Nate Silver

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Nathaniel Read Silver (b. 1978, East Lansing, Michigan; now residing in Chicago, Illinois) is Managing Partner of Baseball Prospectus. He is best known for inventing PECOTA, a system for forecasting the performance and career development of Major League Baseball players. In 2008 he began to publish analyses and predictions of U.S. presidential primaries and the general election, initially under the pseudonym "Poblano" and later under his own name.^[1]

Contents 1 Early Background 2 Career 3 PECOTA, QERA, and the "Secret Sauce" 3.1 PECOTA 3.2 QERA 3.3 "Secret Sauce" 4 Political analysis 5 Other interests 6 Notes 7 References

[edit] Early Background

According to journalist William Hageman, "Silver caught the baseball bug when he was 6, growing up in East Lansing, Mich. It was 1984, the year the Detroit Tigers won the World Series. The Tigers became his team and baseball his sport. And if there's anything that goes hand in glove with baseball, it's numbers, another of Silver's childhood interests. ("It's always more interesting to apply it to batting averages than algebra class.")"^[2]

As a student at East Lansing High School, in 1996 Silver won first place in the State of Michigan in the 49th annual John S. Knight Scholarship Contest for senior high school debaters.^[3]

Silver earned his journalism chops writing and editing The Portrait, East Lansing High School's student newspaper from 1993-1996.

In 2000, Silver graduated with Honors from the University of Chicago, where he studied economics. He spent his junior year at the London School of Economics.

[edit] Career

After graduating from college, Silver worked for three and a half years as an economic consultant with KPMG. Silver continued to nurture his life-long interest in baseball and statistics, however, and on the side he began to work on his system for projecting player performance and careers.

Silver joined the Baseball Prospectus staff in 2004 after selling the PECOTA projection system to BP. Since then, he has maintained and further developed PECOTA as well as written a weekly column for BaseballProspectus.com under the heading "Lies, Damned Lies". In this column he applies sabermetric techniques to a broad range of topics in baseball research -- including forecasting the performance of individual players, the economics of baseball, metrics for the valuation of players, developing an Elo rating system for Major League baseball,^[4] and many other topics.

Since 2003 he has been a co-author of the Baseball Prospectus (ISBN 0-7611-3995-8) annual book of Major League Baseball analysis and forecasts as well as a co-author of other books published by Baseball Prospectus, including Mind Game: How the Boston Red Sox Got Smart, Won a World Series, and Created a New Blueprint for Winning (New York: Workman Publishers, 2005) (ISBN 0-7611-4018-2), Baseball Between the Numbers (New York: Basic Books, 2006) (ISBN 0-4650-0596-9), and It Ain't Over 'til It's Over: The Baseball Prospectus Pennant Race Book (New York: Basic Books, 2007) (ISBN 0-4650-0284-6).

He has been an occasional contributor of articles about baseball to ESPN.com, Sports Illustrated, Slate, the New York Sun and the New York Times.

In 2007, while still working for Baseball Prospectus, he began to write about politics, specifically the 2008 U.S. Presidential race. Until the end of May 2008, all of these writings were under the pseudonym "Poblano" and appeared on Daily Kos or on his blog FiveThirtyEight. Beginning in June he began to publish political analysis under his own name, including in his blog, newspapers, and the on-line The Guardian and The New Republic.

[edit] PECOTA, QERA, and the "Secret Sauce"

Silver uses a wide variety of research methods and statistical tools in his writings about baseball. However, he has developed three tools that are identified with his name.

[edit] PECOTA

Main article: PECOTA

PECOTA is a statistical system that projects the future performance of hitters and pitchers. It is designed primarily for two uses: fans interested in fantasy baseball, and professionals in the baseball business interested in predicting the performance and valuation of major league players. Unlike most other such projection systems, PECOTA relies on matching a given current player to a set of "comparable" players whose past performance can serve as a guide to how the given current player is likely to perform in the future. Unlike most other such systems, PECOTA also calculates a range of probable performance levels rather than a single predicted value on a given measure such as earned run average or batting average.

PECOTA projections were first published by Baseball Prospectus in the 2003 edition of its annual book as well as online by BaseballProspectus.com. The formulas have been updated steadily since then.

[edit] QERA

Because of the dependence of earned run average statistics on factors over which a pitcher may have little control, sabermetricians have developed several defense independent pitching statistics, including Defense-Independent ERA. One that Silver has created for quick calculations that do not require detailed adjustments for the park or era in which a pitcher is performing is the "QuikERA" or QERA. It may be useful for early- or mid-season assessments of a pitcher's performance, since it attempts reduce the effect of luck in summarizing a pitcher's ERA.^[5] Silver explains,

I call this toy QuikERA (QERA), which estimates what a pitcher's ERA should be based solely on his strikeout rate, walk rate, and GB/FB ratio. These three components--K rate, BB rate, GB/FB--stabilize very quickly, and they have the strongest predictive relationship with a pitcher’s ERA going forward. What’s more, they are not very dependent on park effects, allowing us to make reasonable comparisons of pitchers across different teams.

The formula for QERA is as follows: QERA =(2.69 + K%*(-3.4) + BB%*3.88 + GB%*(-0.66))².

Note that everything ends up expressed in terms of percentages: strikeouts per opponent plate appearance, walks per opponent plate appearance, and groundballs as a percentage of all balls hit into play.^[6]

[edit] "Secret Sauce"

Silver has also developed a formula, which he calls "Secret Sauce," to predict whether Major League teams are likely to be successful in the playoffs if they somehow manage to reach them.^[7] This formula comes out of research that he initially conducted and published with Dayn Perry.^[8] Although during the regular season having an excellent offense above all else may get a team to the playoffs, once in the playoffs a team's success depends much more on strong defense, including pitching.

