We’re to the point now of there being less baseball, which means we’re to the point now of there being more important baseball. The stakes are the highest they’ve been, and all those little managerial decisions people love to complain about during the regular season might at last be worth actually complaining about, because the leverage of everything is suddenly through the roof. Every little decision now could conceivably contribute to a team winning or not winning the World Series. Thursday, we all got news of one decision in particular — for Friday’s Wild Card playoff against the Cardinals, the Braves will start David Ross at catcher instead of Brian McCann.

It feels weird to imagine the Braves deliberately benching McCann at a time like this, where one game will decide whether there are subsequent games. McCann’s long been the regular in Atlanta, up to and including this season, and by and large he’s been a terrific one. You’d think that a team would go with its trusted regulars in a one-game playoff, no matter how much it also trusts its backups. But it’ll be David Ross catching Kris Medlen and the relievers, and more, the decision seems sound.

We should begin by noting why this decision was made in the first place. Fredi Gonzalez:

“[McCann’s] been banged up here for a while. God Bless him. In the one-game series, you go with Rossy. In the longer series, (McCann) is going to play. He’s not that banged up that he’s not going to play.”

McCann seems like he’s destined for offseason shoulder surgery, to fix up something he’s been fighting through almost all year. Gonzalez also took care to highlight Ross’ defensive advantage over McCann, as Ross throws out an awful high percentage of would-be base-stealers. So it’s a decision that’s been made with defense in mind, but not exclusively. Now we analyze!

Even though Friday’s game is the only game, and anything can happen in a single given baseball game, we have no choice but to analyze by probability, by looking at the overall picture. The best thing the Braves can do is increase their odds of winning and advancing to the Division Series. Odds are all you can control, and single games can be crazy.

The Cardinals will be starting Kyle Lohse on the mound, and Lohse is a righty. David Ross bats righty, and Brian McCann bats lefty. Instantly you’d think the Braves would want to go with the guy with the platoon advantage, but it isn’t that simple. (Assume it’s never that simple.) Lohse, the last two years, has posted no platoon split at all. Ross, for his career, has posted no platoon split at all. McCann has a platoon split, but he’s also banged up, implying that he’s not at 100 percent. We can’t just look at McCann’s career performance, because we have relevant and recent information.

Against righties, McCann has a career 123 wRC+, and Ross has a career 99 wRC+. But Ross hasn’t posted a wRC+ below 100 against righties since 2007, and McCann’s split in this particular season, this season in which he’s been playing hurt, is 89. Ross, this year, came in at 120. The long-term splits tell you one thing; the more recent splits tell you the opposite, and we should more heavily weight the more recent splits. It matters that McCann has been and still is injured.

Defensively, Ross does indeed have an advantage in terms of controlling the running game. Opposing teams have attempted about 0.9 steals against McCann per nine innings, and he’s thrown out 24 percent of runners. Opposing teams have attempted about 0.7 steals against Ross per nine innings, and he’s thrown out 39 percent of runners. Contrary to what Gonzalez said, the Cardinals aren’t a big stolen-base team, but it’s still a factor and one figures that in a one-game playoff, the run environment will be lower than usual, so extra bases will be more important than usual. Ross is the better bet in this department.

By pitch blocking, there doesn’t seem to be a real significant difference between the two guys. And though I recalled off the top of my head that Mike Fast found McCann to be a pretty good pitch-framer, it turns out Fast found Ross to be an even better pitch-framer. There isn’t enough precision in that data for us to declare outright that Ross is better than McCann at receiving, but we can’t say that he’s worse. He seems to be very similar.

When you put it together, Ross makes a lot of sense. In order to side with McCann, you have to believe that McCann’s a better hitter than he’s shown, but someone who’s hurt is likely to underachieve and McCann’s been playing hurt and underachieving. In terms of one-game win probability, the difference between starting McCann on Friday and starting Ross might be something like one or two percent, if even that, but every little edge is an edge. You don’t want to get eliminated and wonder whether you tried your hardest not to.

There is something kind of troubling here, though. Gonzalez intimated that, if the Braves win Friday, McCann will go back to getting the bulk of the work in the playoffs. He’s the regular, and he should remain the regular, or something. Seems to me that if Ross is the guy Friday, Ross should be the guy most days. Gonzalez has determined that starting David Ross on Friday increases the Braves’ chances of winning. Why should anything about that change in a playoff series? But for one thing, we can’t criticize someone for something until that someone actually does that something, and for another, maybe Ross isn’t capable of playing that often, since he’s a backup. Plus, you can get into the intangibles of benching a trusted regular at the most critical stretch of the year. I don’t know how that would go over and I’m not going to speculate.

David Ross is a pretty underrated backstop. In a huge spot, he’s got the trust of his manager, and while the catchers might end up making hardly any difference on Friday, Ross could in theory make all of the difference. It’s all just about the odds. Relative to Brian McCann, Ross seems to have pretty good odds.