It’s No Coincidence Playoff Hitting Is Down

You might’ve noticed there hasn’t been much in the way of hitting lately. As always in the playoffs, the samples are small, but numbers are numbers, and I was thinking about putting together a post on the subject. Then Dave put together a post on the subject! He addressed a lot of what I wanted to address, so, go ahead and read that. Relative to the regular season, playoff hitting has so far come in surprisingly low. Or, maybe not so surprisingly low, if the image you have in your head when you think about the playoffs is the face of Andrew Miller.

When I was thinking about my original post, I envisioned a plot much like the one Dave included. What I did instead was dig a bit deeper. In reality, you can’t so easily just compare playoff teams to teams in the regular season, because the teams and players alive in October belong to subgroups. What if you just examine the subgroups? So, that’s what this is.

So much of this was made possible by the Baseball-Reference Play Index. Use it and love it. It’s great! I used the Play Index here to examine playoff players in the wild-card era, stretching back to 1995. I wanted to know about the true talent of playoff hitters, so for every playoff player in every year, I found his regular-season wRC+, and then I weighted by playoff plate appearances. Here now are the “actual” year-to-year playoff league wRC+ marks.

I don’t think I’ve done a great job of explaining this. Let’s take 2016. The line for 2016 settles on a wRC+ of 108. That means that the players who have batted so far in the playoffs averaged a regular-season wRC+ of 108, once you weight by playing time. It shouldn’t be a surprise the group is better than average, because better players than average make it to the postseason. And, yeah, I could arguably do even better than this by folding in a wRC+ projection instead of a single-year sample, but, I can’t imagine that would add very much.

What we see here is fairly stable. Playoff hitters sort of hit a trough there in 2005 – 2006, and they peaked in 2011, but there’s not so much volatility. The average over the whole era is 109. This year’s 108 is right there. Playoff hitters, overall, are about 8 – 10% better than average, as they should be. There’s not so much room for your utility or Quad-A types when the games are so important.

After I finished looking at hitters, I turned my attention to pitchers. Following pretty much the same methodology, I looked at both ERA- and FIP- for the regular seasons, this time weighting by playoff innings. You’re with me? You’re with me! Here’s the goods.

Remember that an ordinary playoff hitter is around 9% better than average. By ERA, an ordinary playoff pitcher is around 20% better than average. By FIP, an ordinary playoff pitcher is around 14% better than average. This is one of the reasons why run production is almost always down this time of year — the pitchers are simply better than the hitters, relative to what’s usual. Why the gap between ERA- and FIP-, here? Part of it’s probably just selection for lower ERAs; lower ERAs are sexy, and lower ERAs help get teams to the playoffs. There’s also the probability that playoff teams have slightly better defenses than average. Defense is the least-important team component out of the three major ones, but it should still be somewhat positively correlated with success.

Focus now on 2016 in particular. This month’s playoff pitchers averaged a weighted regular-season ERA- of 72. That’s the lowest mark in the whole era. This month’s playoff pitchers also averaged a weighted regular-season FIP- of 80. That, too, is the lowest mark in the whole era. The average playoff hitter has the same wRC+ as Gregory Polanco. The average playoff pitcher is more like Masahiro Tanaka or Max Scherzer. The pitching has gotten really good, and as Dave brought up, at least part of this presumably has to do with more aggressive bullpen use. The more teams are able to use their best relievers, the harder it’s going to be to score runs. That’s obvious, and I’m guessing it’s going to be part of a trend.

To close out, we should be able to blend the two plots above. wRC+ is on the same scale as both ERA- and FIP-, so I decided to add the marks together for each year. I’m using this as a measure of playoff-specific run environment. If the numbers were to add up to 200, that would be a perfectly average run environment. Anything below 200 would favor the pitchers. Here you are:

For 2016, wRC+ and ERA- add up to 180, which is below the era average of 189. The previous low was 184. And, wRC+ and FIP- add up to 188, which is below the era average of 195. The previous low was a very similar 189, but that came back in 1996, which is two decades into history. This year’s playoff run environment is the toughest it’s been, at least so far. So it’s not a shock that hitting has been suppressed, and I’d say some of this is because of how bullpens have been used, and some of this is simply about how the players and their talents are distributed. Perhaps the playoffs just have better pitchers than usual this time. There’s plenty of room for randomness.

But the bullpen thing — that’s probably not going away. That’s going to be a trend, because it already is a trend, and it’s going to make hitting in October all the more tough. Offense does still exist. Good hitting does still exist. It might just be wise to adjust expectations. You shouldn’t expect hitters to have the same numbers after the calendar flips. The playoffs are practically a big giant All-Star Game.