There has been a lot of snark, in the wake of the Yankees' loss in the ALCS, about Joe Girardi and his little binder of pitcher-hitter matchup data (the use of which, as
John (New York, NY): Rob, the sample size of batter/pitcher matchups is of particular interest to me. Obviously a sample size of 5-10 PAs against a single pitcher does not yield any useful data. However, when you consider that in those 5-10 PAs, a single batter is only facing the repertoire of a single pitcher, my question is how many PAs are required before the data becomes significant? 20? 50? More? What do you think?Later, another New Yorker had a follow up:
Rob Neyer: More than 20. I'm not sure if 50's enough. I'm not sure if any batter has ever faced a pitcher enough times to show us anything truly meaningful. I think what makes more sense is looking at how a hitter has fared against *types* of pitchers.
Jeff (NY): While I agree that 0-20 from one batter against one pitcher is too small of a sample size, aren't the odds higher that the batter will continue to struggle than if he were 0-2? I don't think varying degrees of samples, with regards to educated predictions, is talked about enough. For example, 0-5 is meaningless, 0-10 is less meaningless, etc. Does this make any sense? Is there any research I can read on it?This piqued The Common Man’s curiousity, and he did some digging through Baseball Reference’s Play Index function to see just how much exposure a batter could get to a pitcher. First, though, a couple notes.
Rob Neyer: I don't know of any research, but yes I would assume you're correct: 0-20 is more useful than 0-2. The question is whether or not 0-20 is useful enough to use.
- The Play Index only has play-by-play data as far back as 1950, so all figures are from 1950-2010. This means that a few of the pitchers TCM looked at here (such as Warren Spahn, Robin Roberts, and Billy Pierce) have incomplete data.
- Second, TCM limited his examination to the Top 60 pitchers (measured by Innings Pitched) of the last 60 years. This is convenient for a number of reasons. For one thing, it limits the pool to a manageable size. For another, there are exactly 60 pitchers who have, since 1950, thrown more than 3000 innings in the Major Leagues. And finally, the opportunity for pitchers with fewer than 3000 innings to face a batter enough times to be significant is incredibly low.
- And third, TCM listed all batters who had more than 150 plate appearances against these pitchers, as well as a few select matchups that occurred 100-150 times that were particularly interesting.
Some of the results are not terribly surprising (you can look at TCM's spreadsheet here, if you want to look at the data yourself). First and foremost, 23 pitcher-batter matchups occurred more than 200 times each. Of these, only one of the pitchers and one of the hitters involved debuted after the 1963, Phil Niekro (1964) and Johnny Bench (1967). The reasons for this should be intuitive. Baseball has expanded greatly since 1961, meaning that batters and pitchers have had fewer opportunities to square off against one another. Also, since the onset of free agency in 1976, players have been far more mobile during the prime years of their careers, allowing them to switch leagues while they are still playing regularly. This, too, decreases their chances of facing any single pitcher. Finally, the use of the bullpen has evolved tremendously since the heyday of complete game madness in the 1960s and early 1970s. When starters leave the game early, naturally batters get fewer cracks at them.
The most common matchup since 1950 also shouldn’t surprise us too much. Phil Niekro, the veteran knuckleballer, leads pitchers during this time with 5,404 IP. Likewise, Pete Rose is the all time record holder in plate appearances with 15,861. Rose debuted in 1963, and played his entire career in the National League until his retirement in 1986. Knucksie debuted, as TCM mentioned, in 1964 and spent almost all of his career in the NL until he left for the Yankees in 1984. Over the 20 seasons they were in the same league, Niekro and Rose faced each other 266 times, with Rose hitting .283/.384/.363 with 2 homers. These are somewhat down from his career line of .303/.375/.409, but are actually a significant improvement over Niekro’s typical opponents, who hit .247/.311/.366 in his career.
As a side note, it’s also important to point out that Warren Spahn and Stan Musial faced each other 260 times from 1950 until Stan the Man’s retirement in 1963. However, Spahn played briefly in 1942, and established himself in 1946. Musial was a star from ’41-44, and came back in ’46 as well. The two undoubtedly faced each other far more than 260 times, blowing them well past Niekro and Rose. Musial hit a robust .323/.417/.556 with 8 homers off Spahn from ’50-’63. Also, depending on how many times Robin Roberts squared off against Duke Snider in 1948 and 1949, that pair may also have surpassed Niekro and Rose.
Speaking of Snider and Roberts, during our time frame, Snider hit 18 homers off of Snider, which is tied for the most on the list with Willie Mays and Warren Spahn. Snider did it in three fewer appearances though (247 to 250), and may well have homered of Roberts prior to 1950. There is no solid evidence of this, but TCM guesses Snider probably has the most homers any batter has hit off of one pitcher in baseball history.
