Let me begin this Fanpost by making an admission: I was wrong.
That's tough for me to say, because I like to be right, and I don't like to admit being wrong. I doubt anyone does. I will put a in great deal of effort to prove that I am right, at times. This is one of those times. It backfired.
But being the consummate professional, I decided that I should share the results of my effort and admit my wrongness, rather than bury them and hope no one else is OCD enough to follow me down the rabbit hole. So, what follows is a statistical analysis of MLB drafting from 2000-2008, encompassing JZ's tenure running the draft in Milwaukee.
First, some caveats and explanations. The data I used ends at 2008 because in 2009, BR started categorizing their OFs by region (LF/CF/RF/OF) but did not update their search tool to match. So it would have been WAY more work to pull those numbers. Additionally, the closer you get to the present, the more variability you get in results, so giving a 5 year cushion isn't a bad thing in any case. Data may also include some "doubles", as I had no way of removing guys who were drafted more than once. However, this applied to both sets of data and should be balanced out by the fact that being drafted twice shouldn't actually change your odds of success. It's also a small-ish number of guys. Lastly, there is no way for me to account for "player development," so this is purely based on drafting. There may also by a very few players missing if they were oddly categorized by BR, but no one of substance.
The idea behind my research was to compare Zduriencik's draft results with those of the league in general, to determine if he is indeed a superior drafter of talent. My working hypothesis was that he is not. My conclusion, well, you'll see. To the numbers!
From 2000-2008, there were approximately 13350 players drafted in the June amateur draft. Of those players, 1791 have played in the Major Leagues. This is 13.4% of draftees. Additionally, these 1791 players have accumulated (as of August 29, 2013) 4786.8 bWAR. This works out to 15.96 WAR per team per draft, 0.36 WAR per Draftee, and 2.67 WAR per Major Leaguer. Furthermore, 298 of these players have accumulated at least 5 bWAR in their careers - guys who could be reasonably termed "successful" thus far. That's 2.23% of Draftees and 16.64% of Major Leaguers. So that's our baseline.
In that same timeframe, JZ's Brewers drafted 440 players, of which 55 made it to MLB. That's 12.5%, about 0.9% lower than average. So they should have found another 4-5 pros - one mark against Z.
That's where the bad marks end. Jack's 55 pros have managed to amass 204.8 bWAR, for 20.48 WAR per draft - outpacing the league by 4.52 (a 28.3% edge). Each Draftee has been worth .47 WAR, outpacing the league by about 30%. Each Major Leaguer has been worth 3.72 WAR, beating the average by almost 40%. 16 of his 55 pros have reached 5+ WAR, for 3.64% of Draftees and 29.09% of Major Leaguers.
Data in chart form:
So, I'm forced to eat a little crow on this front. While he hasn't been spectacular at finding a volume of Major League talent, what he has found has outpaced the league by a large margin. I'm forced to conclude that JZ can draft. While luck may or may not be the driving factor behind all Major League talent evaluation, JZ and Co. in Milwaukee can proudly point to their record and know that, luck or skill, they beat the pants off of most everybody else.
While I still believe he needs to go, as I don't feel he has any ability to skillfully manipulate a Major League roster, JZs draft record is more than good enough for another rebuilding team to take a chance with him at the GM. Really, though, a high-end team should offer him serious money to be their Draft Director and he should stick to what he's good at. Because he's pretty darn good at drafting.
PS - If anyone wants the underlying data for this, or some of the other things I've gleaned from it (draft SS and 3B, don't draft C or OF,) or has any questions, let me know in the comments and I'll do my best to reply.