As with all rankings lists, the 2009 TPC top pitching list couldn't include everyone, so I would like to take some time to explain why certain pitchers didn't make the list. For starters, we'll look at Tommy Hanson, the #5 rated prospect in the nation according to Baseball America.
Hanson was considered a very solid prospect heading into 2008, and with a 3.03 ERA at AA in 98 innings in 2008, it looked like he might be ready to make a few starts for the Braves in 2009. Once winter ball rolled around, Hanson headed out to Arizona, where he garnered a lot of attention and the leagues MVP award after striking out 49 batters and allowing just 2 earned runs in 29 innings. Following the conclusion of winter ball, Hanson's stock began to rapidly climb, as several publications gave him the #1 spot among the Braves' prospects, and he was ultimately given the #5 overall spot by Baseball America. As a life long Braves fan, I was excited that so many people believed in Hanson, but there were several reasons why I couldn't fully accept the hype. In fact, after considerable research, I concluded while Hanson had above average talent, the hype had gotten way out of hand, and in scientific terms, a positive feedback system had been created, building hype off of hype. To give everyone a better idea of what led me to this conclusion, I'd like to take some time to discuss a few basic models of analysis that I use.
Last July I wrote a post highlighting some of the comparable pitchers for Hanson, and discussed why I felt the hype was beginning to get out of line with reality. While Hanson's numbers at AA last year looked impressive, once I started comparing them to other pitchers his age, they seemed above average, but not superb.
I ordered the following list of AA stats by fielding independent pitching (FIP), which according to Firstinning.com "considers all things that fielders cannot influence: strikeouts, walks, and home runs. Most pitchers' ability to influence balls in play is relatively weak, so FIP or DIPS are more useful estimates of pitcher's ability than ERA." The official formula for FIP is ((HR*13 + (BB + HBP) *3 - SO * 2) / IP ) + (3.0 to 3.5). The last bit of the equation is league-specific factor that compensates for variations in league talent on a year to year basis.
FIP isn't a fail proof way of judging a pitcher's performance level, but it's fairly accurate, and is especially useful in analyzing minor league pitchers since the varying levels of defensive skill in the minors can wreak havoc on other stats like ERA and WHIP. If I'm looking for a quick summary of a pitcher's performance, I'll usually look at FIP first.
Anyways, according to FIP, Hanson's individual performance level at AA was below a lot of other talented pitchers, many of which pitched at AA at a younger age than Hanson. While several of the pitchers are very talented and were worthy of a top 10 ranking in the minors, others like Sean Gallagher and Wade Davis were generally considered to be in the top 15 or top 20 at best. With an FIP of 3.68, Hanson didn't even beat out Gio Gonzalez, who was ranked as the 97th best prospect in 2009 by Baseball America.
While FIP is a useful stat, it doesn't always tell the whole story. Sometimes I prefer to look strictly at only the stats that a pitcher can directly control, such as strikeouts, walks, and groundball rates (these 3 stats also happen to be the most important indicators of a pitcher's success at the major league level). So, if we take another look at the above list of players and base an analysis strictly off of those 3 stats, where would Hanson fit in? We can immediately put Hughes, Chamberlain, and Gonzalez ahead of Hanson since they did better than him in every category. Once you take age into consideration, Bailey, Billingsley, and Gallardo all performed as well as or better than Hanson at a younger age, so they get ranked ahead of him as well. Brett Cecil had essentially the same strikeout rate, much better control, and a far superior groundball rate, so he too gets ranked ahead of Hanson. That leaves us with just Bowden, Gallagher, and Davis. I can't really argue that any of those 3 are necessarily better than Hanson, but he didn't exceed any of their numbers by a considerable margin, so I also can't make a decent argument to rank him ahead of any of them.
So, if Hanson doesn't look so hot after considering comparable pitchers, FIP, and strictly pitcher controlled factors, statistically speaking there isn't much of a case for him as a current top 10 (or even top 20) talent. The only reason we might be able to justify putting a pitcher with his numbers in the top 20 is if we do so based off of scouting reports. In Hanson's case, scouts rave about his current and future capacity, and that's certainly a good indicator, but the current hype is generally based off of Hanson's performances against high A or AA level hitters, and we've already determined that for his age, Hanson hasn't exactly posted the most superior stats. We also have to keep in mind that scouting reports are very much open to interpretation, and can be written with a personal slant or bias. Scouting reports are also generally based off of a very small sample size, and usually only express data in qualitative terms with very little numerical data to support whatever a scout is assuming about a player's performance. When it comes to a concise scientific analysis of any subject, quantitative data is always preferred over qualitative, and personally, I tend to give statistical data more weight than scouting reports when it comes to minor league prospects. There is no way to accurately and appropriately compensate for all of the variable factors involved in the writing and interpreting of scouting reports. Afterall, other than radar gun readings and some stop watch timings, scouting reports are basically someone's opinion about a certain player, and provide very few hard facts. In most professional circles, theories based off of individual qualitative perception is generally considered bad science. If we accepted as fact everything we think we see without proper analysis, we would all believe that magicians really can fly, and an infinite number of white rabbits can be pulled from a top hat.
