How to Stop Flying Open: A Glove-Side Command Drill for High School Pitchers

If your high school pitcher misses high and to his arm side, the fix usually isn't his release point — it's a glove side that flies open early. The Glove-Side Wall Stay-Closed Command Drill uses a wall as honest feedback to keep the front side firm, closed, and aimed at the catcher.

When the glove side flies open, the front shoulder and glove pull off the target before the arm is ready, the throwing arm drags behind, and the ball sails. The cure is a firm, controlled glove side that stays closed and directs the whole body straight at the catcher — and a wall is a brutally honest tool for grooving it.

Why flying open wrecks command

Flying open is one of the most common and most damaging mechanical faults in amateur pitching. When a pitcher pulls his front shoulder and front hip toward his glove side before the throwing arm catches up, the arm drags, the release point climbs, and the ball misses high and arm-side. Former professional pitcher and BetterPitching.com founder Phil Rosengren ties this directly to the glove arm:

"If you don't control your glove, but instead swing it out (towards 1st base for a righty) or let your glove drop as your throw, you will open early and lose the rotational power needed for maximum arm speed." — Phil Rosengren, founder, BetterPitching.com (source)

It isn't only a velocity issue. Rosengren is blunt about what it does to command:

"Not only is flying open an energy leak, it's also a major timing disruptor, which hurts control." — Phil Rosengren, founder, BetterPitching.com (source)

In a separate piece on missing high, he points coaches away from the release point and back to the front side:

"when the glove arm gets sloppy or too aggressive and pulls away from your body, things get out of sync." — Phil Rosengren, founder, BetterPitching.com (source)

The principle underneath all of this is well established at the highest levels of pitching research: the front side, when it stays closed and then firms up, becomes a brace that the torso rotates around. Driveline Baseball describes the lead side as a mechanism that "pulls the back side around in an effective sequencing of body parts," and stresses "how long he kept the front side closed, while still using it to create leverage" (Driveline Baseball). Stay closed longer, brace, and rotate around the brace — that's the command sequence.

The cue that actually works: control your glove

There are a dozen glove cues floating around youth dugouts — "tuck it," "pull it," "swivel it." Rosengren landed on one he found most effective:

"I've found 'control your glove' to be the most effective glove-arm cue, since it puts the emphasis on bracing up with the front side and creating a good pivot for full trunk rotation." — Phil Rosengren, founder, BetterPitching.com (source)

The distinction matters. A violent "glove pull" yanks the front side open; a controlled "glove tuck" into the chest keeps the shoulder closed and stable. Former pro pitcher and coach Dan Blewett makes the same point in his glove-arm breakdown — the glove should swivel and stabilize into position over the front hip, firm but not frozen, so the torso can rotate against it rather than spinning out early (Coach Dan Blewett, YouTube).

How to run the drill

The genius of using a wall is that it removes the argument. A pitcher can't talk his way out of bumping the wall. Set the pitcher in his front-foot-plant position with his glove-side shoulder a few inches off a flat wall — close enough that a real fly-open touches it, far enough not to crowd a normal move. From there:

1. Start balanced over the front foot with the glove extended toward the target.
2. As the torso rotates, tuck the glove firm into the chest — "like flexing a bicep" — rather than swinging it out or dropping it.
3. If the glove-side shoulder drifts back into the wall, that's instant feedback the pitcher opened early.
4. Drive the chest and belt buckle straight down the power line at the target.
5. Check each rep: did the shoulder touch the wall, and did the ball finish at the target or sail high and arm-side?

Run 8–10 controlled reps from a static plant first, then build to a full delivery. For the full step-by-step setup, cues, and progression, see the Glove-Side Wall Stay-Closed Command Drill.

Coaching cues that travel to the mound

Keep the verbal cues short so a 16-year-old can hear them mid-delivery:

• "Control your glove — don't let it fly."
• "Tuck to your chest, don't pull it off your body."
• "Stay closed one beat longer."
• "Chest and buckle straight at the catcher."

Common mistakes

The two opposite errors are both easy to spot here. The first is the glove swing — the lead arm sweeps out toward the glove side, dragging the shoulder open; the wall catches it every time. The second is over-tucking and sticking the glove so tight to the body that the torso can't rotate, killing both velocity and timing. The glove stabilizes firm, it doesn't freeze. Watch also for the pitcher standing so close to the wall he can't make a real move — set the distance so only a genuine fly-open makes contact. Finally, a head that lunges past the front knee pulls the front side open just as surely as a bad glove; keep the eyes level and over the brace.

Where it fits in practice

This is a pre-bullpen primer. Run it during the throwing-day warmup or at the start of a flat-ground/pen block, 1–2 sets of 8–10 reps, before the pitcher moves to located targets. Because it needs only a wall and a glove, it's an ideal at-home assignment between team practices. Progress it by removing the wall and moving to a bullpen with corner targets (low-glove, low-arm): the firm front side the pitcher just grooved should now show up as repeatable command. As Rosengren sums it up, when accuracy matters, the glove arm matters — so the next time a pitcher is missing high, look to his front side.

Sources

• BetterPitching.com — The Importance of Good Glove-Arm Action (Phil Rosengren) — verbatim quotes on controlling the glove, flying open, and the "control your glove" cue.
• BetterPitching.com — Missing High? Look to Your Front Side (Phil Rosengren) — quote on a sloppy/aggressive glove arm getting the delivery out of sync.
• Driveline Baseball — How to Use the Glove Side in Pitching (Kyle Boddy) — front side pulling the back side around and staying closed to create leverage.
• Coach Dan Blewett — Glove Arm Action: What's Its Role in Pitching Mechanics? (YouTube) — swivel-and-stabilize glove-arm demonstration.