Jarred Cosart: A Mechanical Analysis

By Zachary Morgan | AstrosBias.com

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     In an effort to help tide you over during the long cold winter, I've decided to do a series of articles breaking down the mechanics of the bright young arms within the Astros organization, and whom better to start with than hurler Jarred Cosart. I'll go into a bit of detail on what makes the righty tick, how he produces the high velocity that he does, how he produces the tight cut on his fastball, and other nuances of his delivery. As a disclaimer, I'm not a bio mechanical guru with a degree in the field, I just picked up a little bit here and there studying what was inducive to the high velocity pitcher and how I could apply my knowledge and research to my own pitching mechanics in college ball. 

Here we see at the start of his delivery as his knee nears peak lift height, he's nearly directly above the rubber. Some refer to this as the "balance position". Cosart uses his leg lift in a similar manner to that of a Clayton Kershaw, he leads with his hip more so, but it's still rather close to being a cut and dry "up, down, & Go" type lift. This balance position holds no benefit in regards to velocity as it acts as a misdirection of mechanical kinetic energy. The traditional train of thought that location is enhanced through the balance position is asinine as well, as proper repetition of mechanics creates consistency within the zone. As you'll see in the next slide Cosart, breaks from the balance point to a degree. 

Jarred reaches his highest point in his leg lift, and you can see his lower half close off towards the middle of the infield accented by the really bad arrow. Also highlighted with an incredibly poorly drawn line is flexion in his back leg as well as a circle identifying the beginning of a hip lead towards the plate. These three points of his delivery allow him to build torsion within his drive leg before he aligns what some refer to as his force vector towards the plate. The hip lead  and flexion signal that he's broken the balance position, and his weight and momentum are beginning to shift towards the plate. 

As his delivery progresses, we can see that his hands break chest high, and a bit late. Late hand break is conducive to higher velocity as it delays arm action, thus aiding hip/shoulder separation. As his lift leg comes down you can see that he isn't making much progress towards the plate and his upper half begins to fold towards second and he begins his load in his drive leg. This is a good foundation for Jarred to build on in reference to his mechanics. 

Jarred begins to lead with and straighten that lift leg as it nears breaking the plane of the hip. He brings the ball down into arm swing and barely moves his glove hand if at all from the still frame above. From here Jarred really loads that drive leg and fires towards the plate, otherwise known as the "gas" phase. There are two key components to delivery in the lower half, the "gas" and "breaking" phase. The Gas phase is where Jarred creates force and momentum through proper linear back leg drive, which you will see in the shots below.

A thing of beauty. Cosart builds deep knee flexion with close to 130 degrees of bend in his back leg creating a powerful drive towards the plate. This powerful drive leg is the foundation for Jarred's velocity. In this shot you can also see another staple of Cosart's delivery, his glove hand. The glove arm comes up to shoulder high pointed towards the third base dugout. Jarred brings his front half back as he continues to lead with his stride leg, and really sits and rotates his body around the drive leg. 

Here the back leg is still in the process of drive and is in the first phase of triple extension. Triple extension is the process of finishing proper leg drive through the hip, knee, and foot, thus creating a velocity vector via ones lower half towards home plate. We can also see that cosart's glove hand continues to elevate above his shoulder as his delivery arm remains low and behind his back. 

Here Cosart has reached triple extension of his push leg before front foot strike, and his leg drive is complete. An indicator that leg drive or triple extension is complete can be found in the drive foot or toe. In this clip you can see Cosart's glove hand continue to come up and around as it raises above his shoulder. As you'll see in the snippets below, Jarred's glove hand and delivery arm go one with the other, as you'll see the delivery arm begin to rise into the cock position as his glove hand comes and tucks into his body. You can see Jarred looking down his sights in this picture as he remains closed and continues to store elastic mechanical energy. 

Jarred has reached front foot strike and he's beginning to transfer his momentum and stored elastic mechanical energy as his leg drive is complete, and his hips begin to open to create elite level hip to shoulder separation. Here we see that his glove has come down and is beginning to tuck into his body, keying his delivery arm to move into a good pre-cock position. His upper body has begun to posture forwards as he begins to drive his chest towards the plate. Notice he had a slight, yet firm bend in his lead leg, this sets him up well for the "breaking" phase. 

Cosart exemplifies a beautiful breaking phase in this point of his delivery leading to hip-to-shoulder separation 101. Powerful linear drive and a closed upper half paired with a lead front leg that shoots straight, acting as a break, allowing the hips to fire via catapult effect into rotational force. Here we see Jarred really drive his chest down and towards the direction of his target as his equal and opposites continue to redirect high and low. This pull down of the glove arm and lift of the delivery arm into the cock position forces him to get on top of the ball at release point, which will lead to cut on his ball regardless of grip at times. We see a good near right angle in his delivery arm as it begins to move into external rotation as the final stage of the delivery begins. 

Here we see Jarred's delivery arm move into complete external rotation as all of his energy is transferred to the top. A delivery is much like a building in that the top floor is dependent on the foundation. Jarred has laid a foundation conducive to velocity through a gas phase to linear leg drive, leading triple extension into hip-to-shoulder separation and the breaking phase. The steps above in Cosart's delivery has built energy appropriated into the still frame we see above as his delivery arm is torqued into external rotation. The rubber band of torsion that is the momentum and force Jarred has created is channeled into his delivery arm as he prepares to fire a mid 90's fastball. 

And here's the finished product. We've reached the top story of the building that is Jarred Cosart's mechanics and the result is a fastball that's about to come in all kinds of hot. Jarred's long arm action may lead to erratic control at times which contributes to his high walk rate, but it also contributes to his ability to cut the ball and remain lower in the zone which gives us his phenomenal ground ball rate. Jarred has efficient power mechanics that allows him to maintain velocity deep into an outing. I would also describe his mechanics as "repeatable" but I hate that phrase in relation to a pitchers mechanics as these are professional pitchers with little to zero trouble "repeating" their mechanics, and that term is better suited in evaluating a young hurler and not one that has reached the professional, much less the major league ranks. Some worry about injury rearing it's ugly head, and the volatility that comes with the health of young starting pitchers. Having already experienced shoulder injury, and exhibiting an inverted W style of arm action, which can increase stress on the shoulder complex, concern isn't unwarranted. The problem with the "inverted W" is that it can create a stress point if timed improperly. If the arm isn't in a cocked position at front foot strike, stress is inflicted on the arm as it torques to reach the cocking position late. As you can see in the first front foot strike picture above, Jarred gets his arm into the cocked position in a timely manner, therefore the inverted W doesn't adversely affect the health of his shoulder complex, but it is certainly something to keep a close eye on and monitor moving forward. Routine video of Jarred's outings and bullpens should be analyzed to ensure that his timing remains proper, and mobility assessments should be made to ensure that there is no excess of inflammation and loss of range in his shoulder cavity. These steps are the best insurance policy to take out on a young pitchers arm, and if the Astros do such, there is no reason to believe that Cosart will not remain healthy and do so in a starting role. Jarred possesses very powerful mechanics and a special gift in his ability to cut the baseball. Look for Cosart to remain a top of the rotation arm, and a cornerstone of  the Astros staffs of the future.