Numerous pundits have attempted to address the puzzle of why the KC Royals win far more than the sum of their parts suggests they should. For example, Baseball Prospectus’ PECOTA projection system has famously predicted 72 and 76 wins the last two seasons.
Not only did the Kansas City Royals defy Baseball Prospectus’ worst-in-baseball prediction by winning the World Series in 2015, they have exceeded PECOTA’s expectations by a cumulative 21 wins from 2013-15. Indeed, the KC Royals have won more games than any team in baseball (206) over the last two seasons—if you include playoff wins.