For Chicago Cubs fans not sure about what PECOTA rankings entail, join the club. It is a system from Baseball Prospectus which stands to measure player performance based on a comparison with historical player-seasons. The three elements included in this tracking system are a player’s Major League equivalencies, baseline forecasts, and a career-path adjustment.
These measures, first, predict how a player will produce, based on data of their Minor League stats. Makes sense, right? The second measure of this uses weighted averages and regression to the baseline to project a player’s ultimate talent level. Lastly, it measures how that player’s performance has changed over time.