With the Pirates' success over the first half of the season, it has been easy to overlook the fact that their farm system is as strong as it has been in recent memory.
Despite their inability to agree to terms with No. 8 overall pick Mark Appel, the Bucs boast several high-end talents throughout the organization. This talent is supported by an increasing level of depth throughout the minor leagues.
The prospect ranking below takes into account performance through the All-Star break and includes signed draft picks (had the Pirates signed Appel I would have ranked him fourth). I will update the ranking again at the end of the season.
1. Gerrit Cole (RHP, Altoona)
Most have considered Cole the Pirates' top prospect since the team drafted him No. 1 overall in the 2011 draft. The UCLA right-hander can top 100 on the radar gun and backs up his fastball with a plus slider and changeup.
While Cole has not dominated this year, he has performed consistently well, striking out over a batter an inning. He was recently promoted to Altoona, where his peripherals have remained strong.
In an organization with multiple potential No. 1 starters, Cole remains the top prospect by a hair. He is the most polished and may be ready to join the Pirates as early as June 2013.
2. Jameson Taillon (RHP, Bradenton)
The 2010 No. 2 overall pick would be most organizations' top prospect, and he makes a fantastic 1B for the Pirates. The hard-throwing Texan's arsenal is centered around two elite pitches: a 97-98 MPH fastball and a 12-to-6 curveball.
As FanGraphs' Kiley McDaniel notes, Taillon has not been consistent this year. Even following a recent slump, his numbers remain above-average, yet his strikeout rate has fallen off as he has struggled to locate his fastball and generate a sharp break on his curveball.
Yet Taillon, who has already thrown only one less inning than he did last season, remains a considerably talented pitcher. He is a potential future ace and would slot in nicely behind Cole in the Bucs' rotation in 2014.
3. Luis Heredia (RHP, State College)
Heredia has as much talent as either Cole or Taillon, but his development is far behind that of the other two pitchers.
Of course, he's only 17 years old. And even at 17 years old, pitching to college juniors and seniors, Heredia is putting up strong early numbers. While the process is more important than the results this year, it doesn't hurt to see him succeeding either.
I have Heredia ranked higher than most other people do, as his ceiling his unmatched. There is a lot that can go wrong between State College and Pittsburgh, but pitching prospects with Heredia's potential are rare. Just because he is not Cole or Taillon yet does not mean Heredia should be taken for granted.
Would you include Luis Heredia in a trade for Justin Upton?
4. Starling Marte (OF, Indianapolis)
The Pirates' top hitting prospect remains another relatively polarizing player. Marte's strengths—contact, speed, defense—are obvious, but at times his weaknesses—strike zone control and overall approach at the plate—can be just as glaring.
Marte has made strides in Triple-A this season, improving his walk and power statistics, but he is still striking out over 20 percent of the time, a high number for a hitter who expected to make a living primarily by hitting for average.
Marte will likely join the Pirates' outfield within a month, and he clearly has the skill set to be an above-average regular. But the flaws in his game may hold him back from ever becoming a star.
5. Josh Bell (OF, West Virginia)
The Pirates have not seen much of Bell since they paid him a substantial bonus to forgo his commitment to the University of Texas. The outfielder has not yet returned to the field following his knee surgery in April.
It is a shame to lose months of development, but Bell has yet to turn 20. He has the most power of any hitter in the Pirates' organization other than Pedro Alvarez, so he will remain an important part of the Bucs' future for a while.
It will be at least 2-3 years before Bell is ready to don the black and gold, but he is the closest thing the Pirates have to a true middle-of-the-order bat in the minors.
6. Alen Hanson (SS, West Virginia)
Hanson has been the breakout star of the Pirates' farm system this year. The 150-pound middle infielder has followed up two years of excellent contact hitting with a power surge, belting 15 home runs already this season.
A shortstop who slugs .575 and steals 20-30 bases is a rather valuable commodity, though it remains to be seen if Hanson can stay at the position. His bat looks like it would play just fine at second base, however, or at any position if this year is any indication.
