BP recently visited with Tom House at the National Pitching Association (NPA) lab in San Diego and observed him instructing some youngsters at his mini-camp. One of those students, Aaron Cross, is a ten-year-old who has been working with House since age six. Among other things, House has taught Cross to throw a hammer curve properly. In addition to seeing Cross and other youngsters, we also got a chance to see NPA’s high-speed motion analysis system.

Baseball Prospectus: You last spoke to BP a couple of years ago. Just to get started, what’s new at NPA since then?

Tom House: Probably our relationship with Titleist golf. They have 30,000 golfers in the computer with the same technology we have, which is a significantly larger sample than our 447 major league pitchers. But the similarities between a golf swing, batting, and pitching are unbelievable. By looking at what they’ve done with their golf signature and looking at what we’ve been doing, I think we’re finally realizing you pretty much leave the gene pool alone and you position the gene pool on the rubber to accommodate what that youngster does–throwing across his body, striding straight or straight slightly open–and you spend time teaching timing than you do mechanical changes. If you change a pitcher’s signature, you run the risk of diminishing what his gene pool might be capable of doing. So, what you need to understand–and it’s hard–is just give an individual better timing with what he does genetically. We also have to be strong enough and flexible enough to handle the pitch totals that are being asked out of them because without strength to support workloads, mechanics will come apart.

You’ll have in hand the state-of-the-art stuff we have. We actually compare a pitcher’s signature and golfer’s signature in the books. And what Doug [Thorburn] is going to show you, we have in the computer an eight-year-old all the way up to the superstars, and the signatures are the same. It’s scary. It kind of makes irrelevant most of what we pitching coaches have been teaching for the last 50 years… with good intentions.

BP: The overarching purpose of our discussion today is to talk pitching mechanics, particularly safety in youth pitching. Are there any particular points you’d like to open up with in that regard?

TH: With youth pitchers, breaking balls and split fingers are high-risk pitches if thrown improperly. To abstain from throwing them is probably the safest thing to do, but it will put the development of pitchers in the United States way behind what’s going on in Latin America and the Pacific Rim. I’m a proponent of teaching the right way, biomechanically, and of strength training to support the mechanics and then making sure pitch totals and pitch ratios reflect what research says are the correct ratios. In other words, if you keep pitch totals and the ratio of fastballs, breaking balls, split-finger or change-ups at the numbers we’ve generated, which are 60-65% fastballs, 20-25% breaking balls and 15-20% change-ups… if you keep those ratios and the number of pitches per inning and per game, which have already been researched and understood worldwide, then the risk of injury while developing command of the breaking ball and split-finger is minimized. So with better information and instruction, I think we can do the same thing as abstinence.

BP: When Aaron warmed up, he reached back rather well and appeared he would come over the top, but at the last second would drop and come from about 45 degrees. The arm action was reminiscent of Billy Wagner. Is that good, bad, or indifferent?

TH: Research has revealed to us that pitchers have signatures. They are born with how they would throw a rock at a rabbit to eat. There are some conventional wisdoms that get in the way of that genetic signature: get on top, don’t throw sidearm, don’t short-arm the ball, reach back. There’re a number of them. But in effect, you should just leave whatever a pitcher does, whatever a kid does when he’s throwing a baseball with his throwing arm, just leave it alone. That’s his gene pool talking. The fix is actually in the front side. If you match up with balance and posture, into foot-strike, whatever the throwing arm is doing, the glove side is a mirror image, then what’s going to happen is genetically predetermined. There is no perfect forearm angle. Over-the-top works for about 25% of the pitching population. Most pitchers are three-quarters. That would be why to our eye they appear to be most the appealing, because we see the most of that. Twenty percent throw sidearm and there’s about 3-5% that throw below sidearm, the submarine guys. But all of the them are equally efficient, based on what the arm does relative to the spine, relative to release point, if into foot-strike you have balance, posture, opposite and equal, hips deliver shoulders, shoulders deliver arm. The arm belongs to the kid, not to you and me and us to dictate what the arm slot should be. So long story short, leave the throwing arm alone; it’s genetically predetermined.

BP: So concerns about stress on the arm based on arm slot …

TH: If you really want the true words… it’s all b!#$s&*^. There’s no more stress throwing sidearm than there is over the top… if they balance, posture, opposite and equal, hips deliver shoulders, shoulders deliver arm, and there’s no late posture changes, the spine stays upright, the arm happens. Four million years ago someone threw rocks at rabbits to eat. We’re throwers by species. Somehow, someway pitching coaches have gotten in the way of what that kid would do if he was throwing rocks at rabbits to eat. Young pitchers, old pitchers, veteran pitchers, rookies. The more time you give them to screw something up, the more things they’re going to screw up. The weaker they are, the longer they tried to keep a position, the harder it is to get the body going. You never tell a shortstop what to do with his arm. If they had the same momentum into foot strike as a pitcher as they did throwing across the infield, many of our problems would go away.

BP: So when you teach the proper way to throw a curve ball, does it really start with everything besides the arm?