Snider’s .623 SLG off of Roberts, however, is nothing compared to the abuse other batters have dished out. Ernie Banks also owned Roberts, hitting .339/.377/.793 with 15 homers off of Robin in 130 PAs. Stan the Man hit .381/.424/.694 off of Roberts from 1950-1963, though probably did additional damage in ’48 and ’49. But nobody owned Roberts like Mike Schmidt owned Jerry Reuss. Over 115 PAs, Michael Jack slugged .863 off of Reuss, with 11 homers. Schmidt also hit .411 off of the lefty, and had an OBP of .504.
The pitchers, though, had their revenge too. Don Drysdale absolutely owned Eddie Matthews, who hit just .194/.275/.335 with 7 homers over 229 appearances. Likewise, Willie Davis was completely lost against Juan Marichal in exactly 200 PAs, hitting just .181/.191/.321.
And all the stories about Whitey Ford dominating the White Sox were absolutely true. Nellie Fox, a career .288/.348/.363 hitter, hit .215/.268/.238 against The Chairman of the Board in 197 PAs. Luis Aparicio was just as bad, hitting .234/.260/.292 in 178 trips. And Minnie Minoso hit .262/.347/.324 in 169. Only Al “Fuzzy” Smith had anything approaching success against Whitey, hitting .262/.363/.421, or just around his career line.
For reasons The Common Man laid out earlier, pitchers from the last 20 years don’t often show up on this list. Indeed, Greg Maddux is the only hurler from this decade who has faced a batter more than 150 times. Maddux faced Barry Bonds 157 times from ’86-07, a span of 22 season when both were exclusively in the National League. It’s an instructive contrast with Niekro and Rose, who spent 20 years squaring off, and still managed to pair up more than 100 times more than Maddux and Bonds. As you’d probably expect, Bonds had success against Maddux, but fared far worse than his career line, hitting ..265/.376/.508 with 9 homers. The man who really owned Maddux was Luis Gonzalez, who hit .325/.381/.618 with 10 homers in 135 PAs.
Maddux and Craig Biggio also locked horns more than 150 times (152), but Bidge had far less success, hitting .284/.331/.369. Biggio also struggled mightily against Tom Glavine (.234/.323/.351 in 127) and John Smoltz (.239/.297/.316 in 128) in significant exposure.
But this doesn’t really speak to Rob’s concern. How many plate appearances does it take for a player’s performance to be considered truly predictive? Even Rose’s 266 shots at Phil Niekro constitute something around 60 games tops. Through his first 267 plate appearances (across 65 games) in 2010, Detroit’s Brennan Boesch hit .342/.397/.593 with 12 homers. The rest of the way, he hit .163/.237/.222 with 2 homers in 245 more trips to the plate.
One could, TCM supposes, make the argument that batter/pitcher matchups are less prone to streaky runs by batters or pitchers, because the matchups are more spread out over time. Indeed, the kinds of fluky stretches players experience are even less likely as pitchers begin to know more about the hitters. After all, one of the reasons Boesch seemed to fall apart for the Tigers was that pitchers learned how to pitch against him. If a batter or a pitcher has sustained success against another over 100 or 150 or 200 plate appearances, one could assume that that dominance is informed by all the exposure that has come previously.
And the players involved in these matchups also have a sustained baseline of Major League performance we can reference to inform us about their abilities. We know, for instance, that Willie Mays was a good player, regardless of his hiting just .196/.315/.304 against Bob Gibson, which makes Gibson’s performance more impressive. And because of this, TCM thinks it’s likely that the results are more trustworthy in these cases when they are more extreme. Joe Morgan’s .226/.335/.415 against Don Sutton in 191 PAs isn’t particularly instructive, as it appears his plate discipline and his power are relatively intact. The main difference seems to be a few extra balls in play that were converted into outs. Meanwhile, Ron Fairly’s .302/.369/.440 performance against Bob Gibson in 179 PAs seems to be more likely the function of a few extra singles and doubles falling in.
So where’s the line? TCM is tempted to put the number around 150, though obviously 200 is even more instructive. The trouble, as you can see above, is that players are increasingly unlikely to hit that mark in today’s game, making Hitter vs. Pitcher data little more than a fun exercise.
(Note: By the way, The Common Man’s favorite part of this project was looking at Bert Blyleven. When people argue against Bert for the Hall of Fame, they often make the case that he wasn’t a dominant pitcher, merely very good for a long time. The Common Man disagrees, and presents into evidence the ownage Blyleven meted out against three men who faced him more than 100 times. All of them are Hall of Famers. Reggie batted just .214/.264/.397 with 6 homers against the Dutchman in 140 chances. The immortal George Brett hit .231/.281/.342 with just 2 homers in 128 PAs. And, worst of all, Robin Yount mustered just .182/.211/.300 in 114 trips against the merely “good” Blyleven. That’s Hall of Fame dominance against some of the best hitters of the 1970s and 1980s.)