Two years ago, we examined the history of prospects traded at the non-waiver trade deadline and found less than 20 percent of them went on to have consequential major league careers.

We've now added two more years of data—2013 and 2014— to the sample. Players traded as prospects in 2015 or later are still largely making their way up the minors or are at the start of their major league careers and cannot be fully evaluated yet.

The success rate improves with the addition of the prospects traded in 2013 and 2014 deadline trades, but overall the needle does not move significantly.

In all, 86 of the 428 prospects traded in July deals from 2003-2014 went on to play the majority of at least two seasons in the major leagues and post a positive career WAR, as measured by Baseball-Reference. That's just 20.1 percent of all prospects moved in such trades.

There are big hits among them to be found, however. Corey Kluber, Josh Donaldson, Adrian Gonzalez and Nelson Cruz were all traded as prospects in July deals. So were Jean Segura, Eduardo Escobar, Kyle Hendricks and Patrick Corbin. Mitch Haniger, Addison Russell and Josh Hader were among those were dealt in the most recent years of our sample, 2013 and 2014.

But, by and large, such players are the exception. Much more often than not, prospects traded at the deadline fail to make any significant impact in the major leagues.

Year Prospects Traded MLB Careers Pct 2014 34 10 29.4% 2013 28 7 25.0% 2012 48 13 27.1% 2011 42 6 14.3% 2010 43 13 30.2% 2009 43 5 11.6% 2008 30 8 26.7% 2007 27 7 25.9% 2006 36 5 13.9% 2005 21 1 4.8% 2004 27 4 14.8% 2003 49 7 14.3% Total 428 86 20.1%

*MLB career defined here as the majority of two or more seasons on a major league roster AND a positive career WAR.

Here is the complete data set of the results. Bolded players went on to play at least two majority seasons in the majors and produce a positive career WAR.

2014: Harold Riggins, Addison Russell, Billy McKinney, Zach Borenstein, Joe Krehbiel, Cesar Carrasco, Alex Sogard, Spencer Patton, Trevor Gott, Taylor Lindsey, Jose Rondon, R.J. Alvarez, Elliot Morris, Rafael De Paula, Corey Knebel, Jake Thompson, Stephen Pryor, Edwin Escobar, Heath Hembree, Jonathan Martinez, James Ramsey, Corey Littrell, Anthony Banda, Mitch Haniger, Stephen Kohlscheen, Eduardo Rodriguez, Zach Walters, Peter O’Brien, Enrique Hernandez, Austin Wates, Colin Moran, Francis Martes, Victor Caratini, Willy Adames.

2013: Steve Ames, Josh Wall, Angel Sanchez, Ivan Pineyro, Russ Canzler, Tim Alderson, Brandon Jacobs, Parker Frazier, Carl Edwards Jr., Mike Olt, Justin Grimm, Neil Ramirez, Nicky Delmonico, Corey Black, Danry Vasquez, Cory Rasmus, Juan Herrera, Joe Thatcher, Matt Stites, Kyle Smith, L.J. Hoes, Josh Hader, Avisail Garcia, Brayan Villareal, Frankie Montas, Cleuluis Rondon, J.B. Wendelken, Grant Green.

2012: Matt Dominguez, Rob Rasmussen, Todd Redmond, Carlos Perez, Asher Wojciechowski, Joe Musgrove, David Rollins, Kevin Comer, Matt Heidenreich, Blair Walters, Chris Devenski, D.J. Mitchell, Danny Farquhar, Jacob Turner, Rob Brantly, Brian Flynn, Robbie Grossman, Rudy Owens, Colton Cain, Tyler Bortnick, Nate Eovaldi, Scott McGough, Jean Segura, Johnny Hellweg, Ariel Pena, Charlie Culberson, Eduardo Escobar, Pedro Hernandez, Bobby Borchering, Marc Krauss, Jake Brigham, Arodys Vizcaino, Jaye Chapman, Leon Landry, Logan Bawcom, Ethan Martin, Stefan Jarrin, Tommy Joseph, Seth Rosin, Zack Cox, Gorkys Hernandez, Kyle Kaminska, Juan Carlos Sulbaran, Donnie Joseph, Steven Wright, Lars Anderson, Kyle Hendricks, Christian Villanueva.

2011: Danny Ray Herrera, Adrian Rosario, Henry Sosa, Jason Stoffel, Julio Rodriguez, Antonio Cruz, Bill Rhinehart, Chris Manno, Zach Stewart, P.J. Walters, Zack Wheeler, Carlton Smith, Abner Abreu, Jonathan Singleton, Jarred Cosart, Josh Zeid, Domingo Santana, Francisco Martinez, Chance Ruffin, Erik Komatsu, Kendal Volz, Yamaico Navarro, Zach Walters, Drew Pomeranz, Alex White, Joe Gardner, Matt McBride, Thomas Neal, Aaron Baker, Alex Castellanos, Brett Oberholtzer, Paul Clemens, Juan Abreu, Jordan Norberto, Robbie Erlin, Joe Wieland, Tim Federowicz, Stephen Fife, Juan Rodriguez, Trayvon Robinson, Chih-Hsien Chiang, Josh Fields.

