Tuesday, April 10, 2012
The Decline of Left-Handed Batters
Once upon a time, Major League Baseball was dominated by left-handed hitters. From the early 1900s on through the conclusion of World War II and the end of the color line, almost all of baseball's greatest hitters swung left-handed: Ty Cobb, Tris Speaker, Shoeless Joe Jackson, Home Run Baker, Eddie Collins, Babe Ruth, Lou Gehrig, Mel Ott, Ted Williams, Stan Musial ... I mean, holy cow.
Yeah, there are some great right-handed batters from that era: Rogers Hornsby, Jimmie Foxx, some smaller stars. But the big guns were almost all lefties. That is emphatically not the case today. More and more, right-handed batters stand out at the plate. I'm not saying that left-handed hitters are disappearing, but they're clearly not dominating the game the way they once did.
There's a simple way to show this: rWAR. Baseball-reference.com provides yearly rankings based on Offensive Wins Above Replacement. For decades, the list is topped by left-handers, and that's no longer the case. I freely admit I'm cherry-picking these dates, but from 1911-1948, the top three in Offensive WAR included 82 left-handed hitters, 31 right-handed hitters, and one switch-hitter (Augie Galan in 1945, because I know you were wondering). That's more than 2½ times as many left-handed hitters as right-handed.
In the 63 seasons since, the top three has included 113 right-handed hitters, 66 left-handed hitters, and 11 switch-hitters. That's 71% more righties than lefties. Even if you set the dates to historical events — say, the start of the modern World Series to the end of the color line (1903-46) instead of 1911-48 — that's basically the same thing. The percentages don't change very much. We're talking about 100 years here. This isn't just Babe Ruth and Ty Cobb skewing the rankings, any more than it's Albert Pujols skewing them now. Left-handed batters just don't dominate the way they used to.
Below are the top 15 in wRAA (Weighted Runs Above Average) from the last 20 seasons (1992-2011), via FanGraphs. Left-handed batters are listed with an asterisk, and switch-hitters in italics.
1. Barry Bonds*
2. Manny Ramirez
3. Alex Rodriguez
4. Jim Thome*
5. Albert Pujols
6. Frank Thomas
7. Todd Helton*
8. Chipper Jones
9. Gary Sheffield
10. Jeff Bagwell
11. Larry Walker*
12. Edgar Martinez
13. Jason Giambi*
14. Lance Berkman
15. Vladimir Guerrero
Four of the next five are lefties, but the list is composed mostly of right-handed hitters. Do the same thing for any period before 1960, though, and you'll get a list heavily populated by hugely successful left-handed batters. Here's 1911-30:
1. Babe Ruth*
2. Ty Cobb*
3. Tris Speaker*
4. Rogers Hornsby
5. Eddie Collins*
6. Harry Heilmann
7. Joe Jackson*
8. Lou Gehrig*
9. George Sisler*
10. Zack Wheat*
11. Ken Williams*
12. Al Simmons
13. Jack Fournier*
14. Hack Wilson
15. Jim Bottomley*
That's 11 left-handers, including all of the top three and eight of the top 10. From 1931-50, you get 10 lefties in the top 15, including three of the top four. Here, easier in a chart:
Top 15 in wRAA
This is not a sudden, dramatic decline. But it's not a fluke, either, and it appears to be accelerating. In the last seven seasons, the top three in Offensive rWAR has included 19 right-handed hitters and just one each switch-hitter (Carlos Beltran in '06) and left-handed (Josh Hamilton in '10).
So the dominance of left-handed batters has waned. But why? The short answer is: I don't know. But I have several theories.
1. Increase in switch-hitting
There still are not a lot of switch-hitters in baseball, but there are more than ever before. In the past, it was not unusual for naturally right-handed players to bat left-handed. Most of those guys are switch-hitters now. Right-handed players who hit left-handed included Home Run Baker, Yogi Berra, Wade Boggs, George Brett, Rod Carew, Mickey Cochrane, Eddie Collins, Charlie Gehringer, Eddie Mathews, Johnny Mize, Joe Morgan, and many others. It's far less common today for a right-hander to drop his natural preference at the plate entirely, so some potentially great left-handers have instead become great switch-hitters.
Prince Fielder and Joey Votto both throw right-handed but hit from the other side of the plate, so this practice obviously isn't extinct, but the trend is more toward switch-hitting than just batting lefty. In 1951, the top 50 in OPS+ included one switch-hitter, Sam Jethroe. In 2011, the top 50 in OPS+ included nine switch-hitters.
2. Base-running
The statistics I've been citing — wRAA from Fan Graphs and Offensive WAR from Baseball Reference — both include base-running, something not affected by which side of the plate you bat from. The wRAA leaders from the '80s included Rickey Henderson and Tim Raines, good batters who made a lot of plate appearances and drew a lot of walks, but also two of the most accomplished base stealers in history. The inclusion of base-running probably skews the numbers a little.
3. Left-handed relief pitchers
Relief pitching is a bigger part of the game than ever before, and many pitching changes are designed to gain the platoon advantage. Research suggests that most of a left-handed hitter's advantage at the plate results from facing right-handed pitchers. Today's left-handed batters make more plate appearances against left-handed pitching than their predecessors, because of the prevalence of micro-managed pitching changes.
* * *
What does this all mean? Probably not very much, other than that it's interesting. The waning dominance of left-handed hitters is not occurring quickly enough that it has any practical implications for scouts or GMs or fantasy baseball managers. And it's not as though the advantages enjoyed by left-handed batters have vanished; those players still enjoy an edge, because every player faces more right-handed pitchers than left. But the advantages have diminished, and the gap is slowly closing.