 Silver further developed PECOTA and wrote a weekly column under the heading "Lies, Damned Lies".He applied sabermetric techniques to a broad range of topics including forecasting the performance of individual players, the economics of baseball, metrics for the valuation of players, and developing an Elo rating system for Major League baseball.Between 2003 and 2009, Silver co-authored the "Baseball Prospectus" annual book of Major League Baseball forecasts, as well as other books, including "Mind Game