Rule 2: Age discrimination is not only legal, but mandatory (in minor league baseball, that is … don’t get any ideas … ).
Yes, I am aware of the Age Discrimination in Employment Act, and, needless to say, I am not advocating that anyone ignore its provisions. But …
One of the easiest ways to get over-eager about prospects is to ignore the importance of age level and development, or what is frequently referred to as “age-arc.”
If one is going to spend a lot of time analyzing prospects, one ought to become familiar with the “standard” age-arc:
- Age 19: rookie or short-season
- Age 20: Low-A
- Age 21: High-A
- Age 22: AA
- Age 23: AAA
Clearly, that path is not “set in stone,” and hardly anyone actually takes that route all the way through, but it gives you a good rule of thumb to start with. When a guy is 24 or older and still in A-level ball, then — no matter how good his stats might look — he’s almost certainly not a prospect. And any minor-league stats from guys who are 26 or older don’t really prove anything (which, by the way, does not mean that their stats from age-23 and younger don’t mean anything … see Rule 1).
It is quite common for players of middling talent to get to AA at age 24 or 25, and, after not showing much to that point, start having success at the plate. Often this creates excitement among the fan base that a “sleeper” has arrived. But it’s usually a mirage. The best pitchers at AA are likely to be a couple of years younger, and even slightly older hitters can “figure out” ways to succeed that won’t work against more polished and experienced arms.
On the other hand, when a hitter is younger than the “standard” age-arc, that’s when you take notice. Even if the stats are just at the “hold your own” level, a hitter who is younger than the competition is worth noting.
And a hitter who goes up against an older level and kicks backside (say, Giancarlo — then “Mike” — Stanton hitting .313/.442/.729 in AA at age 20 [yes, the .729 is SLG and not OPS]), then you can set off all the alarm bells, because those are the kind who go on to play in multiple All-Star games and garner MVP votes year after year. Witness: Miguel Cabrera .365/.429/.609 at AA at age 20; Prince Fielder .291/.388/.569 at AAA at age 21.
It was interesting to me to note that the formula for “major league equivalence” does not take the age-arc into account. Stanton’s monster year at AA would have the same “MLE” as a 25-year-old doing the same thing. (Someone correct me if I’m wrong.) But any analysis that treats those seasons as actually equivalent is likely to go wrong.