George William “Bill” James (born October 5, 1949, in Holton, Kansas) is a baseball writer, historian, and statistician whose work has been widely influential. Since 1977, James has written more than two dozen books devoted to baseball history and statistics. His approach, which he termed sabermetrics in reference to the Society for American Baseball Research (SABR), scientifically analyzes and studies baseball, often through the use of statistical data, in an attempt to determine why teams win and lose. His Baseball Abstract books in the 1980s are the modern predecessor to websites using sabermetrics such as Baseball Prospectus and Baseball Primer (now Baseball Think Factory).
In 2006, Time named him in the Time 100 as one of the most influential people in the world. He is currently a Senior Advisor on Baseball Operations for the Boston Red Sox. In 2010, Bill James was inducted into the Irish American Baseball Hall of Fame.
Among the statistical innovations attributable to James are:
- Runs Created. A statistic intended to quantify a player’s contribution to runs scored, as well as a team’s expected number of runs scored. Runs created is calculated from other offensive statistics. James’s first version of it was: Runs Created = (Total Bases * (Hits + Walks))/(Plate Appearances). Applied to an entire team or league, the statistic correlates closely to that team’s or league’s actual runs scored. Since James first created the statistic, sabermetricians have refined it to make it more accurate, and it is now used in many different variations.
- Range factor. A statistic that quantifies the defensive contribution of a player, calculated in its simplest form as RF = (Assists + Put Outs)/(Games Played). The statistic is premised on the notion that the total number of outs that a player participates in is more relevant in evaluating his defensive play than the percentage of cleanly handled chances as calculated by the conventional statistic Fielding Percentage.
- Defensive Efficiency Rating. A statistic that shows the percentage of balls in play a defense turns into an out. It is used to help determine a team’s defensive ability. Calculated by: 1 – ((Opp. Hits + Reached on Error – Opp. Home runs) / (Plate appearances – Walks – Strikeouts – HitByPitch – Opp. Home runs)).
- Win Shares. A unifying statistic intended to allow the comparison of players at different positions, as well as players of different eras. Win Shares incorporates a variety of pitching, hitting and fielding statistics. One drawback of Win Shares is the difficulty of computing it.
- Pythagorean Winning Percentage. A statistic explaining the relationship of wins and losses to runs scored and runs allowed. In its simplest form: Pythagorean Winning Percentage equals Runs squared divided by the square of Runs plus the square of Runs Allowed. The statistic correlates closely to a team’s actual winning percentage.
- Game Score is a metric to determine the strength of a pitcher in any particular baseball game.
- Major League Equivalency. A metric that uses minor league statistics to predict how a player is likely to perform at the major league level.
- The Brock2 System. A system for projecting a player’s performance over the remainder of his career based on past performance and the aging process.
- Similarity scores. Scoring a player’s statistical similarity to other players, providing a frame of reference for players of the distant past. Examples: Lou Gehrig comparable to Don Mattingly; Joe Jackson to Tony Oliva.
- Secondary average. A statistic that attempts to measure a player’s contribution to an offense in ways not reflected in batting average. The formula is (Extra bases on hits+Walks+Stolen Bases)/At bats. Secondary averages tend to be similar to batting averages, but can vary widely, from less than .100 to more than .500 in extreme cases. Extra bases on hits is calculated with the formula (Doubles)+(Triplesx2)+(Homerunsx3) or more easily, (Total Bases)-(Hits).
- Power/Speed Number. A statistic that attempts to consolidate the various “clubs” of players with impressive numbers of both home runs and stolen bases (e.g., the “30/30″ club (Bobby Bonds was well known for being a member), the “40/40″ club (José Canseco was the first to perform this feat), and even the “25/65″ club (Joe Morgan in the ’70s)). The formula: (2x(Home Runs)x(Stolen Bases))/(Home Runs + Stolen Bases).
- Approximate Value. A system of cutoffs designed to estimate the value a player contributed to various category groups (including his team) to study broad questions such as “how do players age over time”.
