How surplus value is determined for prospects ranked in categories. Top 10 (pitchers and hitters), next 10, etc. Explains how teams get a lot of surplus value from the best prospects based on WAR accumulated while they are getting paid during their pre-arbitration years. Worth reading if one is interested. 'By going back through Baseball America’s Top 100 lists from 1994-2005, we can evaluate 12 years worth of players and see how their careers went during their team-controlled years of zero to 6 years of service time. This is when a team gets the most value out of a prospect, as they can pay them $500,000 for the first three years and then depressed salaries through the arbitration process for the next three years.' http://www.thepointofpittsburgh.com/how-much-an-mlb-prospect-is-worth-updated-trade-surplus-values/ (the above link is 2 years old, so surplus values have gone up just a bit, but it's more in-depth explanation than the below link) More updated version: http://www.thepointofpittsburgh.com/mlb-prospect-surplus-values-2016-updated-edition/