There's a long-standing thought on the Cardinals' offense that they can't hit guys they haven't seen before. This manifests itself in various ways: from Bernie Miklasz criticizing a league-leading offense as "fraudulent" to various VEBers posting permutations of "oh god a soft-tossing AAAA guy; we're DOOOOMED."
This struck me as so much confirmation bias. After all, when you get shut down by AJ Burnett, it's easy to rationalize it as Burnett being a good pitcher with a body of work confirming his talent. When you get shut down by Julio Teheran, your first response may very well be, "Who the hell is Julio Teheran?" Meanwhile, when the team goes berserk and scores a million runs off a guy like Burch Smith, you don't notice; it's just a thing that happens when you have a good offense.
I don't really like narratives that aren't supported by the data, so I set out to demonstrate that Miklasz was wrong: the Cardinals aren't appreciably better or worse against new pitchers.
Problem is, he's right: the Cardinals genuinely do struggle against guys they haven't seen. There is, however, a slight wrinkle: the team does just fine against guys they haven't seen in a while but presumably have video. Rookies, however...they're a huge unhittable mystery.
Looking at every game log this season, I collected data from the opposing team's starter.
You can find that data here:
I could've checked the opposing team's bullpen, too, but this was a manual effort and I didn't much feel like going through guys that might only face a batter here and there.
If the Cardinals hadn't seen that pitcher since before the start of the 2012 season, I flagged them as "unseen." Why 2012 and not 2013? If I use 2013 as my starting point, every pitcher in their first appearance is going to be "unseen." Even a guy like Bronson Arroyo, who's pitched like a million innings against the Cardinals. Including 2012 as the start point seemed right: 7 of the 8 main guys in the offense received significant ABs in 2012. Holliday/Jay/Beltran is the same outfield as in 2012. Freese/Kozma/Carpenter/Craig is 2/4 matched and Carpenter got a lot of work in 2012. Further, Pete Kozma can't hit anyone so I'm not that upset about him being an exclusion. Yadi, of course, is ever-present.
I also didn't count Kyle Lohse since I figured the team was intimately familiar with him. I'm sure it doesn't make much difference, though; Lohse's "new" appearance against the Cardinals was only 1 of 47 to date (Johnny Hellweg was 47 last night.)
Here's the findings:
That's almost a full run per 9 innings difference for the rookies vs. the "not recently seen" guys, and it's statistically significant (p = .05)
What I'm less sure about is the 4.51 ERA being appreciably lower than the Cardinals per-game average. Heading into last night's game, the Cardinals had scored 738 runs in 153 games, for an average runs per game of 4.82.
That's a difference of 0.31 runs per game vs. the "not recently seen group" but it also doesn't account for unearned runs. I only counted earned runs against pitchers in the data set, and I can't find ANY data point that gives me "total unearned runs scored by the Cardinals in 2013." I suppose I could go back through the game logs and compare to the unseen starters, but that's an hour of work that doesn't seem worthwhile. Let's assume for the sake of argument that 4.51 and 4.82 are closer than they appear because I'm not properly accounting for earned runs vs. unearned.
This then leaves us with this conclusion: it's not recency that's the problem, it's the lack of a body of work in an opposing pitcher. I'm not sure what the mechanism is that causes such a difference. Is it an over-reliance on video scouting, and rookies don't have sufficient video?
I also haven't controlled for the ERAs of the rookies. Perhaps the 3.59 ERA vs. rookie starters is a function of "this group includes dudes like Matt Harvey and Jose Fernandez," though I suspect that's not the case.
I'd argue there really is an impact here, and that it's related to the Cardinals' scouting approach. This also means that Monday's game against the Nationals, in which Adam Wainwright squares off against Tanner Roark, scares the crap out of me.