This guide mirrors exactly how to evaluate a throw: start with the overlay video, then walk page‑by‑page through the PDF, then interpret phases and patterns, and finally choose what to work on. It’s written so you can open your own report and follow along.
Pre‑Check: Make Sure the Overlay Is Optimal
- Record with good background contrast (avoid blinding backlight or very dark scenes).
- Don’t over‑trim the video at the start/end or let video run too long at the end; include the full throw and a clean finish.
- If tracking looks off, try a better capture; if it persists, file a support ticket. Tech is robust, but like any first‑of‑kind system, occasional recalibration helps.
Step 1 — Overlay Video Review (Your Visual Report)
Posture at Key Phases
- From foot strike through ball release, keep the chest stacked over the hips.
- Avoid early forward flexion or a collapsed back leg (knees caving in) at foot strike.
Arm Tracer Path
- Might be small inaccuracies in the first ~¼ of the throw (ball can occlude tracking of the wrist); last ~¾ should always be clean.
- From layback → release, the slot should stay level. A big rise/drop suggests a changing slot.
- In the pull phase, the slot can start lower and settle to level, but never start high (elbow above shoulder).
Peak Arm Speed (red marker in the tracer)
- Ideal: peaks right at or just before ball release (acceleration through release).
- If peak occurs early, a common cause is strength limitation—the body slows itself to protect the arm/shoulder.
Sequencing Bar + Timeline (bottom)
- Desired order: 1) foot strike → 2) peak hip speed → 3) peak torso speed → 4) peak elbow extension velocity.
- Two common issues to watch for:
- Hips slow to rotate after foot strike (pushing/sliding, not rotating).
- Peaks stacked too close together (little/no delay between hips and torso).
Right‑Side Metric Tiles (quick snapshot)
- Max shoulder external rotation (MER)
- Peak arm speed
- Peak hip–shoulder separation velocity
- Release time
Step 2 — PDF Page 1 (Still Frames + 4 Key Metrics)
Still Frames (4 images)
- Foot strike, back hip termination, torso termination, maximum elbow extension.
- Use these clean frames (without markers) to verify: posture, base width, and weight shift.
Four Key Metrics
- Peak Arm Speed (mph) — more potential ball velocity when higher.
- Peak Hip Rotation Speed (°/s) and Peak Torso Rotation Speed (°/s) — check each alone and their sum (overall rotation speed) to gauge body‑driven power.
- Release Time (ms) — practical cutoffs:
- < 400 ms → very elite (closer to ~390 is better)
- 400–500 ms → gray area (closer to 500 = long)
- > 500 ms → long, needs attention
Compare Speeds Together
- High rotation speeds + low arm speed → energy not offloading to the arm (mechanical transfer issue or strength gap).
- High arm speed + low rotation speeds → arm is the workhorse → increased stress/injury risk.
Color Bars Under Tiles
- Every tile uses a red / yellow / green band for context (lower / mid / upper third).
- Green is generally “good” for that metric (useful anchor for all speeds/tiles in the report).
Step 3 — PDF Page 2 (Sequencing + Scores + Additional Metrics)
Sequencing Graph (velocity y‑axis, reference lines at foot strike / MER / release)
- Confirm order and spacing of peak hip, peak torso, and peak elbow extension events.
- A small but distinct gap from hips → torso → arm indicates efficient transfer.
- Red flags: hips rotate late after foot strike; peaks stacked together.
Scores
- Sequencing Score — how effectively you move power from the ground up.
- Overall Throw Score — a general view of how optimized your current throwing motion is.
- Not a QB ranking; compare you vs. you over time.
- Acceleration Score — how effectively you build speed in the motion.
- Deceleration Score — how well you control and finish the motion.
- Velocity Efficiency Score — how your speed generation and control work together.
Additional Page‑2 Metrics
- Max Shoulder External Rotation (MER, °) — QBs typically optimize around 130–140°; <120° often signals mobility limitation.
- Peak Hip–Shoulder Separation Velocity (°/s) — higher is a better elastic “whip” indicator.
- Stride Length (% of height) — base sized to generate force without getting so wide that you leak energy (it’s relative to height, not just “how far you step”). Example, 48% means base is 48% of your height.
Step 4 — PDF Page 3 (Joint Angles in Degrees)
All angle graphs share the same reference lines: foot strike, MER, ball release.
Throwing Arm Angles
- Elbow Extension → Rise = flexion (more bend), Fall = extension (straightening).
- Shoulder Horizontal Abduction (scap load) → Rise = loading behind the body, Fall = moving across the body.
- Shoulder Abduction (arm slot proxy) → Rise = arm farther from body (higher slot), Fall = arm closer (lower slot).
- A level slot often lives around ~90–110°.
- Shoulder External Rotation → Rise = laying back (external rotation), Fall = coming forward (internal rotation).
Trunk & Legs Angles
- Trunk Flexion → Rise = forward flexion, Fall = extension (leaning back).
- At MER, look for negative (extension) to confirm thoracic extension during layback.
- Trunk Rotation → Rise = rotating toward target, Fall = rotating away.
- Pelvis Rotation → Rise = hips toward target, Fall = away.
- Hip–Shoulder Separation (°) → Rise = the gap increases, Fall = the gap closes;
- Positive = hips ahead of shoulders; Negative = shoulders ahead of hips.
- Ideal: create a large positive gap early, then be near zero by ball release.
- Lead Knee Flexion → Rise = more bend, Fall = more extension.
- Evaluate delta from foot strike → ball release: ~10° = fine; 10–15° = okay; ~20°+ = excessive extension trend.
- Also check absolute at ball release — near 0° (locked out) is a major red flag.
