Midseason Top Prospect Trades

How often are top prospects traded midseason?  Using trade periods of June through August, and Baseball America's preseason top 100 prospect lists, let's take a look at the last four years:

• 2012: 7 (Jacob Turner, Arodys Vizcaino, Jean Segura, Zack Cox, Allen Webster, Nate Eovaldi, Christian Villanueva)
• 2011: 5 (Jonathan Singleton, Alex White, Zack Wheeler, Drew Pomeranz, Jarred Cosart)
• 2010: 3 (Justin Smoak, Brett Wallace, Wilson Ramos)
• 2009: 7 (Brett Wallace, Tim Alderson, Carlos Carrasco, Gorkys Hernandez, Aaron Poreda, Lou Marson, Chris Perez)

If recent history is any indication, we should expect between three and seven top 100 prospects to be traded this summer.  Out of the 22 prospects traded in the last four years, only three were top 30 guys: Smoak, Turner, and Wallace in 2010.  Wallace's 2010 trade was something of a prospect challenge trade, however, and is an exception.  It's fair to expect most traded prospects to be in the 40-100 range on the rankings.  Of those prospects on BA's 2013 list, 33 play for teams currently above .500:

• Red Sox: Matt Barnes, Allen Webster, Henry Owens
• Braves: Julio Teheran, J.R. Graham
• Athletics: Addison Russell
• Pirates: Gregory Polanco, Alen Hanson, Luis Heredia
• Rockies: Nolan Arenado, David Dahl, Trevor Story
• Reds: Robert Stephenson, Tony Cingrani, Daniel Corcino
• Yankees: Gary Sanchez, Slade Heathcott, Tyler Austin
• Rays: Taylor Guerrieri, Hak-Ju Lee, Jake Odorizzi, 
• Giants: Kyle Crick
• Nationals: Lucas Giolito, Brian Goodwin
• Diamondbacks: Adam Eaton, Didi Gregorius, Matt Davidson
• Tigers: Avisail Garcia, Bruce Rondon
• Cardinals: Michael Wacha, Kolten Wong
• Rangers: Martin Perez, Leonys Martin

Players like Teheran and Arenado seem less likely to be traded, as they're holding down full-time roles.  Also, since top 100 prospects are created prior to the season, they don't account for prospects whose stock dropped in the minor league season leading up to the trade deadline, such as Turner, Alderson or Cox, or others whose stock rose.  Vizcaino is an example of an injured prospect who was traded, but it seems unlikely in the case of the Rays' Lee, who is probably out for the season due to a knee injury.  

We also have to consider team and GM history.  Even if my brief four-year sample, the Phillies traded four of the 22 prospects in a pair of major trades, but the club may not profile as a buyer in two months.  A player like the D'Backs' Davidson seems to represent the perfect storm of a summer prospect trade: he's a bit of a forgotten prospect, he's blocked at third base, and he plays for a contender.

One other factor is the new CBA.  The inability to spend significantly over slot  in the draft may compel teams to hold onto top prospects more tightly, while the inability to recoup value on a rental in the form of draft pick compensation may limit trades of those players.