TH: Every pitch is thrown with the same mechanics, except for what wrist and forearm do. The biggest problem that youth pitchers have is they believe they have to twist to throw a breaking ball. And it’s not necessarily the twist that causes the problem. Our 1000-frames-per-second motion analysis has revealed that it’s the twist and the untwist, the amount of intensity that goes with the degrees of trying to spin the ball and then decelerate the arm. After every throw, no matter what position you are on a baseball field, when the ball leaves your hand, your palm will pronate into deceleration. The palm turns out [like throwing a screwball] so the reason a breaking ball is so hard on the elbow is that the kid is trying to twist into [his] release point to create spin, then he’s twisting and untwisting in the same amount of time, and the stress on the elbow joint grows exponentially greater while the arm is snapping straight.

So the fix for the whole thing is to preset stabilize. Start with the karate chop in the glove, come out and karate chop the curve ball. There is no spin. Karate chop the curve ball, which puts the palm on the outside of the ball, the thumb and middle finger cutting through the middle of the ball, and that’s what imparts proper rotation, safely. So whatever angle, if your palm is straight at the catcher, it’s a fastball. If you start getting towards karate chop, if you go one click, it’s a slider. Two clicks, slurve. Three clicks, curve ball. And the idea is to find whatever pitch, whatever breaking ball you want, preset that angle and keep that angle with the same mechanics your body has with a fastball from the time your hands break into release point and risk of injury is minimized.

BP: When I was a youth trying to throw a curve ball, I could never get enough snap on it. I could throw something with spin, but it would float. Trying different grips and pressure points didn’t produce much better results. How do you teach somebody to really snap a breaking ball?

TH: Every pitch, no matter what you’re going to throw, thumb and middle finger have to cut through the middle of the baseball. And with that set, you create angle with wrist and forearm. The leverage of thumb and middle finger–because the baseball is going to leave your middle finger last–and you have to make sure that the thumb creates the leverage through the critical mass of the ball and around that axis, you change the angle of your wrist and forearm. If you deliver the pitch with fastball arm speed and that angle of pitch, angle of breaking ball, then there’s less stress with the same amount of arm speed, but the ball won’t go as fast because you’re imparting rotation rather than force on the baseball.

The reason that you had trouble as a youngster spinning a curve ball is the arm can snap straight forward at about 1/750 to 1/700 of a second, and you can only twist at 70 degrees of angular velocity, so setting the angle and delivering with fastball arm speed puts a lot more spin on a ball than trying to actually rotate the ball. So, it’s the laws of physics.

But unlike the research we have now, you probably experimented or someone told you you had to, you know, you seen that one where you snap fingers? That’s just BS. Baseball is a game of failure, coached by negative people in a misinformation environment. And the reason for that is the human eye can only see about 32 frames per second and most of what takes place in a delivery takes place at 1/700 to 1/250 of a second.

BP: If that’s the case, then what is it you can see in a delivery? What can you watch for if you are coach in the dugout–or even if you are a catcher in the game–that would give you any positive or negative indications about a pitcher’s delivery? And what can’t you see?

TH: Watch what the head does. Once they start forward, the head should stay parallel to whatever surface they’re on, whether it’s flat ground or the mound. It shouldn’t go east or west, the spine should stay on line. At foot strike, it should look symmetrical or mirrored or opposite and equal. The spine should stay upright as long as possible while hips deliver shoulders in rotation, the eyes stay up in to release point, the glove stays over the front foot, and the body goes to the glove. Those things you can see.

The violence of internal rotation and external rotation, the speed of hip and shoulder after they’ve created a degree of separation, that’s a little bit beyond what the human eye can see. If the ball, on anything but a fastball, goes above the fastball plane at release point, then the pitcher manipulated the ball, meaning imparted a spin on it. And if he’s manipulating, he’s going to hurt his elbow or shoulder. So, in a perfect world with the coach watching what’s going on, watch the head, watch the posture, watch the opposite and equal, watch the chest go into the glove, watch release point for all three pitches coming out of the same release point. If it goes above fastball release point, then the pitcher’s trying to manipulate. If the pitcher’s trying to manipulat(e), he’s changing angle while the arm is snapping straight and he’s going to hurt himself.

BP: Is that not what Barry Zito does? It seems like on his curve, the ball pops out of his hand and drops in.

TH: Barry Zito, Tom Gordon, Nolan Ryan, Bert Blyleven, Aaron Sele. They’re pitchers that get away with it because it breaks so much. If you take a normal, run-of-the-mill pitcher, not an elite Barry Zito, they can’t put the spin on it that those guys do. So a ball that goes above the fastball plane is a hanging curve ball. With those guys, it just keeps biting. They’re able, because they have arm speed, as well as whatever they’re doing, whatever magic they’re creating, there ball sizzles out of their hands. When you turn your back on Nolan Ryan or Barry Zito, you can’t tell from the sound of the ball out of their hands whether the leverage is coming from a breaking ball or a fastball. It’s talent and skill. It’s a combination of angular momentum and linear momentum happening, perfectly. To flip-flop the argument, if they threw that big of a breaking ball out of a fastball plane, it would never get to home plate. So they’ve altered their trajectory.

