OK, as I've posted here multiple times before, I'm pretty ignorant about stats, etc. but love coming here to learn about player evaluation tools.

So... Here's my question. Niekro is doing good at AAA, yet nobody expects him to excel at the major league level. Todd Linden was putting up Manny Ramirez type numbers in Fresno, but struck out 8 out of every 10 ABs in the majors. I was so thoroughly disappointed by these two, because I thought they could become productive major leaguers, or at least good bench players. But instead they just did a whole lot of sucking.

What I'm wondering is, is it common for minor leaguer position players to do so well in AAA and then totally blow in the majors? I know it happens, but does it happen a lot? And, if it's the case that position players are tough to project, is there anything that can tell you how well a minor league guy will hit in the majors? I mean, Jesus, if Todd didn't seem like a sure thing based on his AAA numbers then I want to know what one looks for.

The discussion I want to get going is this: We all know that no prospect is a sure thing. But once a guy has had prolonged success in the high minors, are there any tools to separate the Todd Lindens from the David Wrights? Partly the answer must be scouting. Todd had crazy success in the minors b/c the pitchers weren't good enough to exploit the holes in his swing. That changed in the majors. But beyond that, are there any stats to look for?

I just don't want to get my hopes up anymore...