Jake McGee should throw more curves

Editor's Note: It's possible that Jake McGee may not even be a Rays reliever next season, due to his rampant trade interest and the Rays' incentives to deal him, but if he stays there's an easy way for the already great reliever to up his game in 2016...

Since reaching the big leagues with the Tampa Bay Rays in 2010, Jake McGee has been known as a one-pitch pitcher. Over the course of his career, the southpaw has thrown 89 percent four-seam fastballs. This approach has been quite successful as he has put together a 2.77 ERA, 11.06 K/9 and 2.50 BB/9 thanks to his ability to locate his upper-90’s heater.

What Jake McGee has not done in his career is throw breaking pitches.

In his first extended action in the bigs in 2011, he did tinker with a slider and curve, throwing them a combined 16.6%. However, he ditched the curve for the 2012 and 2013 seasons, increasing his fastball usage both years in the process. In 2014, there was a re-emergence of the curve, but he still threw it just 3.5% of the time while he threw his fastball a career-high 96.5% percent of the time.

McGee clearly knows his strength, and that is a nasty fastball that he can locate at will. That said, after his 2015 season, could we see McGee throwing more curves moving forward?

Last season, McGee decreased his fastball usage for the first time in his career (not counting from 2010 to 2011 as he made just 8 appearances in 2010), throwing it "just" 92.69 percent of the time. The pitch was once again a successful one for him, and opposing batters hit it to the tune of just a .213 average and .323 slugging percentage, right in line with his career .207 and .310 marks.

On the other hand, the pitch saw a dip in velocity to an average of 95.6 mph, the slowest he has thrown the pitch since 2011, and a marked decrease over its 97.5 mph average in 2014. The reasoning behind this decrease could be debated. He did open the season on the disabled list after off-season elbow surgery, and he also made just three appearances after August 18^th thanks to knee issues. Also, at 29, he is not old, but he certainly is not getting any younger.

We cannot say for sure if McGee’s fastball velocity has dropped for good or if it can rebound next season. However, if it has indeed dropped, then that could be reason a for him to throw his curveball more.

The biggest reason why McGee could look at throwing more curves, though, is the fact that it has been an effective pitch for him. Of the 135 curves he has thrown in his career, batters have hit just .172 against the pitch with no extra base hits.

Opposing hitters have also posted a whiff per swing rate of 46% against the pitch, much better than the 25.6% of his fastball. The curve stayed successful last season with batters not even managing a hit against it in 45 tries.

Here’s a look at McGee striking out Mike Napoli with a curveball.

This is no Clayton Kershaw curveball, but it looks to be a solid pitch nonetheless. Of course, the reason for the success of the pitch is that hitters almost never expect it to be thrown given the fact that he throws so many fastballs. They are always focusing on his fastball, so a curve down in the zone or low and out of the zone fools batters. But would this change even if he threw his curveball 15% or 20% of the time?

Pitch interactions can be difficult to predict, but I don't think it would.

McGee is not going to simply change the type of pitcher he is. Even if his fastball velocity never averages 97 again, it is still a great pitch that will be effective even at 94-95 thanks to his ability to locate it. That said, McGee’s curve has worked well for him since he brought it back to his arsenal, and throwing it a more often next season makes plenty of sense.

Pitch data used in this article is courtesy of Brooks Baseball.