The Checkpoint Ladder: A Coach's Guide to Building Infield Throwing Velocity

Ask an infielder how they plan to add velocity across the diamond and you'll usually get one answer: throw harder. The problem is that "harder" without structure just means "earlier"—the arm speeds up to cover for a body that isn't sequencing well, accuracy drifts, and the extra effort quietly runs up the arm-injury tab. The Checkpoint Ladder was built to solve that. It turns velocity into something a player has to earn one link at a time, with a radar gun as the referee.

Why this drill matters

Infield throwing velocity (inf_velo_mph) is one of the most scouted and most trainable defensive numbers there is. It's the difference between beating a fast runner from the hole and being a half-step late, and at showcases it's a headline stat next to pop time and exit velo. But it's also where players most often try to shortcut the mechanics, because a radar gun rewards the single hardest throw regardless of how ugly it was.

The Checkpoint Ladder reframes the goal. Rather than one all-out heave, the athlete climbs four throwing positions—seated, tall-kneel, power position, and full footwork—and can only advance to the next rung after hitting a velocity target at the one they're standing on. That single constraint does something a normal throwing session can't: it tells you exactly which link in the chain is leaking velocity. If a player can't clear the seated (trunk-only) number, no amount of leg drive downstream is going to fix the real problem, and now you both know it.

The mechanics behind the ladder

A throw is a kinetic chain: the ground pushes the legs, the legs turn the hips, the hips whip the trunk, the trunk slings the arm, and the wrist and fingers finish it. Velocity is built by adding these segments in order and transferring energy up the chain without leaks. This proximal-to-distal sequencing is well documented in the pitching and throwing research from the American Sports Medicine Institute (ASMI) and is the same principle Driveline Baseball uses when it builds throwing programs from constrained positions up to full-effort throws.

The four checkpoints map directly onto that chain:

• Seated (trunk only): legs are out of the picture. The player has to create velocity with trunk rotation and a clean arm. Target: ~70% of their standing baseline. This is the honesty test for the top half.
• Tall-kneel (trunk + hips): now the hips can rotate but the legs still can't drive. Target: ~80%. If the number jumps a lot here, the hips are a strength; if it doesn't, hip rotation is a leak.
• Power position (add the legs): standing, front foot planted, loaded on the back leg, no stride. The player drives the back leg into a firm front side. Target: ~90%. This is where leg contribution shows up on the gun.
• Full footwork (the real play): field a ground ball, shuffle into a crow-hop or replace-step, and fire at full intent. Target: meet or beat baseline, chasing 3–4 mph over it.

Because each rung's target is a percentage of that individual player's own baseline, the drill self-scales. A 12U shortstop and a college third baseman run the identical structure with completely different numbers on the gun.

How it fits into practice

This is a focused, radar-on station, not a warmup. Slot it after a full arm-care series and build-up catch play, when arms are hot but fresh. Budget about 20 minutes and cap the athlete at roughly 25–30 max-intent throws for the session—those throws count toward total throwing workload, a point MLB Pitch Smart makes clearly for youth arms. Run it as a station in a defensive circuit: two or three players rotate through, one throwing, one catching or shagging, one reading the gun and logging the best number.

Day one is a baseline day. Before anyone climbs the ladder, record five full-footwork cross-diamond throws and keep the best as the standing baseline. Every checkpoint target for the next few weeks is set off that number. Re-baseline every three to four weeks so the targets keep pace as velocity climbs—stale targets quietly turn a hard drill into an easy one.

A note on the target line: the aim point never changes as you go up the ladder, only how much of the body is allowed to help. That keeps accuracy honest. A radar number that comes with a throw sailing over the first baseman's head isn't a win, and pairing the velocity target with a fixed target enforces that.

How to progress it

Regression. For younger or newer throwers, shorten the distance, widen the target, and knock each checkpoint target down 5–10%. You can also remove the ground-ball read at checkpoint 4 and let them set their own feet, so the last rung is about a clean full-effort throw rather than reacting to a live ball.

Standard. The four rungs as written, targets tied to baseline, two to three full climbs per session with 60–90 seconds of rest between climbs. If a player fails a checkpoint twice, they drop a rung, fix the flagged link, and re-earn it. That failure-and-drop rule is the whole point—it forces the fix instead of papering over it.

Advanced. Turn checkpoint 4 into a pop-clock: the player has to field, transfer, and clear their baseline velocity inside a roughly 1.5-second transfer window, so quick release and velocity are trained together. Feed backhands and slow-rollers as the ground ball so game-real footwork still has to produce the number. This is where the drill starts to look like showcase and game defense rather than a lab throw.

The bottom line

Velocity that shows up on the gun but not in the game is a trap. The Checkpoint Ladder makes players build infield throwing velocity the way the body actually produces it—trunk, then hips, then legs, then footwork—and it uses the radar not as a bragging tool but as a gate. Earn the rung, then climb. What you get is a bigger number that's actually attached to a repeatable, on-line throw.

Sources

• American Sports Medicine Institute (ASMI) — research on proximal-to-distal throwing sequencing and the throwing kinetic chain.
• Driveline Baseball — constraint-based and position-progression throwing methodology and radar-based velocity training.
• MLB Pitch Smart — youth throwing workload and arm-care guidance, including counting high-intent throws toward total workload.
• National Strength and Conditioning Association (NSCA) — principles of progressive overload and rate-of-force development applied to athletic development.