The "secret sauce" formula includes

"[three] key ingredients that strongly correlate with postseason success: a team's [pitchers'] strikeout rate, or Equivalent K/9 (EqK9), adjusted for a team's league and ballpark; its quality of defense, or Fielding Runs Above Average (FRAA), an estimate of the runs a defense has saved or cost its pitchers relative to the league average; and its strength of closer, or Win Expectation Above Replacement (WXRL), which measures the wins the closer has saved versus what a replacement-level alternative would have done.^[9] In other words, teams that prevent the ball from going into play, catch it when it does and preserve late-inning leads are likely to excel in the playoffs."^[10]

[edit] Political analysis

Beginning in October 2007, Silver began to publish a diary under the pseudonym "Poblano" on the progressive political blog Daily Kos. Silver set out to analyze quantitative aspects of the political game in a manner that would enlighten a broader audience. His forecasts of the primary elections drew a lot of attention, including being cited by New York Times Op-Ed columnist William Kristol.^[11]

In March 2008, he established his own blog FiveThirtyEight.com, in which he developed a system for tracking and forecasting the outcome of the 2008 U.S. presidential election. At the same time, he continued making forecasts of the 2008 Democratic primary elections. That several of his forecasts based on demographic analysis proved to be substantially more accurate than those of the professional pollsters gained visibility and professional credibility for "Poblano."^[12] As a result, his blog generated a growing following among political junkies, increasing numbers of whom contributed constructive and critical comments on his columns. In addition, he posted the results there^[13] of some pro bono work that he provided to Progress Illinois estimating the possible impact of increased voting by African Americans, Latinos, and young people in the November election on Obama's chances of success – something that was dubbed "The Poblano Effect."^[14]

On May 30, 2008, Poblano revealed his identity to his FiveThirtyEight.com readers with the following statement:

"There are certain pleasures in writing anonymously. Particularly in the political world, where there is a whole mythology associated with anonymity -- think Deep Throat or Primary Colors or Atrios. But I'm fortunate enough to have been granted the opportunity to develop some relationships with larger outlets (you should see these coming to fruition very soon). And it just ain't very professional to keep referring to yourself as a chili pepper.

My real name is Nate Silver and my principal occupation has been as a writer, analyst and partner at a sports media company called Baseball Prospectus. What we do over there and what I'm doing over here are really quite similar. Both baseball and politics are data-driven industries. But a lot of the time, that data might be used badly. In baseball, that may mean looking at a statistic like batting average when things like on-base percentage and slugging percentage are far more correlated with winning ballgames. In politics, that might mean cherry-picking a certain polling result or weaving together a narrative that isn't supported by the demographic evidence."^[15]

On June 1, Silver published a two-page Op-Ed article in the New York Post outlining the rationale underlying his focus on the statistical aspects of politics.

"My fulltime occupation has been as a writer and analyst for a sports media company called Baseball Prospectus. In baseball, statistics are meaningless without context; hitting 30 home runs in the 1930s is a lot different than hitting 30 today. There is a whole industry in baseball dedicated to the proper understanding and interpretation of statistics. In polling and politics, there is nearly as much data as there is for first basemen. In this year's Democratic primaries, there were statistics for every gender, race, age, occupation and geography - reasons why Clinton won older women, or Obama took college students. But the understanding has lagged behind. Polls are cherry-picked based on their brand name or shock value rather than their track record of accuracy. Demographic variables are misrepresented or misunderstood. (Barack Obama, for instance, is reputed to have problems with white working-class voters, when in fact these issues appear to be more dictated by geography - he has major problems among these voters in Kentucky and West Virginia, but did just fine with them in Wisconsin and Oregon)".^[16]

Silver's self-unmasking brought him a lot of publicity, including articles about him in the Wall Street Journal^[17] and Newsweek.^[18] In early June he began to cross-post his daily "Today's Polls" updates on "The Plank" in The New Republic.^[19]

[edit] Other interests

Silver has long been interested in fantasy baseball, especially Scoresheet Baseball. While in college he served as an expert on Scoresheet Baseball for BaseballHQ.

In his spare time, Silver uses his analytical approach at the poker table where he plays semi-professionally.^[20] In his blog, "The Burrito Bracket", he applies a one-and-done approach to assessing the quality of the taquerias in his Wicker Park neighborhood in Chicago. He is not related to his fellow Chicagoan and namesake Nate Silver who at 5' 8", 150 lbs., played quarterback for the Notre Dame football team in 1902-1905.^[21]

[edit] Notes

[edit] References

• Rich Lederer, "An Unfiltered Interview with Nate Silver" Baseball Analysts, February 12, 2007.
• Steven D. Levitt, "Freakonomics: More on Roger Clemens" New York Times, February 18, 2008].
• Michael Miner, "The Algorithm Method: Hot Type’s coveted Golden BAT award goes to a computer program", Chicago Reader, March 27, 2008].
• Tim Murphy, "Timeout with Nate Silver: BP’s VP illuminates the sport’s fuzzy numbers", Chicago Maroon, May 11, 2007].
• Alan Schwarz, "Numbers Suggest Mets Are Gambling on Zambrano" New York Times, August 22, 2004.
• Alan Schwarz, "Predicting Futures in Baseball, and the Downside of Damon", New York Times, November 13, 2005.
• Childs Walker, "Baseball Prospectus Makes Predicting Future Thing of Past," Baltimore Sun, February 21, 2006.