But let's say the scouting reports are right, and that they are just as accurate as any statistical data we have at our disposal. From what I've read, Hanson began throwing a slider halfway through the summer, and if you check his stats for July and August, his K% jumped up by about 10%, while his ERA dropped from about 4.00 to below 2.00. I've also read numerous accounts that this spring Hanson has looked very impressive, hitting the high 90's with his fastball, and throwing a slider that compares well to that of John Smoltz. If all of that is 100% accurate, and Hanson is in fact pitching at a level that would allow him at the age of 22 to strike out 30-35% of hitters at AA ball while maintaining the same walk rate and groundball rate, would we be justified in moving him into the top 20 or top 10? The short and honest answer is no. Once you consider his age, those stats still would not be considerably better than the 20 and 21 year olds we looked at above. The same can be said for the scouting reports on Hanson. Once they are interpreted in the appropriate context (age, competition level, comparable players), there are just too many other pitchers the same age or younger who have garnered similar or better reports.
There's just no way to justify naming Hanson one of the top 20 pitchers in the minors based solely off of current statistical and scouting data. We could argue that while he may not be top 20 material at this moment, there might be a chance that we could give him a top 20 spot based off of what we assume he'll do in the future, or in other words, what we believe his ceiling of potential to be. Afterall, if we knew for a fact that Hanson would be a future ace in a year or two, couldn't his current level of performance be overlooked? But here's where we run into a problem. The only resources we have for projecting future performance are stats and scouting reports, both of which can be viewed as data concerning a player's current talent level, or as data concerning a player's future potential. As we've already discussed, the statistical data suggests that Hanson is currently on track to be a good, but not great starter. If we judge him by his comparable players, he could be a solid #2 or #3 starter in a few years, and by his late 20's he could be considered a #1 starter if things go well for him. But after the age of 30, it's very hard to predict what a player will do, as evidenced by the vast array of both stars and average players that have seen their careers take a completely different path once they got past their 20's (see Andruw Jones, Dale Murphy, Jamie Moyer, Sandy Koufax, John Smoltz, etc.). While we'd like to say that Hanson will only get better as he ages, the majority of players see their performance levels decline as they get older, and only a handful are able to continue to play without sustaining some kind of drop off, and even fewer will actually see their performance levels improve. The appropriate thing to do in Hanson's case is to either apply the general trend (his production will decrease from his late 20's to his early to mid-30's), or not speculate about it at all.
So, once again, the statistical data doesn't help Hanson, even if we use it to project his future success. And while some scouts may project him as a future ace, it's really just speculation. Watching a player pitch and calling him a #1 starter doesn't actually make him a #1 starter. He might be given the #1 spot, but unless his performances justify keeping him in that spot, he'll get bumped. And just like we discuessed before, past statistical data doesn't support any type of theory that projects Hanson as a pitcher with #1 starter results anytime soon. If we assume he will actually be a #1 starter in the near future, that assumption will be based solely off of the personal opinion of the so-called expert scouts that have seen him pitch. I don't know about anyone else, but after watching recent events (the economic collapse), my faith in the "experts" is only as strong as the logical and well supported data they provide for their projections, and so far I have not seen any superior scouting reports published on Hanson that were accompanied by a rational and convincing statistical analysis.
Well, this post has gone on much longer than I anticipated, but what I'm really trying to say is that statistically speaking, Hanson is not currently a top 20 pitcher. In statistical terms, he also does not qualify as an elite pitcher when considering his future performance levels. As for scouting reports, current reports are promising, but when taken in context, do not justify a top 20 ranking. The only reason we have to put Hanson in the top 20 is because there are people in major league circles who believe he has the stuff to be a future ace. While it sounds good in theory, it is a very poorly supported assumption, and can be considered personal opinion at best, and speculation at worst. In more critical terms, the only thing suggesting that Hanson will be a future ace is hype, and while hype may sometimes be justified, in this case the only thing supporting the hype is the actual hype itself.
Like I said, I'll have a follow up post coming out soon to address some of the players left off the list, as well as some charts and comparisons to justify my rankings. 
