Just to prep for the offseason, here's an FAQ as to my methodology of evaluating pitching. Note that I'm not saying my way is the absolute only way, but this is to let you know where I'm coming from.
Q: Why don't you include wins and losses in the pitching line?
A: Because they don't really tell me how good the pitcher is. Let me qualify this statement; a pitcher's job every start should be to help the team win that game. So by definition, his goal is to win the game. However, when evaluating a pitcher, you aren't judging him on that season; you are trying to predict how good he's going to be in future seasons. Hopefully that makes sense, but I'll throw out an example to make it a bit clearer.
Here's two pitchers' lines from this season:
215.2 IP, 2.75 ERA, 149 H, 257 SO, 41 BB
193.0 IP, 3.12 ERA, 157 H, 188 SO, 73 BB
The first pitcher is Randy Johnson, he of the 13-13 record. The other pitcher is Roger Clemens, who is 17-4. Johnson's numbers are superior to Clemens' stats in just about every category you can think of...except wins. Randy Johnson is on the worst team in baseball, while Clemens has an outstanding offense behind him.
To hammer my point home, just imagine that Johnson and Clemens switch teams next year, and those teams provide exactly the same run support as this year. Johnson would be the runaway Cy Young winner, and Clemens, well, he'd be a .500 pitcher. I don't include wins and losses for this very reason; a pitcher generally cannot control the offense that hits behind him, but he can control his pitching ability.
Q: What makes some pitchers better than others?
A: Well, let me start by saying that a pitcher's ultimate goal is this: to prevent runs from scoring. Following this thesis, a pitcher is generally good if he allows less runs than most other pitchers. (I know, this is simplistic, but just follow along). Furthermore, a pitcher generally prevents runs by not allowing batters to reach base, so good pitchers allow less hits and walks than most other pitchers. Strikeouts aren't necessary to post a low ERA, but pitchers who rely more on their defense to make outs (ie, groundball pitchers) usually will have more deviation in runs allowed.
Johan Santana 209.0 IP, 2.76 ERA, 144 H, 240 SO, 49 BB
Jake Westbrook 189.2 IP, 3.27 ERA, 178 H, 103 SO, 53 BB
Curt Schilling 204.0 IP, 3.35 ERA, 194 H, 177 SO, 28 BB
Tim Hudson 160.2 IP, 3.36 ERA, 164 H, 90 SO, 38 BB
Brad Radke 204.2 IP, 3.43 ERA, 215 H, 134 SO, 19 BB
Pedro Martinez 199.2 IP, 3.43 ERA, 166 H, 213 SO, 55 BB
Ryan Drese 189.2 IP, 3.75 ERA, 197 H, 88 SO, 53 BB
As you can see, there's more than one way to be a good pitcher. Santana (who should win the AL Cy Young) and Martinez succeed by possessing dominant stuff, Westbrook and Drese succeed by throwing sinkers, and Radke and Schilling's calling cards are impeccable control. But as you can see by the hits allowed column, Westbrook, Radke and Drese are dependent on their defense to catch all those "extra" outs, so having a great defense behind them is almost a necessity when they pitch. It should also be noted that Westbrook has given up 13 unearned runs, so his ERA has been deflated a bit.
Q: So, you look at minor-league numbers the same way, right?
A: Not exactly. Reading minor-league stats leaves out a lot of extenuating factors. For one, I like to qualify a player's numbers by looking at his age and level. In the low minors, a pitcher might put up bad numbers, but he may be working out his mechanics or trying out a new pitch. Also, pitchers who dominate short-season A-ball may not have the stuff to get out AA or AAA hitters. Rating pitching prospects are by rule a crapshoot; trying to project them is even more of a gamble. But if a guy like Adam Miller dominates at two levels at the age of 19, you start to take notice. AA seems to weed out the true prospects from the pretenders, but a future #1 is just an arm injury away from fading away into oblivion. Probably the best way to really see what kind of stuff a minor-league pitcher has is to watch him in person, or at least read an account from a reliable source. Other than that, you just have to try to use the available stats, along with the pitcher's age and make an educated guess.
Let's take the Akron starters, for an example:
Without taking age into account, and looking strictly at the lines, I'd rank them as follows:
1. Andrew Brown
2. Jeremy Guthrie
3. Jake Dittler
4. Dan Denham
5. Francisco Cruceta
6. Fausto Carmona
Now, I'll add their "baseball ages" to this table:
This changes things. Carmona, Denham, and Dittler are 3 years younger than Brown, and 4 years younger than Guthrie. Also, 2004 marked the first year in AA for the three, while this is Guthrie's second stint in Akron. I still like Brown because of his low hit totals, but I like Guthrie a lot less now. Also, Cruceta was promoted to Buffalo and put up these numbers:
83.0 IP, 3.25 ERA, 78 H, 62 SO, 36 BB
Yeah, I don't understand it either. Carmona has also pitched well in a short stint with the Bisons.
So now, taking age into account, as well as other variables, these are my rankings:
1. Andrew Brown
2. Francisco Cruceta
3. Fausto Carmona
4. Jake Dittler
5. Jeremy Guthrie
6. Dan Denham
So that's the method to my madness.