First things first — by sheer coincidence, Ben Lindbergh wrote about something similar this morning at Grantland. This is a link to the post, and if you missed it, this is another link, and you should read it, and it’s good! It’s never fun to have article overlap, but as I’ve noted before, I’m stubborn about writing ideas, and more importantly, Lindbergh went about doing his research in a different way. So what follows is my own spin on things. It won’t surprise you that we arrive at similar conclusions.
Here’s a theory. The Royals have been successful in the playoffs, right? Already, today, they’ve gotten to R.A. Dickey, not that he’s the ordinary type of postseason pitcher. In the playoffs, the Royals have been able to hit. In the playoffs, pitchers overall tend to be better. A year ago, the Royals were an excellent contact team. This year, the Royals were maybe the best contact team in a very long time. So, does it make sense that being a contact team might provide some sort of playoff advantage? Are contact teams less vulnerable to going quiet against the best pitchers in the game? Not that all the best pitchers make the playoffs, but, you see where this is going. The pitchers are good. Does the offensive style really matter?
We can do this fairly simply. When I examined the Royals’ strikeout rate in a historical context, I assigned to every team a strikeout-rate z-score, for the league in each season. That way, I’m able to account for changing strikeout environments. As you know, strikeouts have gone up an awful lot the last few years, so we can’t just compare numbers directly. Z-scores take care of that.
A z-score shows a number of standard deviations away from the mean. For these purposes, a z-score of -1 refers to a team strikeout rate one standard deviation lower than the league average. The Royals just had a z-score beyond -2. Lots of contact! That’s the whole reason we’re doing this.
For no great reason, I decided to examine the window between 1986 – 2015. I looked at the strikeout numbers for every playoff team, and I looked at the overall regular-season statistics for every playoff team. Then I folded in the playoff statistics for every playoff team. For simplicity, because it’s what’s available on Baseball-Reference, I’ve gone with OPS. I sorted all the playoff teams by strikeout-rate z-scores, and I split them into four groups:
- Z-score of -1 or beyond
- Negative z-score greater than -1
- Positive z-score less than 1
- Z-score of 1 or beyond
You see them in ascending order of strikeout-proneness. Here’s the payoff — how the groups did in the postseason, compared to how they did in the regular season:
|Group||Playoff Games||Season OPS||Playoff OPS||Playoff/Season|
You see the average regular-season OPS, the average playoff OPS, and then the latter divided by the former. This year’s Royals, of course, rank in the lowest-strikeout group. The relative good news is in the last column — that group most preserves its regular-season performance. Every group gets worse; that group gets the least worse. But it’s not a strong effect, and there’s not a clean and clear relationship. Second-best, by this measure: the highest-strikeout group. And there’s no difference at all between the middle two groups. There’s some evidence here, but it’s somewhat weak.
You could very reasonably argue this doesn’t quite capture the current Royals, since their z-score was so far beyond -1. If you draw a line at -1.5, then you get a ratio of 93%. If you draw a line at -2, then you get a ratio of 95%, albeit with a very small sample. But it’s something encouraging. A year ago, the Royals were a very low-strikeout team, and their playoff OPS was identical to their regular-season OPS. The lowest-strikeout team in the pool, this year’s Royals aside, is the 2002 Angels, and they hit much better in the playoffs than they did during the year, and they won the World Series. This year’s Royals have so far out-hit themselves in the playoffs. An example of the opposite would be a couple Indians teams from the mid-90s. They got worse in the playoffs after not striking out much during the year, but this is why we take group averages.
So there really is some positive evidence. It’s not a game-changer or anything, but it at least seems to be relevant, with the Royals swinging well against good pitchers and drawing out at-bats. There’s the one caveat that regular-season numbers aren’t always perfectly reflective of expected playoff numbers. Rosters change, so overall season numbers are only so relevant. But effects should still emerge, if they matter. It seems like there could be a little effect working for the Royals, as a consequence of their contact ability. Even if it isn’t necessarily on purpose, that ability might make them a little more immune to what October sends their way.
Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.