Monday night against the Milwaukee Brewers, Matheny inserted Jon Jay into the center of the lineup in place of the usual starter, Peter Bourjos. Matheny noted that Jay had been 6-for-9 lifetime against the Milwaukee starter, Matt Garza.
Jay responded with a sixth-inning, three-run home run that completely changed the nature of the game. The Cardinals won, 4-0.
Tuesday night, with Mark Ellis returning from a bout of tendinitis in his left knee and available to make his first appearance of the season, Matheny went with Ellis at second over Kolten Wong, who had started 12 of the Cardinals' first 13 games.
"We've been excited about him getting ready," Matheny said of Ellis. "We liked the matchup, too."
Ellis did his bit for the Redbirds, driving in two runs on a groundout in the second and with a sacrifice fly in the fourth, crucial contributions in what was a close game until the top of the ninth. The Cardinals won again, 6-1.
But regarding that favorable matchup, a check of the numbers reveals that, entering this game, Ellis was 1-for-1 lifetime against the Milwaukee starter, Marco Estrada.
The one was a double, by Ellis' own recollection a solidly hit baseball. "It was a double in the [right-center field] gap, I remember those," Ellis said with a smile. "It was in Coors Field. Big gap, though, at Coors Field."
There was more to it than the one at-bat, of course. Looking at Estrada's numbers, Matheny found that Estrada, even though he is right-handed, could be more vulnerable to right-handed hitters, like Ellis.
"It wasn't necessarily Mark's matchup so much as we felt good about right-handers," Matheny said. "He [Estrada] has been left-handed strong the last few years. Righties seem to do OK against him. That was it more so than Mark's 1-for-1.
"We like how Mark goes about it. All things considered, we wanted to get Mark in the Cardinals uniform for real and get him initiated into our club. Mark did a great job, all the little things we talk about."
Matheny studies the individual splits closely. His interpretation of those numbers might be typical in some cases, but it might also be surprising in others.
What works for Matheny in either case is his essential belief in his players.
"You know, when I see a guy who's had even just a couple of at-bats against a pitcher, but has had success, there's usually knowledge on both sides," the manager said. "I don't use the opposite side very well. When a guy has had two at-bats against a pitcher and he's struck out a couple of times, I'm thinking, 'He's going to get him.'
"But if he's had two at-bats and he's had two hits, I'm thinking, 'He owns him.' A lot of it is just how confident our offensive guy would be walking into the box."
So if a St. Louis player is, for instance, 2-for-2 against a particular pitcher, this indicates that the hitter clearly has the pitcher's number. On the other hand, if a St. Louis player is 0-for-2 against a pitcher, this primarily indicates that the hitter is due.
Matheny's view of these small samples appears to be a no-lose proposition for the Cardinals. On the other hand, look what the Cardinals have done in his two years as their manager. They were one game away from the World Series in 2012. In 2013, they had a division title, the best record in the National League and went to the World Series. Expecting success might be the one logical response to any given Cardinal situation.
And there will be numerous occasions when the sample sizes just won't be suitably large, anyway.
"I don't think there is too much of a sample size, or else we'd be waiting around forever," Matheny said. "Every once in a while you see some guys with some larger at-bats, but in general you just take the information that you have and hope that confidence is a big part of that, one way or the other."
One way or the other, Jon Jay was the right choice Monday night. Mark Ellis was the right choice Tuesday night. What becomes more impressive here is not a collection of statistics, but Matheny's judgment.