Dallas Keuchel's ground ball success

Dallas Keuchel's 2014 was easily the biggest surprise for myself last season. The ground ball king seemingly came out of nowhere to be one of the better pitchers in baseball. Keuchel finished 2014 with an fWAR of 3.7, which was good for 19th among starting pitchers. The success has translated over to this season as well as his 1.2 fWAR is currently the fifth best among starting pitchers.

Keuchel has never been a strikeout pitcher in college, the minors, and still isn't much of a strikeout pitcher in the big leagues. Of the top 20 pitchers in terms of fWAR last season, Keuchel had the lowest K/9 at only 6.57. So how has he become such a successful pitcher worthy of ace status with the lack of overpowering stuff? Because he's the best at inducing ground balls.

Keuchel's BIP numbers are very extreme. Last year Keuchel led all pitchers in ground ball percentage, as well as ground ball to fly ball ratio. He also surrendered fly balls and line drives at the lowest and fourth-lowest rate, respectively. The trend is looking the same this season as Keuchel is once again leading all pitchers in ground ball percentage and is second in ground ball to fly ball ratio. Here's a look at his batted ball percentages:

Season	GB%	LD%	FB%	GB/FB
2014	63.5%	17.2%	19.3%	3.3
2015	63.8%	18.4%	17.7%	3.6

Keuchel is obviously is pitch to contact guy, and that's exactly what you're going to get out of a guy who's not overpowering and sits 89-91 with his two-seam. But, it's his two seam that he relies on so heavily and has had so much success with. His two seam has less armside run than a typical two-seam, but does have a natural sinking action which leads to the ground ball success. In 2014, Keuchel's GB/BIP was over 80 percent, while this year is sitting dead on at 75 percent.

Keuchel's two-seam fastball is very interesting to me. A good two-seam fastball will have good arm side run on it that pitchers like to throw inside to a same-handed batter as the arm side run will jam the batter and induce weak contact on the handle. It is also effective when trying to backdoor and paint the outside corner with the late arm side tail. This is where the two seam is effective for righty v. righty matchup, or lefty v. lefty matchup.

Generally, it seems that right-handed pitchers throw a two-seam fastball more often than lefties do. There are also more right-handed batters than left-handed batters. The arm side tail is great when pitching away to an opposite handed batter as the late tail will make the two-seamer look like it's painting the black, but will tail away and end up off the plate. This arm side tail is what makes it difficult to come inside on an opposite handed batter. When throwing to the inside corner, the late tail can carry the pitch over the heart of the plate. You might be asking yourself, "why not just aim more inside and have the tail carry it to the inside corner?" Well, it's easier said than done. Throwing at the batter's hip so that the tail can hit the inside corner is a tough thing to do.

Because Keuchel has less armside, there is something that has stood out about him. He is able to pound his two-seamer inside to not only lefties, but to righties as well. Here's his zone profiles on his two-seam fastball from 2014-2015 against both righties and lefties.

Here's a video of Keuchel's two-seam inside on a righty resulting in a ground ball. (Try to focus on the pitch, its location, and ground ball result rather than the great play by Luis Valbuena.)

keuchel_video.0.mp4

He's been able to throw his two-seam fastball inside to batters on both sides of the plate at a substantial rate, and as the numbers of above show, he's had great success with it. We know the outcomes, but what about his overall repertoire?

Keuchel primarily throws his two-seam fastball, slider, changeup, and occasionally mixes in a four-seam and cutter. To determine his overall repertoire, we can't just look at the overall percentage of the time he throws his pitches, but rather when he throws his pitches.

We know he throws his two-seamer a lot, 47 percent of the time to lefties, and 49 percent of the time to lefties. What stands out is not the overall percentage of the time he throws it, but when he throws it.

When Keuchel got the call up to the big leagues, he was primarily a two pitch pitcher: a sinking two-seam fastball, and plus change, with a weak curve.Keuchel has added another average to plus pitch in his slider. It has proven to be a successful out pitch for him that has greatly improved his success as a starter. In order to be a successful starter in the big leagues, you must have multiple pitches because as each time a team goes through the order, batters see what you have and are able to attack it better. Adding the slider may have saved Keuchel from being banished to the pen. Having three pitches in his two seam, change, and slider that are all effective and close to equal in quality, Keuchel is able to mix his repertoire effectively when ahead.

From 2014-2015, when ahead in the count against righties, Keuchel has almost evenly used his two-seam, slider, and change. Against lefties when ahead, it is essentially 50-50 with his two-seam and slider as out pitches. His repertoire when behind in the count is much different.  When behind, Keuchel is relying on his two-seamer roughly 60 percent of the time, and mixing in a slider against lefties, and a change against righties.

No pitcher wants to get behind in the count, but Keuchel is extremely effective when ahead in the count because of his ability to mix three equally valuable pitches that keeps hitters guessing. Well, it's a good thing that Keuchel gets the first pitch strike at an impressive rate. In 2014, Keuchel got the first pitch strike 65.4 percent of the time, and 62.4 percent of the time this season, which makes him one of the best in baseball at doing so. This ability to get the first pitch strike not only allows him to mix his pitches when ahead, but it allows him to stay out of the zone with his pitches as his pitches have only been in the zone 44.3 percent last season, and 41.7 percent of the time this season.

Keuchel is definitely not a thrower, but rather a great pitcher. He has come out of nowhere to being worthy of ace status. He doesn't over power hitters, but he's able to induce ground balls at an extremely high rate. He's added the slider to his repertoire which may or may not have saved his position in the rotation.


All statistics courtesy of Brooks Baseball, FanGraphs, and Baseball Reference.

Brandon Decker is a contributor at Beyond the Box Score as well as BP Wrigleyville. You can find him on Twitter @bdeck02.