We Were Prospects Once, and Young

The Blessings of Youth

My good friend Rany Jazayerli has a pair of intriguing articles up at Baseball Prospectus, looking at the importance of youth in draft picks. Links: Part One and Part Two.

His basic conclusion is that, for hitters anyway, age-relative-to-competition is even more important than we previously believed, at least when looking at the projected value of draft picks.

The basic principle is well-known, although as Rany says, the effect was stronger than anticipated. His conclusion from Part One of the article:

This is, all modesty aside, quite possibly the most impressive and significant finding of my career. When it comes to the drafting of high school hitters, even slight differences in age matter. At least when it comes to high school hitters, young draft picks are a MASSIVE market inefficiency.

In The 1985 Bill James Abstract, James published the results of his study which showed that "The rate of return on players drafted out of college is essentially twice that of high school players." That is considered to be one of James' most important findings, and in fact it was more than a little surprising when, in 2005, I found that the advantage for college players had almost disappeared over the years.

Based on the data above, the advantage the youngest high school hitters in a draft class have on the oldest high school hitters is just as great as the advantage college hitters once enjoyed. And this advantage does not appear to be diminishing over time.

A few months ago, in a discussion about the fact that Bubba Starling was a little older than some other players in the high school class, someone asked me what I thought about the issue. I said that it was obviously an important factor, but that too much could be made of it, and that I didn't think a player being a few months older made that much of a difference all things considered. Perhaps it makes more of a difference than I thought, although I do think it is important to remember that players need to be judged on a case-by-case basis.

What do you guys think about this?