Although James may be best known as an inventor of statistical tools, he has often written on the limitations of statistics and urged humility concerning their place amidst other kinds of information about baseball. To James, context is paramount: he was among the first to emphasize the importance of adjusting traditional statistics for park factors and to stress the role of luck in a pitcher’s win-loss record. Many of his statistical innovations are arguably less important than the underlying ideas. When he introduced the notion of secondary average, it was as a vehicle for the then-counterintuitive concept that batting average represents only a fraction of a player’s offensive contribution. (The runs-created statistic plays a similar role vis-à-vis the traditional RBI.) Some of his contributions to the language of baseball, like the idea of the “defensive spectrum”, border on being entirely non-statistical.
In an essay published in the 1984 Abstract, James vented his frustration about Major League Baseball’s refusal to publish play-by-play accounts of every game. James proposed the creation of Project Scoresheet, a network of fans that would work together to collect and distribute this information.
While the resulting non-profit organization never functioned smoothly, it worked well enough to collect accounts of every game from 1984 through 1991. James’s publisher agreed to distribute two annuals of essays and data – the 1987 and 1988 editions of Bill James Presents The Great American Baseball Statbook (though only the first of these featured writing by James).
The organization was eventually disbanded, but many of its members went on to form for-profit companies with similar goals and structure. STATS, Inc., the company James joined, provided data and analysis to every major media outlet before being acquired by Fox Sports in 2001.
Acceptance in mainstream baseball
Oakland Athletics general manager Billy Beane began applying sabermetric principles to running his low-budget team in the late 1990s, to notable effect, as chronicled in Michael Lewis’ book Moneyball).
In 2003, James was hired by a former reader, John Henry, the new owner of the Boston Red Sox.
One point of controversy was in handling the relief pitching of the Red Sox. James had previously published analysis of the use of the closer in baseball, and had concluded that the traditional use of the closer both overrated the abilities of that individual, and used him in suboptimal circumstances. He wrote that it is “far better to use your relief ace when the score is tied, even if that is the seventh inning, than in the ninth inning with a lead of two or more runs.” The Red Sox in 2003 staffed their bullpen with several marginally talented relievers. Red Sox manager Grady Little was never fully comfortable with the setup, and designated unofficial closers and reshuffled roles after a bad outing. When Boston lost a number of games due to bullpen failures, Little reverted to a traditional closer approach and moved Byung-Hyun Kim from being a starting pitcher to a closer. The Red Sox did not follow James’ idea of a bullpen with no closer, but with consistent overall talent that would allow the responsibilities to be shared. Red Sox reliever Alan Embree thought the plan could have worked if the bullpen had not suffered injuries. During the 2004 regular season Keith Foulke was used primarily as a closer in the conventional model; however, Foulke’s usage in the 2004 postseason was along the lines of a relief ace with multiple inning appearances at pivotal times of the game. Houston Astros manager Phil Garner also employed a relief ace model with his use of Brad Lidge in the 2004 postseason.
James is still (2010) employed by the Red Sox, having published several new sabermetric books during his tenure (see Bibliography, below). Indeed, although James is typically tight-lipped about his activities on behalf of the Red Sox, he is credited with advocating some of the moves that led to the team’s first World Series championship in 86 years, including the signing of non-tendered free agent David Ortiz, the trade for Mark Bellhorn, and the team’s increased emphasis on on-base percentage. During his time with the Red Sox, Bill James has received two World Series rings for the team’s 2004 and 2007 victories.
Sabermetrician Martin Bernstein points out on Baseball Prospectus that knowledge is pointless without application. Following the aforementioned Red Sox and Billy Beane’s Oakland Athletics, most major league teams today use sabermetrics and statistic tracking. But although sabermetrics is mostly accepted within baseball, Bernstein says that there is another frontier – the average fan still does not readily use or accept sabermetrics. Beane is such a renowned figure not for his actual innovations in specific statistics or ideas, but for his open-mindedness and application of knowledge that led other’s inside baseball to apply sabermetrics as well. Bernstein concludes that the next most important innovation in the field will be in getting fans to accept and use sabermetic knowledge, and that this goal should be the main focus of sabermetricians until it is accomplished.
The Mind of Bill James, a biography-cum-chronicle of James’s works was published in the spring of 2006. How Bill James Changed Our View of the Game of Baseball was published in February 2007. He was profiled on 60 Minutes on March 30, 2008, in his role as a sabermetric pioneer and Red Sox advisor.