<blockquote>To do so, we ran Baseball-Reference.com WAR figures (based on runs allowed) and FanGraphs WAR figures (based on <a href="http://www.fangraphs.com/library/pitching/fip/" target="_blank">Fielding Independent Pitching</a>) against the SP5 list we derived from Retrosheet’s game logs. In each case, we regressed the team’s runs per game differential against the fifth starter’s full-season WAR.</blockquote>
via <a href="http://fivethirtyeight.com/features/even-a-teams-fifth-starting-pitcher-matters-when-trying-to-make-the-playoffs/">Even A Team’s Fifth Starting Pitcher Matters When Trying to Make the Playoffs | FiveThirtyEight</a>.

<a href="http://baseball.brandylion.com/2013/12/24/the-predictive-qualities-of-advanced-pitching-statistics-have-failed-the-orioles/">Ha</a>.