Yet Hanson also has considerable room to grow, as he hasn't even turned 20. He remains a bit lower on this list due to a lack of pedigree compared to some of the top performers above him, but he has as much upside as any hitter in the organization not named Andrew McCutchen.
7. Jeff Locke (LHP, Indianapolis)
The Indianapolis left-handers represent the near-opposite type of prospect from Hanson. They do not have star potential, yet they have performed consistently for several years and should become solid No. 3 or No. 4 starters. They are a tier below a player like Hanson as the upside simply isn't there, but they are valuable commodities nonetheless.
Who should be the Pirates' top hitting prospect?
Locke is the best of the three, with better peripheral statistics than Rudy Owens. A 3.40 FIP in Triple-A is nothing to sneeze at.
I believe Locke is a better pitcher than Kevin Correia right now. There's a good chance either Locke or Owens will be asked to help the Pirates down the stretch this year, and I hope Locke gets the first look.
8. Robbie Grossman (OF, Altoona)
Grossman is a sabermetrician's delight, posting excellent walk rates throughout his minor league career. Yet scouts have often questioned whether he can hit consistently and with enough power to be an everyday corner outfielder.
Grossman was on his way to answering those questions last fall, posting a .1097 OPS in the Arizona Fall League before breaking his hammate bone. The injury is known to sap power for the better part of a year, so it his hard to properly evaluate his 2012 performance.
Yet he has done enough to maintain his solid prospect status, compiling a stellar on-base percentage (.367 this year) once again. He is only 22 years old and remains an important part of the Pirates' outfield depth.
9. Kyle McPherson (RHP, Altoona)
McPherson is another player who has put together several strong seasons in the Pirates' organization. If not for a shoulder injury that sidelined him for the first half of the year, McPherson may have been next in line for a spot in the Pittsburgh rotation.
A shoulder injury is always a concern, but it's a good sign that McPherson has pitched well in his five starts since returning to Altoona this season.
At his best, McPherson combines the excellent command of a pitcher like Rudy Owens with a superior ability to miss bats. McPherson has a higher ceiling than any of the pitchers currently in Indianapolis.
10. Gregory Polanco (OF, West Virginia)
Polanco has followed in Alen Hanson's footsteps this season, flashing brilliant power and speed during a breakout year in West Virginia.
While Polanco is only a year older than Hanson, he is still only 20, and he has as much star potential as the West Virginia shortstop.
Yet Polanco places a more common position than Hanson and he did not have nearly as strong of a track record as Hanson did coming into the 2012 season. Polanco still has more to prove.
11. Rudy Owens (LHP, Indianapolis)
Prior to this season, Owens was ahead of Locke developmentally, but he seems to have plateaued a bit in Triple-A.
In two seasons with Indianapolis, Owens has averaged roughly six K/9. It's hard to excel in the majors without missing bats, so Owens seems like a back-of-the-rotation arm at best.
Owens is another potential call-up this season, but the Pirates might be better off trading him if his value is indeed higher than Locke's.
12. Bryan Morris (RHP, Indianapolis)
Once considered a potential No. 2 starter, Morris has re-invented himself as a late inning reliever. His performance has improved substantially in this role, as Morris is now striking out more than a batter an inning with better control numbers.
Morris was a Pirate for a day this year, though he did not appear in a game for the team. He will certainly be called up in September if not earlier.
The Pirate were expecting more than a late-inning reliever when they acquired Morris as part of a prospect package for Jason Bay, but his emergence will aid Neal Huntington's annual low-cost bullpen construction during the next few seasons.
13. Wyatt Mathisen (C, GCL)
With the Pirates' failure to sign first-round pick Mark Appel, Mathisen becomes the Bucs' top prospect from the 2012 draft.