2010: Michael Main, Blake Beavan, Josh Lueke, Matt Lawson, Tyler Pastornicky, Tim Collins, Sean O'Sullivan, Will Smith, Patrick Corbin, Rafael Rodriguez, Tyler Skaggs, Giovanni Soto, Lucas May, Elisaul Pimentel, Anthony Gose, Jonathan Villar, Brett Wallace, Evan Reed, Omar Poveda, Wynn Pelzer, Wilson Ramos, Joe Testa, David Holmberg, Ryan Tatusko, Tanner Roark, Zach McAllister, Jimmy Paredes, Mark Melancon, Matt Gorgen, Pedro Ciriaco, Corey Kluber, Nick Greenwood, Brett Wallach, Kyle Smit, Wilkin Ramirez, Andrew Lambo, Matt Cusick, Andrew Shive, Gregor Blanco, Chris McGuiness, Roman Mendez, Michael Thomas, Dan Turpen.

2009: Al Alburquerque, Jon Meloan, Craig Italiano, Ryan Webb, Brandon Allen, Dan Cortes, Derrick Saito, Cole Gillespie, Roque Mercedes, Argenis Diaz, Hunter Strickland, Connor Graham, Brett Wallace, Clayton Mortensen, Shane Peterson, Scott Barnes, Nathan Adcock, Brett Lorin, Aaron Pribanic, Carlos Carrasco, Jason Knapp, Jason Donald, Lou Marson, Tim Alderson, Robert Manuel, Josh Bell, Steve Johnson, Kevin Hart, Jose Ascanio, Josh Harrison, Mauricio Robles, Luke French, Tyler Ladendorf, Chase Weems, Zach Stewart, Aaron Poreda, Adam Russell, Dexter Carter, Nick Hagadone, Bryan Price, Ryan Mattheus, Robinson Fabian, Aaron Thompson.

2008: Matt LaPorta, Rob Bryson, Zach Jackson, Michael Brantley, Sean Gallagher, Matt Murton, Eric Patterson, Josh Donaldson, Evan Scribner, Adrian Cardenas, Josh Outman, Matt Spencer, Steve Hammond, Darren Ford, Emilio Bonifacio, Chad Reineke, Jose Tabata, Ross Ohlendorf, Dan McCutchen, Jon Meloan, Carlos Santana, Luis Perdomo, Stephen Marek, Danny Richar, Gaby Hernandez, Alberto Gonzalez, Andy LaRoche, Bryan Morris, Craig Hansen, Brandon Moss.

2007: Chris Cody, Danny Christensen, Jerry Blevins, Jeff Kennard, Will Inman, Joe Thatcher, Steve Garrison, Max Ramirez, Michael Dubee, Leo Rosales, Calvin Medlock, Brian Shackelford, Shaun Cumberland, Jarrod Saltalamacchia, Elvis Andrus, Matt Harrison, Neftali Feliz, Beau Jones, Matt Maloney, Drew Butera, Sean Danielson, Jon Link, David Murphy, Engel Beltre, Jesus Merchan, Will Startup, Steve MacFarland.

2006: Terry Evans, Travis Chick, Mitch Talbot, Ben Zobrist, Brendan Harris, Daryl Thompson, Jeff Keppinger, Max Ramirez, Joel Santo, Fabian Jimenez, B.J. LaMura, Tyler Lumsden, Daniel Cortes, Blake Johnson, Julio Pimentel, Shin-Soo Choo, Shawn Nottingham, Laynce Nix, Julian Cordero, Nelson Cruz, Shairon Martis, Wilfrido Laureano, C.J. Henry, Matt Smith, Jesus Sanchez, Carlos Monasterios, Justin Germano, Brian Rogers, Zach Ward, Joselo Diaz, Jose Ceda, Jesse Chavez, Joel Guzman, Sergio Pedroza, Denny Bautista, Scott Dohmann.

2005: J.J. Davis, Doc Brooks, Omar Quintanilla, Jason Dubois, Chip Ambres, Juan Cedeno, Matt Lorenzo, Matt Kata, Travis Chick, Justin Germano, J.J. Furmaniak, Eduardo Sierra, Ramon Ramirez, Nathanel Mateo, Kyle Bono, Kenny Perez, Ryan Meaux, Yorman Bazardo, Mike Flannery, Roman Colon, Zach Mine.

2004: Peter Ciofrone, Jon Rauch, Gary Majewski, John Hattig, Scott Kazmir, Joselo Diaz, Bartolome Fortunato, Justin Huber, Jeff Keppinger, Matt Peterson, Jose Bautista, Alfredo Simon, Jon Huber, Bill Murphy, Anderson Machado, Brad Correll, Josh Hancock, Abraham Nunez, Matt Merricks, Travis Chick, Koyie Hill, Reggie Abercrombie, Henri Stanley, Justin Jones, Brendan Harris, Francis Beltran, Matt Murton.

2003: Royce Ring, Edwin Almonte, Andrew Salvo, Anthony Webster, Josh Rupe, Frank Francisco, Alejandro Machado, Wes Obermueller, Scott Mullen, Victor Rodriguez, Gookie Dawkins, Scott Dunn, Adrian Gonzalez, Will Smith, Ryan Snare, Clay Hensley, R.D. Spiehs, Victor Diaz, Joselo Diaz, Kole Strayhorn, Dave Gassner, Anderson Garcia, Ryan Bicondoa, Jason Anderson, Mike Watson, Ryan Ludwick, Frank Brooks, Anastacio Martinez, Mike Gonzalez, Matt Bruback, Bobby Hill, Jeremy Hill, Kenny Kelly, Scott Dunn, Tim Bittner, Phil Dumatrait, Tyler Pelland, Jon-Mark Sprowl, Jason Fransz, Jeff Bruksch, Joe Valentine, Charlie Manning, Brandon Claussen, Freddy Sanchez, Anastacio Martinez, Ryan Hannaman, Scott Proctor, Bubba Crosby.