One of the most common criticisms of the Brewers organization these days seems to be the notion that the Brewers are particularly incompetent at drafting and developing pitching. This doesn't seem very far-fetched, given that the Brewers rotation is embarrassingly bad year after year (2008 excluded), but I decided to take a look at how the Brewers have done compared to the rest of the NL Central since 2004. Ideally, I would compare them to all of MLB or the NL and over a longer period of time, but this is probably a decent enough sample to begin with. I also looked exclusively at starting pitching (and only a player's innings as a starter if he was both a starter and reliever in one season) since 1) it makes it way easier than looking at relievers too, 2) for the most part bullpens aren't as important as the rotation, and 3) almost every pitcher is drafted as a starter, so it makes sense to only consider starters when evaluating a team's draft/development success.
Defining a starter as any player who had at least three games started in any given season, there have been 351 unique player-seasons in the NL Central since 2004 (and including 2010 through August 6). I compiled the number of games started, the starting runs above replacement (RAR), and the method by which the team acquired that player. For the sake of simplicity, any player who was drafted and developed, signed as an international/amateur free agent and developed, or acquired more than a year before his major league debut was counted as a player drafted and/or developed by that team. This is a pretty generous definition of "developed" for some teams, but it actually favors teams other than the Brewers in the final numbers I calculated. For example, Adam Wainwright is basically the only valuable Cardinals pitcher that qualified as being "drafted and/or developed" by the Cardinals, even though he was a first-round pick by the Braves and spent his Rk/A+/AA seasons in the Braves system (he came to St. Louis as part of the J.D. Drew trade with Atlanta). Any player that had major league experience, whether acquired through trade/free agency/etc., I counted as coming from outside the organization (the lone exception is Randy Wells, who was drafted by the Cubs and went through their minor league system, was given away in the Rule 5 draft to Toronto where he made his major league debut, but was eventually DFA'd and returned to Chicago).
Putting the above data together results in the following rankings:Drafted/Developed Games Started (since 2004)
1 - Pittsburgh Pirates - 601Drafted/Developed Runs Above Replacement (since 2004)
2 - Houston Astros -584
3 - Chicago Cubs - 520
4 - Milwaukee Brewers - 323
5 - St. Louis Cardinals - 293
6 - Cincinnati Reds - 281
1 - Chicago Cubs - 488.6Drafted/Developed RAR/GS
2 - Houston Astros - 482.5
3 - Pittsburgh Pirates - 353.0
4 - Milwaukee Brewers - 329.2
5 - St. Louis Cardinals - 219.3
6 - Cincinnati Reds - 119.6
1 - Milwaukee Brewers - 1.019Externally Acquired Games Started (since 2004)
2 - Chicago Cubs - 0.855
3 - Houston Astros - 0.826
4 - St. Louis Cardinals - 0.748
5 - Pittsburgh Pirates - 0.587
6 - Cincinnati Reds - 0.426
1 - Cincinnati Reds - 795Externally Acquired Runs Above Replacement (since 2004)
2 - St. Louis Cardinals - 770
3 - Milwaukee Brewers - 740
4 - Chicago Cubs - 537
5 - Houston Astros - 469
6 - Pittsburgh Pirates - 466
1 - St. Louis Cardinals - 494.2Externally Acquired RAR/GS
2 - Chicago Cubs - 488.6
3 - Cincinnati Reds - 452.7
4 - Milwaukee Brewers - 398.9
5 - Houston Astros - 321.0
6 - Pittsburgh Pirates - 145.9
1 - Chicago Cubs - 0.910
2 - Houston Astros - 0.684
3 - St. Louis Cardinals - 0.642
4 - Cincinnati Reds - 0.569
5 - Milwaukee Brewers - 0.539
6 - Pittsburgh Pirates - 0.313
In terms of getting results from their drafted/developed pitchers, the Brewers look slightly below average with regards to games started and total runs above replacement, but are (perhaps surprisingly) way in the lead with regards to the quality of the internally-developed pitchers they do start (RAR/GS). One could cynically argue that this is because they've lucked into a couple outstanding talents that even the Brewers organization couldn't mess up (e.g. Sheets and Gallardo), but I think you could also just commend the Brewers for not settling for cheap internal options when those options are barely above replacement level. The Pirates got 601 starts out of their internally developed pitchers, but most of those starts were pretty dreadful.
In my opinion, however, these numbers show that the Brewers are doing just fine drafting and developing pitching. They're fourth in terms of games started/total runs above replacement, but this is probably due to the fact that the Brewers haven't been as gung-ho as a team like the Pirates about filling their rotation with AAA players without much upside, as is reflected in Milwaukee's impressive RAR/GS. The obvious problem appears to be the Brewers' bad luck (or terrible selection) with free agents, as seen in their second-to-last RAR/GS from externally acquired pitchers.
The truth is, even just having Sheets and Gallardo in the last decade is an excellent return for the Brewers. If you look at pitchers who were drafted and developed, and who have had at least two 20+ RAR seasons, the Brewers have Sheets/Gallardo, the Cubs have Prior/Zambrano/Wells, the Cardinals have nobody, the Reds have nobody, the Pirates have Maholm/Duke/Snell, and the Astros have Oswalt/Rodriguez. It's hard to develop superior pitching, and the Brewers have been on par with everyone else in terms of doing that. Most top draft picks don't turn into stars; for every Sheets there a numerous Joneses/Arnetts. In the end, I think it's clearly poor free agent acquisitions that have sunk their rotation year after year, not the organization's track record on drafting/developing pitchers.
Note: One thing this analysis doesn't do is account for the teams' differing ability to add pitching either through the draft or through free agency. The Pirates overall have had much better draft picks than the Brewers and yet ended up with worse internally-developed pitching overall, while teams like the Cardinals/Cubs obviously have a financial edge with regards to bringing in free agents.