Brian Hawkes gives us his evaluation of the Sagarin ratings in evaluating fantasy baseball players.
You want to win your fantasy baseball league and you tell me you have never heard of Jeff Sagarin? Well listen up – the Sagarin ratings are part of the holy grail of sabermetrics. Sagarin’s RPG metric for batters calculates the runs per game generated by a particular player if there where an entire lineup made of that individual. For pitchers, the metric he calculates is called Predicted ERA.
The Predicted ERA is calculated by normalizing a pitchers current statistics to a model generated from a dataset of pitching data from 1946-1999. Both, the RPG and Predicted ERA rankings are accepted statistical measurements used by both baseball talent evaluators and gambling odds makers.
The RPG metric is derived using the Markov Chain algorithm which is a rigorous statistical methodology. The final RPG score for batters takes into account runs scored, hits, batting average, runs batted in and stolen bases. The Predicted ERA metric takes into account innings pitched, ERA, Wins, Saves, as well as a few other pitching metrics.
At the end of the day a player’s RPG or Predicted ERA can be used as a direct comparison between players and is an excellent tool for evaluating trades. The Sagrarin ratings can be found in USAToday.
An interesting approach to evaluating trades and comparing players is to combine the Sagarin ratings with the BABIP statistic. The Sagarin rating give a good sense of current player value while BABIP can be used as an indicator of future performance.