Nate Karns and Useful Spin
When the Rays acquired Nate Karns from the Nationals back in 2014, the story was that he had fastball velocity and a power curve, and we’ll see about the changeup. We saw the changeup, and it was good enough, and the curve was as advertised. Unfortunately, something happened to the fastball along the way.
The Rays sent Jose Lobaton and Felipe Rivero to the Nationals for that curveball and hoped on the change. The change looked good in 147 innings for the Rays in 2015, so the Mariners took a leap that offseason, sending Brad Miller, Logan Morrison and Danny Farquhar to the Rays for Karns, right-hander C.J. Riefenhauser, and center fielder Boog Powell. Now, after a poor year, Karns has been traded again — to the Royals, this time — for outfielder Jarrod Dyson.
What happened last year, when Karns had an ERA over five? The curve and the change were fine in Seattle! But in the meantime, something may have happened to Karns’ fastball. And it could have to do with useful spin. Kansas City has to hope that what broke is fixable.