The Numbers Game

New-School Baseball Stats From A to Z

Believe it or not, there was once a time when baseball statistics meant 61 homers, 4192 hits, 56 consecutive games, and 17 beers consumed. But that was before sabremetrics—the science of baseball statistics named after the Society for American Baseball Research, or SABR. Now we can't open up a newspaper or flip on a game without hearing about pitch counts, on-base percentage, and situational hitting. It's changed the way we understand the game, but which numbers really mean something, and what do they mean anyway? With hot-stove league baseball in full swing, and a copy of the recently published The New Bill James Historical Baseball Abstract (hopefully) under your tree, here's a primer on these new-school stats and the people behind them:

Abstract, The Baseball: This was the book that started it all. Originally written by Bill James in the late 1970s, while he was working as a night watchman, the Xeroxed research caught the attention of baseball fans hungry for something smarter than Street & Smith. The Baseball Abstract became an annual bestseller and gave way to even more ambitious projects like the New Historical Baseball Abstract, which rates more than 900 players from all eras. Sabrefact: Norman Mailer was among the Abstract's earliest fans.

Barra, Allen: The Wall Street Journal's By the Numbers columnist and contributor who coined SLOB, which marries the two most important hitting stats—slugging percentage is multiplied by on-base percentage. Sabrefact: In 2001, Barry Bonds posted the second-best SLOB of all time (.444), trailing only Babe Ruth's .451 in 1920.

Illustration by Dusan Petricic

Caught Stealing: The classic hidden stat. Back in the day, a player would get credit for stealing a base. And when he got thrown out, he would get credit for hustling. Problem is, when a player gets nailed at second, it costs the team both a base runner and an out. Which is why, sabremetricians point out, any base stealer who isn't successful at least two-thirds of the time is costing his team runs. Sabrefact: Over the last nine seasons of his career, Ty Cobb stole 127 bases—and was caught 99 times—for a well-below-break-even 56.2 percent.

Denver: All runs are not created equal. At, say, Shea Stadium, three runs can get you a win, but at Denver's Coors Field, three runs is a moderately productive inning. Park Factor attempts to quantify this difference, by comparing the number of runs scored in a stadium to the league average. Sabrefact: After moving to the hitter-friendly Ballpark in Arlington—its park factor of 105 is third best in the AL—Texas Ranger hitters won three MVP awards in four years.

ERA: The most important pitching stat, at least when you're comparing pitchers within an era— say, Mike Mussina (3.49) and Kevin Appier (3.62), as opposed to across eras (Roger Clemens (3.09) and Walter Johnson (2.16). Sabrefact: Lefty Grove led the league in ERA a phenomenal nine times.

Favorite Toy: A way to estimate a player's chances of reaching a goal, by factoring in his distance from the goal, his progress toward the goal (for example, the weighted average of home runs over the past three seasons), and the number of years he's likely to play. Sabrefact: Alex Rodriguez's chance of hitting 756 home runs is roughly 26 percent.

Game Score: James's method of determining a starting pitcher's dominance, by adding points for innings pitched and strikeouts and subtracting them for walks, hits, and errors. Sabrefact: Showing the limitations of this kind of largely descriptive stat, the record for a nine-inning game score is held by Kerry Wood, whose 20-strikeout one-hitter eclipsed every perfect game ever thrown.

Henderson, Rickey: The ultimate sabremetric baseball player. His career batting average is only .280, but he combines the secondary attributes—walks, base running, and power—that don't show up in batting average. And not coincidentally, he owns the career record for runs scored. Sabrefact: Henderson has more secondary bases (4886) than any player except Babe Ruth (5099).

Intentional Walk: Writers like Pete Palmer and John Thorn analyzed the unwritten managerial "book," arguing that intentional walks often blow up in your face, and that sacrifices, while increasing your chances of scoring one run, all but kill your chances of scoring more than one. Sabrefact: On May 29, 1998, Buck Showalter issued an intentional walk to Barry Bonds with the bases loaded and two outs in the ninth, while leading 8-6. The gamble paid off when the next batter, Brent Mayne, lined out to right on a 3-2 count.

James, Bill: Arguably, along with Marvin Miller, the most influential nonplayer of the second half of the last century, James combines cheeky wit (he once described Don Zimmer thusly: "He looks like he was stuffed into his double knits by a taxidermist's apprentice") with iconoclastic arguments (he maintains that the DH actually increases strategy in a game, by removing knee-jerk moves). Sabrefact: The Chicago Tribune once called the Lawrence, Kansas, resident "the Mozart of baseball statisticians."

K: Joe D. never struck out like these guys. So what? Sabremetric research shows that players with high strikeout totals really aren't costing their team very much—what they may give up in "productive outs" they gain back by running up pitch counts and not hitting into double plays. Sabrefact: Bobby Bonds set the single-season strikeout record of 189 in 1970, but in the past two years, five players have fanned 178 times or more.

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