Scouting. The same type of prospect reports that we use to find make our judgements about these prospects. The same reports that told all of us that Lincecum had nasty stuff. I doubt you have seen Lincecum play very often, so I'm guessing you get most of your information about the guy from what you read about him rather than your own scouting.
Outside of a few exceptions, none of us have seen these players play, so like me, I'm guessing just about everyone here relies on prospect reports from places like baseball america.
Projections cannot simply be seen from statistics. There is a lot that can be seen by just watching the players, and that is a better way of determining upside than a couple hundred at-bats in rookie ball. Everything I have read on Stubbs basically writes the same strory:
- Great Fielder
- Decent patience
- Good power potential
- Poor contact skills
- Top end speed
- Very raw
It's clear to everyone that Stubbs is a long ways away from contributing in the majors. It's the potential we all disagree on. Now I'm not going to proclaim myself an expert in regards to Stubbs (or any Reds prospect for that matter) as I haven't seen any of them play. However, I do understand that players develop at different rates, and for the most part scouting reports give a better indication of determining a player's upside than a player's first jump into rookie ball. Potential can be easily scouted. Looking at a player's build, athleticism can lead to the conclusion that things like power and contact can be developed even if those skills have not been translated onto the baseball field yet.