A-Rod’s Postseason Problem

In a recent post I discussed my analysis of the why some hitters bring their “A” game into the postseason, while others seem to take it down a notch or two. My analysis does not deal with a player’s makeup or psyche, or how they handle pressure, nor does it have anything whatsoever to do with the topic of clutch performances. I’m coming at this from a different angle, with a data-based look at how hitters perform against different strata of pitching quality. The reason this analysis may have implications for a hitters’ postseason performance is the quality of pitchers in the postseason differs (by a lot) from regular season pitching. My hypothesis is simple—hitters who have a track record against top pitchers will survive or even thrive in the postseason, while those who are systematically beaten down by top pitchers will have a tough time shining in October.

On average, hitters follow a pattern—they perform at their average level versus “average” pitching, better against “weak” pitching, and worse against “top” pitching. Using OPS as a calibration point, hitters hit about 80 to 100 points lower against the top one-third of starting pitchers and about 80 to 100 points higher against the bottom 33%, on average.  Not everyone follows the same pattern. Some are particularly effective against top pitchers and hit only marginally better against weak pitching. Others have the opposite profile—they exploit weak pitching, while being stifled by top pitching. Alex Rodriguez profiles in the latter group. Because postseason pitching tends to be comprised of more top tier pitchers, (see my previous post) we can expect players like A-Rod to produce at a lower level during the postseason.

Let’s start by looking at Alex Rodriguez’s regular season hitting versus different quality levels of pitching. I created an index of a player’s OPS relative to the MLB average, against top pitching and weak pitching. If a player indexes above 100 he performs relatively better against top pitching; if he indexes below 100, he performs relatively worse against top pitching. A-Rod indexes at 92, while Derek Jeter indexes at 114. Mark Teixeira, who has also had his postseason struggles indexes at 94, while Robinson Cano comes in at 109. For perspective, one of the highest indexes for any player currently in the postseason is Carlos Beltran, who scores a 121 on this measure. Is it a coincidence that Carlos Beltran crushes high quality pitching—in 115 postseason plate appearances he has a 1.297 OPS? Several other marquee players currently in the postseason are listed below:

Let’s compare Jeter and A-Rod’s actual postseason performance over their career. We can’t simply look at all regular season stats vs. postseason stats, since a player may have reached the postseason in his best or worst hitting seasons. Instead, I weighted the player’s regular season OPS based on the number of plate appearances in each year they reached the playoffs. This gives us more of an apples-to-apples comparison. For his career (prior to this postseason), A-Rod have a blended average .945 OPS for the regular season and an .884 OPS in the postseason—a downgrade of 61 points. Conversely, Jeter’s regular season numbers are .830, with a postseason OPS of .839. Here’s an instance where the actual performance, over a 15-year career, supports the analysis of who succeeds in the playoffs.

Over the course of a postseason a player may have a hot or cold streak, so the small sample size means this framework may not translate in the short run. A-Rod proved that with his 2009 postseason as he carried the Yankees to a World Championship. Nonetheless, the approach of determining whether or not a hitter crushes (or flounders) against top pitching may provide a window into their postseason performances.


  1. hlang

    How can you believe that a postseason OPS of .884 indicates a worse performance in any sense than a postseason OPS of .839? Both are really good OPSs, by the way. And sample size is an entirely plausible explanation variation from regular season performance. You could clip any random set of 3-19 games from each season in a guy’s career and get similar results.

    • Vince Gennaro

      Hilarie–thanks for your comment. First, let me be clear. Jeter will never be the hitter A-Rod has been over his career. As good a hitter as Jeter is, it’s not even close. My point is that A-Rod will not perform at his full talent level in the postseason because his “game” does not fit well with the characteristics of the postseason. Think of it as a different “league”…like MLB-squared…or something like that. The difference between the quality of hitters in the regular season vs. the postseason is relatively small. Teams can’t do anything to rearrange the amount of plate appearances a hitter can get…the stars will each get about 11% of the at bats. Pitchers are entirely different, which allows managers to deploy pitchers to make the quality of pitching nearly “twice as good” in the playoffs. A-Rod over his last 1500 plate regular season appearances, has struggled against good pitching and crushed weak pitching. In over 300 PA against top pitchers, he’s had a .760 OPS. In over 300 PA against the worst pitchers, he’s had an OPS of 1.030. That 270 point spread is much wider spread than the average hitter. Jeter’s comparable #’s are .770 against top pitching and .825 against the worst–a spread of only 55 points. The average spread between how hitters fare against top vs. bottom pitcher is about 180 points.

      To your second point, A-Rod’s postseason consists of over 300 PA’s and Jeter’s is over 700 PA’s. It’s a pretty large sample size and the fact that they are under the same playoff “conditions”, makes them not random.

  2. Pingback: Why It’s A Mistake To Count On A-Rod This Post-Season | WasWatching.com
  3. David

    I think next year A-Rod will return back to his normal self. If he doesn’t get traded, he’ll still have to prove himslef like a rookie since his lack of perfomance. He needs to really work hard. I was wondering if you could check out my blog. Come and see a kid’s view on all things baseball. Feel free to offer any advice and to pass it along.


  4. Anthony A. Perri

    Vince, great stuff here. Enjoyed the your appearance on MLB Confidential this evening. Do you have a link to the data showing how all of the hitters in this period fared against the different tier of pitchers? This is valuable information for the fantasy community.

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