How to Prevent Sign Stealing in Baseball: 9 Fixes, From Tonight's Game to a Permanent Solution (2026)

To prevent sign stealing in baseball, make your signs harder to see, harder to decode and, where the rules allow, invisible. In practice that means hiding the catcher's signs, using a changing indicator or hot sign, rotating wristband cards, cleaning up location tells, and ultimately sending the call to the catcher by one-way earpiece so there is nothing on the field to read.

If you have watched a runner at second touch his helmet and your hitter suddenly sit on the curveball, you know complex sequences only buy time. A sharp runner cracks an indicator in a few pitches; a coaching staff with video cracks a wristband over a tournament weekend. This guide gives you nine fixes in the order you can use them, starting with what works in tonight's game and ending with the one that removes the problem entirely. MAVTRAX is the free app many youth and travel teams use for that last step.

Almost all sign stealing comes from four places: the runner at second, the base coaches, the opposing dugout and video.

• The runner at second looks straight in at the catcher's hand. Once he figures out the pattern, he relays pitch or location to the hitter with a small gesture.
• Base coaches, especially at third, can see a catcher's signs if the catcher's knees open or the glove does not shield them.
• The opposing dugout reads your coach's signs to the catcher, or watches your catcher's location setup.
• Video between games lets a staff decode an indicator or wristband mapping at leisure, then use it next time you play.

Pitchers and catchers also give things away without any signs: a pitcher who flares the glove for a curveball, or a catcher who shifts inside early. Those count as "sign stealing" in the hitter's favor too.

Close the knees, give signs deep against the inside of the right thigh, and use the mitt to shield the view from third.

• Knees narrow in the sign stance, so the base coaches cannot see between them.
• Hand deep in the crotch, not out in front of the cup.
• Mitt over the left knee (for a right-handed catcher), blocking the third-base coach's angle.
• Fingers apart and clear for the pitcher; consider white tape or nail polish at night so the catcher does not need to flash them wide.

Our catcher signs and signals guide has diagrams of the stance and the standard sign vocabulary.

A system where the meaningful sign changes (an indicator, a hot sign, or a count-based rule) is much harder to steal than a fixed "second sign" system. A few proven options:

Indicator. The pitch is the sign right after a specific indicator (for example, the sign after the first "2"). The runner sees five signs and cannot tell which one matters.

Hot sign by inning. The live sign is the first in the first inning, the second in the second, and so on, cycling back. Simple for the battery, annoying for the runner.

Outs plus one. The live sign is outs plus one: nobody out, first sign; one out, second sign; two outs, third sign. It changes during the inning without anyone saying a word.

Pump or add-up. Two or three signs are added together, and the total points to the pitch (for example, 1 = fastball, 2 = curve, 3 = change, 4 = back to fastball). Harder to read, but slower and more error-prone for young catchers.

Decoys. Mix in signs that mean nothing, and vary the number of signs every time so the runner cannot count.

Whatever you choose, switch to it the moment a runner reaches second, and practice it at practice. A clever system your catcher fumbles is worse than a simple one run cleanly.

Wristband cards move the secret from the finger to the card: the catcher (or coach) calls a number, and the pitcher and catcher look it up on matching cards. Because the number means nothing without the card, the runner has nothing obvious to read.

• Use several cards (A, B, C) with different mappings and switch by inning or after any suspicious at-bat.
• Use decoy digits so the same pitch appears under several numbers.
• Print large and laminate. Cards must be readable in a crouch, in bright sun.

Ready-made pitch-calling wristbands cost a few dollars and up. The limits: the catcher looks down at the wrist on every pitch, and a patient opponent with video can still build the mapping over a series. Rotation is what keeps cards safe.

Set up late. A catcher who slides inside before the pitcher starts the delivery tells the runner, the base coaches and sometimes the hitter where the pitch is going. Teach the catcher to give the sign from the middle, stay there, and move to the target as the pitcher's hands separate. Sit still and quiet; no loud shifting of the feet. Pitchers should also hide grips in the glove and keep the glove the same shape for every pitch, which also helps against hitters who read tips. Our catcher pitch framing guide covers late setups and quiet targets.

5. Change the system mid-game. Have a second sequence ready. If a runner at second starts touching his helmet before pitches, switch immediately.

6. Watch the runner. Assign a player in the dugout to watch the runner at second for any gesture timed with your signs. You will often spot the relay before you spot the damage.

7. Protect the dugout-to-catcher step. If you call from the dugout, stand where the other bench cannot see you clearly, use a changing indicator, or use a wristband number instead of a sequence.

8. Use the mound visit wisely. If you think the code is blown, a single visit to change the system is worth more than several pitches thrown under a leak. Check your league's mound-visit limits.

All of these help. None of them is permanent, because every visible sign can eventually be read. That is why the last fix matters.

Because nothing is visible. The coach taps the pitch and location on a phone, and the catcher hears "Curveball, down and away" through a speaker inside the helmet. There is no finger to read, no sequence to crack, no number to map. The catcher gives the pitcher one simple sign (the secret part already arrived privately) and play goes on.

It is allowed at many levels: NFHS high school baseball has permitted a one-way device from a coach in the dugout to the catcher since 2024, NFHS softball since 2025, and Little League since 2025. Travel events set their own policies. Check your league's current rules.

Setup:

1. Get MAVTRAX free on iPhone, Android or the web. No subscription, no card.
2. Mount a helmet-mount Bluetooth headset inside the catcher's helmet over one ear. Our pick is the ELIKIDSTO IPX7 helmet headset at about $13. Avoid earbuds and headbands; they come off with the helmet. Install guide: mounting a headset in a catcher's helmet.
3. Pair, test from your dugout, and call the game. Every pitch is logged by pitcher.

For how the dedicated hardware alternative works, see how electronic pitch-calling hardware works; for the full category, the electronic pitch calling systems guide.

Reading signs with your eyes is generally treated as part of the game; using technology to steal them is not.

• Usually legal: a runner at second watching the catcher and relaying with a gesture. It has been part of baseball for more than a century.
• Prohibited: using cameras, video feeds or electronic devices to decode and relay signs during a game. MLB disciplined the 2017 Houston Astros for using a camera feed and banging on a trash can to tip pitches to hitters.
• Youth and amateur rules: many organizations restrict electronic devices and some address base-runner signaling or sportsmanship directly. Check your league's rulebook and any local rules.

For youth coaches, the productive response is to remove the vulnerability rather than argue about it.