Step 5 — PDF Page 4 (Joint Velocities in °/s)
How to read velocity graphs:
- These lines show how fast joints are moving; direction alone (up vs. down) doesn’t tell the whole story.
- Always pair Page 4 with Page 3: first see what motion is happening (angles), then check how fast it’s happening (velocities).
- Focus on timing and magnitude: when a joint speeds up or slows down, and whether that happens at the right moment in the throw.
Throwing Arm Velocities
- In MER → ball release (acceleration phase), identify which actions truly drive your speed:
- Elbow extension velocity
- Shoulder internal rotation velocity
- Shoulder horizontal adduction velocity
- If you only check one velocity area, make it this throwing arm acceleration window.
Trunk & Legs Velocities
- Review trunk rotation, pelvis rotation, trunk flexion, lead knee, and hip–shoulder separation velocities for when lower body and trunk contribute and stabilize.
- Again, decode with Page 3 positions; use Page 4 to judge velocity vs positioning and timing.
Step 6 — PDF Page 5 (Tabular Data: Exact Angles by Phase + Min/Max Velocities)
Angles reported at: pre‑throw, foot plant, MER, ball release, follow‑through.
Min/Max velocities listed for the same joints.
If you’re overwhelmed, focus on these anchor numbers first:
- Lead foot turnout — at foot plant, MER, ball release.
- 0 degrees corresponds to toes pointed at a camera, 90 to toes at target
- Elbow extension at ball release — confirms full extension.
- Shoulder external rotation at MER — confirms layback.
- Trunk flexion at MER — check for thoracic extension (shouldn’t be forward‑flexed).
- Lead knee flexion — at foot plant, MER, ball release (delta and absolute at release).
Step 7 — PDF Page 6 (Stride Mechanics + Timing/Speed + Scores Recap)
Stride Step Mechanics
- Length (inches) and Length (% of height) — a relative base measure matters most (not just “how far you stepped”).
- Time of stride step (ms) — how long it takes to plant.
Timing & Speed
- Hip–Torso Peak Timing (ms) — time gap between peak hip and peak torso speed.
- Too small → peaks are stacked (poor transfer).
- Too large → energy leaks before it gets to the torso.
- Aim for a small but clear gap.
Scores Recap
- Same tiles you saw on Page 2 (useful to view alongside stride/timing).
Step 8 — Motion Phases (What to Look For in Your Data)
Pull Phase (hand separation → start of steady rise in shoulder external rotation)
- On Page 3, mark the start when elbow extension starts (or shoulder abduction/external rotation lines begin moving).
- Mark the end when shoulder external rotation begins its steady increase.
- What to check:
- Scap load should build (shoulder horizontal abduction rising).
- Shoulder rotation context:
- Internal rotation here is very powerful but lengthens the motion—ensure overall release time stays in a healthy window.
- External rotation here is quick but often costs velocity later—consider nudging toward neutral if speeds/sequence suffer.
- Avoid being too long (over‑extended elbow behind body) or too tight (excessive elbow flexion).
- Abduct the arm away from the body; don’t stay pinned.
Layback Phase (end of pull → MER)
- Confirm a smooth rise in layback without jerks; posture stable; hip–shoulder separation maintained or increased before acceleration.
Acceleration Phase (MER → ball release)
- Peaks should occur in the correct order at strong magnitudes.
- Lead leg should stabilize (avoid racing toward lockout).
- Full elbow extension at release.
- Peak arm speed should be at/near release (early peaks often signal strength gaps).
Step 9 — Big Buckets (Diagnose Your Primary Focus)
Mobility
- Low MER (often <120°) and/or lack of thoracic extension at MER.
- Work shoulder/T‑spine mobility.
Stretch (Elastic Energy)
- Trio: hip–shoulder separation, scap load, MER.
- Most common limitations are scap control and hip–shoulder separation feel (motor patterning).
- Train the pattern (feel), then load it with speed and strength.
Speed
- Low hip, torso, or arm velocities.
- Improve explosive rotation and refine mechanics to raise peak speeds.
Frontside Stability
- Lead knee extension delta from foot strike → release: ~10° fine, 10–15° okay, ~20°+ excessive.
- Absolute at release near 0° (locked) is a major red flag.
- Avoid excessive forward flexion at release; maintain posture to finish with extension.
Strength
- Good sequencing and mobility but speeds remain low → strengthen into the exact positions/ranges you need to access at full speed (throw‑specific strength).
Step 10 — Common Pattern Interpretations (Quick Reference)
- Overall Rotation Speed = hip speed + torso speed
- Higher total → higher velocity potential.
- High rotation speeds + low arm speed → offload/transfer issue or strength limitation.
- High arm speed + low rotation speeds → arm is overworking → stress risk; improve body rotation & sequence.
- High hip speed + low torso speed → usually a hip–shoulder separation maintenance issue (often frontside opening early); occasionally upper‑body rotational strength.
- Early peak arm speed → often strength: the system slows early to protect the arm.
- Low stretch metrics (hip–shoulder separation, scap load, layback) → usually scap control and patterning gaps more than raw ROM.
Step 11 — Action Plan (What to Do Next)
Use Your Recommended Drills
- Go to Drill Library → Recommended (AI‑matched to your metrics).
- Choose 2–4 drills that target your biggest bucket.
Retest Cadence
- As often as every few days or every few weeks, depending on your schedule, training load, and personal factors.
Track Progress with Anchor Metrics
- Arm speed, hip speed, torso speed, MER, hip–shoulder separation velocity, release time.
- Also watch your Page‑5 anchors (lead foot turnout; elbow extension at release; trunk flexion at MER; lead knee flexion across phases).
Get Expert Help
- Book a Coaching Call to review your report, align drills to your goals, and fine‑tune technique.
