The Checkpoint Ladder: How to Build Infield Throwing Accuracy That Holds Up

Ask a room of coaches how they train throwing accuracy and most will describe volume: more reps, more long toss, more ground balls to first. Volume builds an arm, but it does not guarantee the ball goes where the receiver can catch it. Accuracy is a *skill under difficulty*, and the fastest way to lose it is to add difficulty faster than the athlete has earned. The Checkpoint Ladder is built to stop that from happening.

The idea is simple. You set a target the size of a teammate's chest and glove, and you make the athlete prove they can hit it - 8 of 10 throws inside the zone - before they unlock the next, harder rung. No clearing the gate, no advancing. It treats accuracy the way a video game treats a level: you replay the checkpoint until you beat it, and only then does the next challenge open up.

Why a gated progression beats open reps

The measurable outcome here is throw_accuracy_pct - the share of throws that land in the target zone. When you track that number rung by rung, two things become obvious. First, most players' accuracy falls off a cliff the moment you add footwork, distance, or a fielded ground ball. A player who hits 9 of 10 from set feet at 60 feet might hit 4 of 10 off a ground ball at 120 feet. That gap is the coaching target, and open, unscored reps hide it completely.

Second, gating protects the skill. Motor-learning principles and the player-development work popularized by groups like Driveline Baseball emphasize that practice difficulty should be challenging but *representative and attainable* - the athlete should succeed often enough to encode the right movement pattern. When you let a 12-year-old fire max-effort throws across a full diamond before they can hit a chest at 60 feet, you are rehearsing the miss. The checkpoint keeps every rep close to a success the athlete can actually repeat.

The mechanics the ladder is really training

Throwing accuracy is not a mysterious talent. It is the product of a few repeatable checkpoints inside the throw itself:

• A clean transfer to a four-seam grip. A ball gripped across the seams flies straight; a two-seam or off-center grip tails. Rushing the transfer off a ground ball is the single biggest accuracy leak for infielders.
• Lining up the front side. The glove-side foot and the throwing shoulder should point at the target before release. If the front side flies open early, the ball sails arm-side; if it stays closed, the ball pulls glove-side.
• A consistent release point. Dropping to a low three-quarter or side-arm slot under fatigue makes the ball run and sink unpredictably. A repeatable, higher slot is more forgiving.
• Momentum through the target. Firm throws with the chest finishing over the front knee are more accurate than arm-only flips. The crow-hop rung exists to teach the athlete to move *toward* the zone.

The ladder isolates these one difficulty at a time. Rung 1 removes footwork so the athlete can feel the grip and release. Rung 2 adds momentum. Rung 3 adds the fielding action and the transfer clock. Rung 4 adds moving-throw chaos. Because the target never changes, the athlete always knows what "good" means.

How it fits into practice

The Checkpoint Ladder is a 15-20 minute block that fits cleanly into an infield or throwing day, and it works for baseball and softball alike. A few ways coaches use it:

• As a scored station. Run three or four players through parallel ladders with their own targets and tally sheets. The scoring makes it self-competitive without a coach hovering.
• As a warm-up standard. Have each athlete re-start one rung below their best clear from last session, then try to advance. This creates a visible progression athletes can chase week to week.
• As an assessment. Once a month, record the top rung each player clears and their accuracy at it. That is a clean, comparable data point - far more useful than "his arm looks good."

Crucially, the drill is honest. If a player cannot advance past Rung 2, you have not failed - you have found exactly where their accuracy breaks, which is the whole reason to run it.

Coaching the scoring so the number means something

The ladder only works if the accuracy number is trustworthy, and the most common way it gets corrupted is a helpful partner. If your receiver reaches out and catches an off-target throw, that throw looks like a make and gets scored like one. Then you advance a player who has not earned it. Coach your receivers to hold the glove still at chest height and let bad throws miss. A live partner is fine, but a fixed net with a taped zone removes the temptation entirely.

Similarly, resist "close enough." A throw that would pull a first baseman off the bag is not a make. Draw the zone at the size of a chest and glove and hold the line. The discipline of honest scoring is what turns a fun game into real feedback.

Progressing without breaking arms

Because this drill has a moderate throwing volume - and can climb higher when players repeat rungs - workload matters. Follow the spirit of MLB and USA Baseball's Pitch Smart guidelines and the arm-health research from the American Sports Medicine Institute (ASMI): count throws, respect age-appropriate limits, and never run high-volume, high-intent throwing on a cold or fatigued arm. Warm up with band activation and a build-up catch-play progression first. Keep the early rungs firm-and-controlled rather than max effort; save intent for after the accuracy gate is cleared.

When a player owns all four rungs, do not just add distance. Shrink the target from roughly 30 inches to 20 inches, add a specific glove location (a tag spot rather than a square), or layer a stopwatch on the fielding rungs so accuracy has to survive a real transfer clock. Each of these raises difficulty while keeping the checkpoint logic intact: prove it, then progress.

The takeaway

Accuracy is not built by hoping it survives more reps. It is built by defining a clear target, scoring honestly, and refusing to let difficulty outrun skill. The Checkpoint Ladder gives coaches a simple, repeatable structure to do exactly that - and a single number, throw_accuracy_pct, to prove it is working.

Sources

• Driveline Baseball - player-development and throwing-skill acquisition principles (representative, appropriately difficult practice).
• American Sports Medicine Institute (ASMI) - youth throwing arm-health and workload research.
• MLB / USA Baseball Pitch Smart - age-based throwing workload and recovery guidelines.
• National Strength and Conditioning Association (NSCA) - youth training and progression principles.