Checkpoint-Ladder Infield Velocity Progression: A Coach's Guide to Building Real Arm Speed

Why this drill matters

Ask a young infielder to throw harder and you will almost always see the same thing: a longer arm swing, a bigger lean back, and a ball that leaves the hand from a slightly different, slightly worse position every time. Velocity might tick up for a throw or two, but it is noisy, it is inconsistent on the radar, and it often comes with a whippier, higher-stress arm action. That is the problem the Checkpoint-Ladder progression is built to solve.

Infield velocity (tracked in the A-City drill library as inf_velo_mph) is one of the most-evaluated tools a middle infielder or corner has, especially at showcases and tryouts where a radar gun is sitting behind the bag. But a gun reading is only useful if it comes from a repeatable throw. The premise of this drill is simple: if the throwing position is identical on every single rep, then any velocity you add can be traced to a specific segment of the throw — the torso, the stride, the hips, the crow-hop — rather than to random extra effort. You build the number honestly, and you build it on top of a clean, low-stress arm action instead of in spite of a messy one.

The mechanics behind it

The whole drill is organized around one position that coaches variously call the checkpoint, the loaded position, the power position, or high-cock: throwing elbow roughly at shoulder height, forearm vertical, the ball facing away from the target, chest closed, and the glove elbow pointing where you want to throw. This is the position the arm should pass through just before it accelerates forward, and it is the position sequencing-based throwing programs (Driveline Baseball's work on throwing being a chain of segments, for example) treat as the hinge of the delivery.

A hard, efficient throw is a kinetic chain: energy is created from the ground, passed up through the legs and hips, into the trunk, and finally released through the arm and wrist, with each segment peaking and handing off to the next. The reason "just throw harder" fails is that it usually means firing the arm early, before the lower half has done its job. When the arm leads, you cap how much of the chain contributes and you shift load onto the shoulder and elbow.

The Checkpoint-Ladder rebuilds that chain from the top down. You begin with the arm-only throw so the athlete owns the release position first. Then you add the trunk, then the stride, then the hips, and finally a crow-hop — each stage feeding more of the lower body into a throwing position that never changes. Because you are adding one link at a time, the athlete feels exactly what each segment contributes, and the radar confirms it.

Why gate each stage with the radar

The feature that makes this a progression and not just a warmup is the gate. An athlete only advances from, say, Stage 2 to Stage 3 after they beat the previous stage's peak by a couple of miles per hour on a few reps AND hold a clean checkpoint while doing it. This does two things.

First, it keeps mechanics honest. Velocity is a wonderfully objective referee. If adding the stride does not add velocity, either the stride is not connected to the throw or the athlete broke the checkpoint to force it — and the number tells you before you have grooved a bad rep a hundred times. Second, it makes the drill self-motivating. Players will happily chase the next rung when the rung is clearly defined and the gun is the judge. You are turning a mechanics drill into a game with a scoreboard, which is exactly what keeps a 14-year-old locked in for 25 focused minutes.

A quick note on numbers: the 2-mph-per-stage bumps and the 6-mph overall target in the success criteria are coaching defaults, not laws of physics. Bigger, stronger, more advanced arms will jump more between stages; younger athletes will see smaller, choppier gains. Re-baseline the arm-only Stage 1 every couple of weeks and let the whole ladder float up together.

How it fits into practice

This is a throwing-day drill, and where you place it matters. Run it after a full dynamic warmup and a progressive catch-play build-up, when the arm is warm but not fatigued — never as the last thing before you go home with a tired arm, and never on a day the athlete threw a bullpen or a heavy long-toss session. In a team setting, pair athletes up on a line with a shared gun rotating down the group; each pair logs peaks on a whiteboard so you can see who is stuck on which rung.

In the A-City practice flow it slots naturally into an off-season or pre-showcase fielding block, and it earns its place next to arm-care work rather than replacing it. Sequencing wins the early, "free" velocity — the gains from simply throwing from a better position in a better order. Actual arm strength, mobility, and total throwing volume raise the ceiling over months. Treat this drill as the mechanics half of that equation.

Because it is a max-intent progression, respect workload. Cap total high-effort throws, keep it to a couple of sessions a week with rest between, and follow age-appropriate throwing and rest guidance. MLB Pitch Smart's workload and recovery framework is written for pitchers, but the underlying principle — that hard throwing is a stress that needs monitoring and rest — applies to position players hunting velocity too.

How to progress it over a block

Early in a training block, keep athletes living in Stages 1 through 3. A clean checkpoint and a repeatable stride are the foundation; there is no hurry to add hips and a crow-hop on top of a shaky base. As gates are cleared over the following weeks, unlock Stages 4 and 5. Every couple of weeks, re-test the Stage 1 arm-only baseline — if that bottom rung has risen, the athlete has genuinely gotten stronger and more efficient from the checkpoint, and every stage above it will rise with it.

Once the full ladder is clean from a set position, add game context: run the crow-hop finisher off backhands, off balls fielded on the move, and from different infield angles, so the checkpoint holds up under the footwork chaos of a real play. That is the bridge from a controlled velocity number to velocity you can actually use at short or third.

The single measurable that tells you the drill worked is right in the success criteria: the athlete's logged crow-hop peak should clear their arm-only baseline by a meaningful margin — a default of about 6 mph — while every stage in between stays mechanically clean. When that happens, you have not just measured a harder throw. You have built one, segment by segment, on a foundation you can trust.

Sources

• Driveline Baseball — research and coaching material on throwing as a sequenced kinetic chain and on velocity development.
• American Sports Medicine Institute (ASMI) — biomechanics of the overhand throw and throwing-arm injury research.
• MLB Pitch Smart — throwing workload, rest, and recovery guidelines for youth arms.
• National Strength and Conditioning Association (NSCA) — principles of the kinetic chain and power development transferring to athletic throwing.