Twenty one working references for reading a delivery: what to look for, the anatomy and physics underneath it, what actually changes it — and the cases where the thing you were about to fix is the reason he gets outs. Read online or download the PDF.
The full body part by body part diagnostic, ground up through all seventeen links of the kinetic chain.
Covers: reference values in plain English · muscles and how they contract by phase · what to screen and what to load · motor preference · the force velocity programming layer · and an adaptation ledger for when a compensation is worth keeping.
Hips, then chest, then arm, then hand. Each peaking later and faster than the last, and each slowing down to pass its speed forward.
Covers: the order and the speeds · the two ways it breaks · why skilled pitching is better organised variability rather than less of it · and why efficiency and output are different axes.
One screening battery that feeds every other document here. Twenty minutes on a table and a floor, answering one question at each joint: can he, or can he not.
Covers: the full battery in delivery order · what each test rules in or out · three questions that replace tests · what to film and which frames matter · and what you can measure without a lab.
Two athletes can throw the same velocity with deliveries that share almost nothing, because they are running different engines. One rebounds off the ground. The other sinks into it and pushes.
Covers: aerial and terrestrial phase by phase · the other three axes · six common instructions and who they are wrong for · how to read it without pretending it is a test · four things it does not excuse · and where the evidence actually stands.
There is one interface between a pitcher and everything he is trying to do, and it is about the size of a shoe. Lose it early, point it the wrong way, or get the body ahead of it, and nothing above the ankle recovers what was never produced.
Covers: force, time and direction as three separate losses · nineteen ways the connection goes, grouped · the pushy pelvis · eight video tells · the screen that starts with the ankle · the fix in five stages · and when a short drive phase is the engine rather than a leak.
Third base for a right hander, first base for a left hander. The pelvis slides toward the throwing arm side instead of travelling down the line to the plate, and every bit of force that goes sideways is force the delivery does not get.
Covers: the same leak in both hands · why the correction costs more than the leak · thirteen causes grouped · eight video tells, all from behind · the frontal plane screen · the fix in five stages · and when lateral movement is the design rather than the fault.
Hiking the hip produces tension, and tension feels like loading. But the tissue under tension has no line of pull into the pitch.
Covers: what loading actually means · shift versus lift · the one question field test · why the feeling is so convincing · where the bill lands · and when a hike is not a fault.
A front hip with no rotational range cannot be an axle, so the lead leg swings the pelvis open instead of anchoring it, and the back leg gets pulled through early.
Covers: the four decisive frames side by side · the failure cascade in order · eight video tells · screens that separate cannot from does not · and when the picture has a different cause.
Landing turned out does not make the block impossible. It makes it expensive, and whether he can afford it comes down to how fast he produces force.
Covers: the contact to release time budget · stacked versus bowed geometry · a landing position and rate of force development matrix · and why get stronger is the right idea and the wrong measurement.
Hip to shoulder separation is the most chased number in pitching and one of the least supported. The same figure can mean two opposite things depending on which segment produced it.
Covers: what the evidence actually says · earned, leaked and borrowed separation · why timing beats magnitude · where separation actually comes from · and the case for lowering the number on purpose.
When the chest arrives square at foot contact, the delivery has spent its rotation before the part that needed it, and the arm has nowhere left to be carried through.
Covers: the one frame that decides it · eight causes, only two of them at the chest · the cost cascade in order · the fix in sequence · and when an early chest is not the problem.
Layback is not something a pitcher does. It is what happens to a relaxed, well positioned arm when a fast trunk rotates underneath it.
Covers: the composite that makes up the number · what trap, serratus and nine other muscles do to your range · forty two reasons layback comes up short, grouped · fake layback · and when short layback is the right answer.
A pushing arm is not a style or a habit. It is what an arm does when the body underneath it fails to carry it, and four of the seven causes come from the training rather than the athlete.
Covers: carried versus generated · the seven causes grouped by who created them · what pushing costs at both ends of the motion · the fix in order · and two things pushing is not.
Acceleration gets all the training and deceleration does all the failing. Over 225 pounds of pull tries to separate the arm from the shoulder on every pitch.
Covers: the forces, per pitch · the six muscles doing the stopping · six faults that shorten the runway · why late innings are a different exposure · and how to train catching force rather than producing it.
You cannot throw your way to a lower elbow bill. Asking for less effort barely moves the load, and the seven levers that do move it are all positions and timings.
Covers: why reduced effort does not work · the seven published levers · the bad trade and the worst profile · what size adjusted actually means · and why forearm work is armour rather than a fix.
A throwing shoulder is not a normal shoulder and is not supposed to be. One measurement separates bone that adapted from tissue that shortened, and most people take the wrong one.
Covers: what actually changes in a throwing arm · total rotational motion versus the number usually taken · what a real restriction does downstream · and what to do for each finding.
Velocity falls about a quarter mph an inning while elbow load climbs after the third. He is throwing softer and paying more at the moment he feels least dangerous.
Covers: the order things fail in · why load rises while output falls · why rate goes before strength · why asking how he feels does not work · and what to watch for without a lab.
Command is decided at foot contact, not at release, and the variability people try to drill out of the arm is the mechanism that saves pitches that started wrong.
Covers: the funnel model · the two positions worth making consistent · six things not to chase · why velocity buys margin · and how to train the entry rather than the exit.
Release height, side, extension and spin axis. Every mechanical change in this library is only worth what it does to those four, because they are what the hitter actually sees.
Covers: what each of the four does · which mechanics set which number · three trades nobody prices · reading it backwards from the shape you want · and what to measure.
The league is going low and the data supports it. But the same change produces the opposite kinetic result in high school pitchers, and one wrist measurement decides whether it works at all.
Covers: what dropping the slot actually bought · the wrist range that gates it · the population flip · who is a candidate and who is not · and why raising a slot is a different conversation.
A hitter has to start swinging before the ball is released, using your body as the clock. Tempo changes what that clock says without changing anything about the pitch.
Covers: delivery tempo versus time to plate · why the hitter is vulnerable to it · what each end costs · tempo as a built in preference · and six ways to use it deliberately.
Reference values throughout are population means with real spread — they locate an athlete, they don't grade one. Where a coaching source and a peer reviewed finding disagree, both are shown rather than reconciled. Every claim is sourced in the final section of each document.