First, in the fifth inning Javier Baez struck Matt Wieters' mask on a passed ball that allowed a run to score. Had the umps properly ruled that the ball was dead after Baez clipped Wieters on his backswing, the inning would've been over. Given that the Cubs prevailed by a single run, the non-call looms large.that
What also looms large is the replay decision that ended the eighth inning. With Jose Lobaton on first and the speedy Michael Taylor representing the potential tying run on second, Cubs catcher Willson Contreras attempted to back-pick Lobaton at first. Lobaton was ruled safe, but the Cubs challenged ...
You get a hint of it there, and additional angles showed that Lobaton popped off the bag momentarily while Anthony Rizzo still had the tag applied. So he was out, and the Nationals lost one of the four outs they had left. First, a slow-footed catcher has no business straying far off the bag when the tying run is 90 feet ahead of him with two outs in the eighth inning. That said, however, this kind of thing strains the purpose of replay.
It's easy to push back against this kind of thing by saying, well, Lobaton should learn to slide/lunge better and not pop off the bag. We also see this on stolen bases all the time. A runner careens into second or third, loses contact with the bag momentarily, and the fielder keeps the tag on and gets the call on replay. The runner beat the throw and tag, but he wasn't able to harness his momentum for an instant. Out.
This, though, stretches the proper jurisdiction of replay, and we need to think about the disincentives in play. In the homer-rich era, in which station-to-station baseball pays off more than ever, do we want another reason not to take chances on the bases? Mostly, though, it's about keeping replay where it belongs. If you look at the replay rules, you'll find that 12 general categories of baseball occurrences are eligible to be reviewed. By implication, a lot that happens on the field isn't reviewable. Ball-strike calls, for instance. Whether the batter clips the mask of the catcher, to cite another somewhat relevant example.
The point is that we've already decided some things are reviewable while others aren't. MLB should add "pop off the bag" plays to the ledger of the un-reviewable. Yes, it's a spirit-of-the-rule argument, and some find such arguments to be too open-ended. Fair enough, but the point of replay is to maximize the number of correct calls while not compromising the game of baseball as a consumer product. When you in essence tell players they need to go into the base half-cocked or not at all, you're tampering with one of the more enjoyable aspects of the sport.
What happened in the eighth inning on Thursday night appeals to those who make a fetish out of the minutiae. Get the calls correct, yes, but only in those instances that still allow baseball to be baseball.