Question: An American statistician and writer who analyzes baseball cited Leip's Atlas as what?
Related documents: [0]  [DOC] Nathaniel Read Silver (born January 13, 1978) is an American statistician and writer who analyzes baseball (see sabermetrics) and elections (see psephology). He is the editor-in-chief of ESPN's "FiveThirtyEight" and a Special Correspondent for ABC News. Silver first gained public recognition for developing PECOTA, a system for forecasting the performance and career development of Major League Baseball players, which he sold to and then managed for Baseball Prospectus from 2003 to 2009. [END] 
[1]  [DOC] Dave Leip's Atlas of U.S. Presidential Elections is a web site that provides tables, graphs, and maps for presidential (1789–present), senatorial (1990 and onwards), and gubernatorial (1990 and onwards) elections. Data include candidates, parties, popular and electoral vote totals, and voter turnout. County-level data is available for many years, and all data are compiled from official sources. Leip's Atlas has been cited as a "preferred source for election results" by statistician and political pundit Nate Silver. [END] 
Answer: 
"preferred source for election results"
"preferred source for election results"