Mathisen is a valuable addition to a Pittsburgh organization that lacks catching prospects. Given Tony Sanchez' inconsistency and Mathisen's superior hitting tools, Mathisen became the top catcher in the Pirates' farm system the day he signed.
Who will be the next prospect called up to the Pirates?
Mathisen has performed solidly in limited plate appearances since signing, doing nothing to diminish his prospect status.
14. Alex Dickerson (1B, Bradenton)
Alex Dickerson is the latest name in the Pirates' ongoing search for a long-term third baseman. The 2011 third-round draft pick profiles as a league-average starter or better at the position.
Dickerson's performance at Bradenton this season has been underwhelming, and the Pirates would like to see him hit for more power. Yet he is getting on base at a healthy clip and his numbers are certainly not a cause for alarm.
Dickerson edges Matt Curry as the Pirates' top first-base project due to his age (he just turned 22) and pedigree.
15. Nick Kingham (RHP, West Virginia)
Nick Kingham rose up several prospect boards following a strong 2011 season at State College, but his 2012 performance has not held to form.
Kingham has successfully increased his strikeout rate this season, but his other peripherals are poor. His high home-run rate this season has been his largest issue; hopefully that is primarily caused by loosed fastball demand and will be phased out over time.
For now, Kingham has yet to put much distance between himself and the scores of other projectable young pitchers in the Pirates' system.
16. Justin Wilson (LHP, Indianapolis)
Justin Wilson is a polar opposite of his fellow Indianapolis pitchers, capable of dominance and incompetence in any given start.
Control has always been a problem for Wilson, who has walked more than a batter every two innings throughout his career. While he has top of the rotation stuff, Wilson's control issues have prevented him from making the leap.
Given that Wilson is already in Triple-A and still has such severe control problems, it's hard to expect him to become a reliable pitcher for Pittsburgh.
17. Tony Sanchez (C, Indianapolis)
Sanchez's performance over the last three seasons has been disappointing, leaving questions about whether he is truly the catcher of the Pirates' future.
While Sanchez still has a strong glove, he has not had a good offensive season since 2009. A recent hot streak in Triple-A represents his first real display of power in that time frame, but his walk and strikeout rates in 2012 are the worst of his career.
Sanchez may get to the majors soon on account of his defense, but he doesn't look like a long-term solution right now.
18. Barrett Barnes (OF, State College)
Barnes, another 2012 draftee, adds to the Pirates' institutional outfield depth as a consistent all-around performer.
The rookie is off to a strong start to his professional career, with an .873 OPS in 113 plate appearances and equivalent strikeouts and walks. Small sample caveats clearly apply, but it is good to see Barnes starting off his career on the right foot.
As a college hitter, Barnes could move through the system relatively quickly, and he is a nice fallback option if a player like Robbie Grossman doesn't pan out.
19. Matt Curry (1B, Altoona)
Curry forced Pirates' management to notice him last year, when he posted a .671 slugging percentage in 195 plate appearances for West Virginia. Now, he is a part of the conversation regarding the Pirates' first baseman of the future.
Curry has backed up last season's performance with a strong 2012 run in Altoona, compiling an .890 OPS so far this year.
The first baseman has his flaws: He turns 24 next week, he struggled in his Altoona debut last season and he strikes out a lot. But Curry has consistently provided production at a position where the Pirates are very thin, so he remains a name to watch.
20. Clay Holmes (RHP, State College)
The recent struggles with Neal Huntington's strategy of drafting projectable high school pitchers can be seen in the fact that the highest rated of these prospects always seem to be the ones who have not yet had the chance to fail against professional competition.
Such is the case with Holmes, who made his professional debut with State College this season. Holmes has pitched well in his 28 innings, but it's difficult to draw conclusions from 28 innings.
There is still time for the Zack Von Rosenberg's and Quinton Miller's of the world to grow into solid prospects, but so far the early returns on the Pirates' high school pitchers are slim.
Honorable Mentions: Victor Black, Colton Cain, Jarek Cunningham, Brock Holt, Mel Rojas