Here is what I could find: "In settling the 1981 Major League Baseball strike, players and owners agreed to a system for ranking major league players for the purpose of determining the compensation to be received by a team when it loses a player through free agency. The settlement to the bargaining impasse included a formula that would be applied to the statistics accumulated by all major league players over the most recent two-year period… the parties agreed that the application of the formula and the consequent production of the rankings would be the responsibility of The Elias Sports Bureau. The system divides players into five different groupings in each of the two leagues-starting pitchers, relief pitchers, catchers, 1B/DH/OF, and 2B/3B/SS. Players are placed into the position at which the player appeared the most over the last two seasons… and then they are rated against one another based upon a variety of statistics. For offensive players, the categories include batting average, on-base percentage, home runs, runs batted in, and fielding percentage… for pitchers, the statistics include appearances, innings pitched, wins, winning percentage, saves, earned run average, WHIP, strikeouts and strikeout-to-walk ratio. Players are then 'compared' to one another based upon these statistics using the agreed-upon formula… they are rated within each of the five grouings, as well as overall (by league). The top 20% of the rankings within the respective groupings are designated as "Type A" free agents and the next 40% are designated "Type B" free agents." Certainly not a complete answer, but it does explain some of the stranger rankings, when you consider the time frame used.