July 30, 2010 – Tanner Roark
The top two trades on this list both took place before the 2010 trade deadline, a season in which the Washington Nationals ended up finishing in the cellar in the NL East. This was the second of the two trades they made leading up to the deadline, but it landed the Nats one of their current starting pitchers.
With Ian Kinsler on the disabled list at the time, the Texas Rangers were looking for some help in the infield. So, the Washington Nationals dealt infielder Cristian Guzman to Texas for pitchers Ryan Tatusko and Tanner Roark.
Of course, Roark is the name everyone remembers from this trade. He made his Major League debut with the Washington Nationals in 2013 and is 36-24 in his four seasons with the Nats. This includes a 15-win season in 2014 with a 2.85 ERA and his ten wins so far this season (2.96 ERA).
As for Tatusko, he never made it up to the Major Leagues as his final season in the Nats organization came in 2014 with triple-A Syracuse (5-5, 2.85 ERA in 14 starts). He ended up playing part of the 2014 season in Korea as well.
Meanwhile, Guzman barely saw the field for the Rangers. He played in 15 games for Texas and hit .152 during that stretch. Texas made the postseason that year, but Guzman didn’t get to play. In the end, the Nats won this deal mainly because Roark has been one of the keys to their rotation in two of the last three years.
Next: Number 1