This will be short. In honor of Baseball America’s 25 years of ranking prospects, I did an analysis on what have top 100 prospects equated to over the course of that time in terms of regular season wins.
First, 2,500 ranked prospects includes a slew of redundancy from year to year. Chipper Jones, A-Rod, Andruw Jones, and the list can (and does) go on. So this is a raw calculation on that basis. I grouped teams (26) before 1993. With Florida, Colorado, Tamp Bay, and Arizona included, this produced roughly the same R-squared (20%) for a linear analysis. Meaning wins correlated about 20% to the number of prospects a team charted by Baseball America’s yearly top 100. I took franchise wins from 1991-2013 compared it to prospects rankings of Baseball America (1990-2014) during that time:
Here’s the result:
As you can see more prospects generally helped Atlanta – the best team for over a decade – and the Boston Red Sox. ATL’s Chipper Jones, Steve Avery, Andruw Jones, Mark Wohlers, Ryan Klesko, et. al. kept the Tomahawk chop chopping. BOS Nomar Garciaparra, Carl Pavano, Trot Nixon, Hanley Ramirez, Dustin Pedrioa, Jacoby Ellsbury, et. al. challenge the Yankees once the plan came together – with luck too. The Yankees got a bunch of boost from their 1990s prospect: Bernie Williams, Derek Jeter, Andy Pettitte, Alfonso Soriano, but they also did as they usually do – buy up other teams once gifted prospects once they hit FA market. (Jacoby Ellsbury and Brian McCann for recent examples of the aforementioned buying spree of other teams property.)
Teams like the Cubs or Royals were not as lucky, while the Cardinals never got that many on the list, but got wins nonetheless. Is this a sign of a more effective and sound development system in place???
That said, here is some more analysis done – this time by prospect ranking versus WAR from 1990-2013 season of prospects (24 seasons):
As you can see various curves fit better than others. A study by Sky Andrecheck for draft picks through the #500 pick compared to projected WAR compares in many respects. The result: a very similar curve, but a higher exponential drop. (Makes sense. The draft is 6mo.-1-2-3 years before some prospects even rate mention as a top 100, aside from the 1st rounders. C.J. Edwards, anyone?)
…. Here I fit the model using only the first 6 year WAR as the dependent variable (a year of service was defined as 130 AB, 20 games pitched, or 50 innings pitched in a season). As you might suspect, the data follows the same form and shape of the career WAR data. As it turns out, a player’s pre-free agency WAR is almost exactly half of their career WAR. Both models are listed below:
Expected Career WAR = (21.67 + (-11.7 * pitcher) + (6.1 * college)) * selection ^ (-.54)
Expected First 6 Year WAR = (10.9 + (-5.1 * pitcher) + (3.1 * college)) * selection ^ (-.52)
Of use is to see where the linear portion takes over from the exponential, around top prospect 15. From there, the 3 regressions then meet back up at prospect pick 75. So, the top 15 are exponentially better – an inflection point in the analysis at 15. prospects rated #15-75 might get overvalued in comparison to their average WAR results; and the bottom 25 picks maybe undervalued due in part to a prospects first appearance on the list, or the nature of ranking 85 guys behind the 15 considered “can’t miss” prospects.
Andrecheck put this useful table together for the draft:
Anyways, it likely confirms the future if you are an optimistic Cubs fan as BA America has highly rated Javier Baez(#5), Kris Bryant(#8) and the aforementioned C.J. Edwards(#28) on their 2014 top 100 prospects list.