The Details of Our New Prospect Valuation Methodology

Today at FanGraphs, we’re introducing an updated approach to prospect valuation. You can read the announcement here, and also see the new Farm System Rankings for 2026 on The Board. This post is a detailed methodological examination of how we’ve produced our new estimates. It goes over each step of the process in order, and concludes with a sensitivity analysis. If you’re interested in the broad strokes of our new approach, the introductory post will likely suffice. But if you want to see how the sausage is made, read on.
Prospect Classes
We began with Baseball America’s annual Top 100 prospect lists for each year from 2005-2016, plus FanGraphs’ lists for 2017 and 2018. The BA lists serve as a publicly accessible bridge to the current era of FanGraphs prospect writing, and provide a nice through line with Craig Edwards’ earlier research. We took all instances of a prospect being ranked, including duplicates of the same prospect in multiple years. We converted those ordinal rankings into Future Value grades using a two-step process. First, we separated the rankings into pitchers and hitters and created two separate ordinal lists for each year. Second, we adjusted those ordinal rankings between years by a regressed factor based on that class’ major league production. This allowed us to differentiate between classes – without some type of delineation between years, every top overall hitter would receive the same grade, which is contrary to the way we grade prospects.
This method introduces some potential bias. Judging prospects based on how they turned out inherently brings some information from the future into the mix. We decided that this was the best possible way to systematically introduce varying year-over-year quality to an otherwise ordinal-only set of values, and that it also did a good job of replicating the way that grades might have actually been assigned in the past. The top pitching prospect on the 2010 list was Stephen Strasburg. The top pitching prospect on the 2011 list was Julio Teheran. It’s important to differentiate between the likely grade that they would have received. There’s some volatility in relative value assignment at the very top end of the scale based on this methodology, which is addressed in the sensitivity analysis. Read the rest of this entry »