BP: Are they letting it loose a little bit earlier?

TH: No. The release point for all these guys, if they’re throwing strikes, is within three-quarters of an inch on all three pitches, because for every 1/8th of an inch your middle finger misses middle of the baseball, it’s eight inches at home plate. So if they’re two inches back on one pitch and two inches forward on another, they’re going to be huge up and down at home plate. So, it’s very predictable. It can be taught. If taught properly, they’ll learn and they’ll accommodate, which you’ll kind of see with the drills here. All the drills that we have are cross-specific to the movement required of actually pitching the baseball.

BP: Getting back to Aaron just for a moment, in his wind-up he doesn’t actually rock back. He’s steps right into moving forward. Is that taught?

TH: At that age, we try to minimize the amount of body movement. Anything other than forward for a youngster at that age is very difficult to compensate for. The only thing that matters is first forward movement. So from wind-up and stretch, if you get a kid moving forward without any side-to-side or away from home plate movement, he’s more able to not only handle the stresses of throwing, but time the stresses of throwing. They’re more efficient.

BP: Do you teach anything specific about posture or balance when your knee is raised?

TH: If you think about it, whatever you do when you move where you have no head movement, you’ll see all kinds of styles. It’s all style. We don’t mandate. We’d like you to lift your leg as high as you can, or take it away from home plate as far as you can to keep your leg off the ground as long as you can while you’re moving forward in order to make your stride as long as possible. The longer your stride, the closer you are to home plate at release, the more perceived velocity you’re going to have. So we actually, based on what the kid does naturally, try to minimize head movement, make sure momentum is all going forward, while rotational momentum is timed, and we want to get them as far as fast as possible to get release point closer, quicker to home plate.

BP: In conventional wisdom, stride is much more complicated, but it sounds like all you want is as long and as fast a stride as possible. Is there such thing as overstriding?

TH: You can’t overstride… unless you change posture when you’re overstriding. If you keep your balance and your posture, if you keep all those things we talked about in our sequence. Nolan Ryan at 6’1″ had an 83″ stride. Randy Johnson, who we’re watching right now, at 6’11” strides 90% of his body height. The average major leaguer will stride 90% of his body height, measured from front of rubber to the furthest point his front toe reaches.

BP: So you don’t teach anything about whether the front knee should be bent or straight or… just check for the glove.

TH: That’s someone mandating what might be unnatural to a pitcher. You don’t want to fiddle with their signature. Basically, if their head stays on line while their body is shifting its weight, they’ve done their job. Do you ever tell a middle infielder what to do with his knees when he’s throwing across the infield? Why would you tell a pitcher? See the problem we get into? We over-coach. And we over-coach the wrong things. Me included. I’m not pointing fingers.

BP: Back to the last BP interview again for a moment, you mentioned you have developed a pitching model that is more coaching-specific than ASMI’s medical model. Can you explain what you mean by that a little more?

TH: It’s actually quite concrete. The medical model measures joint stresses. They can actually tell you how many ergs a joint experiences with a 90 MPH fastball. What the medical model can’t tell you is why. What we have as coaches is that we knew what a good delivery looked like, but we didn’t know why. We had the what and didn’t know why. They’ve got “this is what goes on in a joint” but they didn’t have why either. So, recently the two have kind of matched up. The information that’s coming out of ASMI, the information that’s coming out of the Kerlan-Jobe clinic, for not just pitching but gait analysis it just measures joint stresses. But the steeper the mound or inefficient the mechanics, the greater the joint stress is. So, what you want to do is minimize joint stresses by improving mechanical efficiency, useful strength, and monitoring pitch totals.

BP: Before we end, I want to make sure to ask you about one of your poster children, Mark Prior. He’s lauded for having pristine mechanics, and while he’s had a few freak injuries, he’s also had some arm woes. Why is that?

TH: Remember what we talked about the beginning. Mechanics, functional strength, and workload. He’s been overworked.

BP: Getting back to Aaron, and youth pitchers in general, what is it that you’d like to contribute to the American youth pitching environment?

TH: I want every kid that comes through this system to leave here with a tool kit, by which he can construct his delivery, his strength, his nutrition, and his thinking/feeling processes on his own. In other words, he makes better choices because he’s aware, because the problem isn’t so much the fact that there’s bad people out there, it’s bad information. I don’t think there’s a coach out there with bad intentions, but bad information with good intentions is almost worse than no information at all. Kids left to their own devices will figure out things better than a coach that’s misinforming them.

Also, it’s really easy to work with a talent, a Nolan Ryan, an Orel Hershiser, a Mark Prior. It’s hard to screw that up. We get most of our feedback and most of our pride taking a low-end kid and getting a college scholarship or a pro contract on the low level, even if he never gets to the big leagues. Those guys, we’re just as proud of them as the profile people.

Inform, instruct, inspire are the three I’s of our approach.

Thank you for reading

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