Random Win % - Part 5: Specifics of the RW% approach

This is the fifth of a series of posts about the next evolution in valuing players for fantasy football. Just as value based drafting (VBD) corrected many of the errors in drafting by pure points scored, Random Win % (RW%) corrects many areas which VBD does not address easily. The end result - better drafts, more wins, and more championships!

In part 4, I outlined the basic approach to determine random win % for a given player. Let's flesh that out a bit and detail how to calculate the RW% for a given player:

1. Gather the projected stats for the week for every player.
2. Using the league's scoring requirements, determine the projected score for each player.
3. Using the league's starting lineup requirements, determine the pool of potential starters at each position.
4. Using the pool of potential starters, create enough fantasy teams to create a meaningful sample (I recommend 200,000, which will get you within 1% of the true RW% with high confidence).
5. Pair the 200,000 teams into 100,000 games of Team A vs Team B.
6. For each game, for each unique position, calculate the number of projected points the rest of Team A scores and subtract this total from Team B's total (Team B total - total of other Team A players).
7. For each potential starter, count up how many games that player's projected point total is more than the calculation in step 6 for his position. Note: you can also think of this as the number of games in which Team A would have outscored Team B if that player was in Team A's lineup.
8. Divide the number of games won (from step 7) by the total number of games to calculate the players RW%.

Our end result is that regardless of league size, scoring system, bench size, or position requirements, we can assign every player at any position a score from 0% to 100%. It's a bit of work, but in my next post, I will review the benefits we get for our trouble.