball, so the Cubs have certainly given us plenty of opportunities to be maddened beyond belief.
Here’s the real kicker: the Cubs have actually been above-average at the plate with runners in scoring position, and that data includes the bases loaded situations! So that means, when the Cubs have a runner at second and/or third, they’ve been great! But suddenly, when that extra runner gets to first base, they’ve become the worst hitting pitcher on your team!
This probably won’t last, at least not to this degree, but you also do worry at some point about it getting in guys’ heads – up there thinking about finally being the guy who does real damage with the bases loaded. So I guess if you’re a Cubs player, just ignore all this stuff, and leave it to us to freak out and make jokes.