By BK, Athletic Hitting Development
Complete Hitters Are Built… Not Given. Earned!
Key takeaways for hitters
- Some hitters build a new move in 500 reps. Some need 10,000 or 20,000. Both can get the same result.
- Reps build habits by changing your nervous system. Practice drives new myelin, the insulation that makes signals faster and more reliable.
- In one human study, the slower learners showed the biggest brain changes. Slow isn’t behind.
- Your body builds whatever you repeat, good or bad. Prove the rep before you repeat it.
- “Want to” is a skill. You can train it like a swing.
Are you a 500 or are you a 10,000?
Some hitters own a new move in 500 reps and some need 10,000 or 20,000, but both can get the same result. Reps build the wiring, slow isn’t behind, and the rep has to be proven on video and ball flight before you repeat it.
Train it: Swing Structure & Mechanics Masterclass →Some hitters see a new move once, feel it, and own it in a few hundred swings. Others need 10,000. Some need 20,000. I’ve coached all three kinds in 52 years of playing, coaching and scouting.
Here’s the part most people miss: either way, you can get the same result. It just might take longer, with more focused and more obsessive work.
1. The 500 and the 10,000
Two hitters walk into the cage with the same problem. Maybe it’s a late load. Maybe they’re casting the barrel.
The first one gets it in a week. The second one is still fighting it a month later. Same coach, same cue, same drill.
The second hitter usually decides he’s just not as good. That’s the wrong conclusion. He isn’t worse. He’s a 10,000, and a 10,000 has to put in more reps. That’s all.
SAME PROBLEM. SAME CUE.
500 OR10,000?
- Some own it in 500 reps.
- Some need 10,000.
- Some need 20,000.
- Same result.
HE ISN'T WORSE. HE'S A 10,000.
2. The science: why reps rewire you
This is a rabbit hole if you’re a biology nerd. I am. Here’s the short version.
Every movement you make runs on signals traveling along nerve fibers. Many of those fibers are wrapped in myelin, a fatty insulation. The better the insulation, the faster and more reliably the signal travels. Fast and reliable is what a swing needs.
Practice changes that wiring. In 2014, researchers at University College London showed that mice had to make new myelin to learn a new motor skill. Mice that couldn’t make new myelin couldn’t learn it. Once the skill was learned, they kept it. (UCL)
In people, a 2016 study had adults practice a new skill with 10,000 arm movements. Brain scans showed myelin increasing in the areas that ran the skill. (PubMed)
“Muscle memory” doesn’t live in your muscles. It lives in your wiring. Reps build the wiring.
Is 10,000 a magic number? No. Nobody can count your exact number. But it’s a good picture of what it takes to turn a new move into a reaction you don’t have to think about.
3. Slow is not behind
Here’s my favorite part of that 2016 study. The people who learned the skill more slowly showed the bigger myelin changes.
Read that again if you’re a 10,000. The extra reps aren’t wasted. Your brain is building more.
I’ve watched plenty of 10,000s pass the 500s. The 500 gets it fast and stops grinding. The 10,000 keeps showing up. A year later, the 10,000 owns the move under pressure, and the 500 is still searching when the game speeds up.
4. Bad reps build habits too
Your nervous system doesn’t care if a rep is good or bad. It builds whatever you repeat.
Ten thousand casting swings build a great casting swing. That’s why quantity alone isn’t the answer. It has to be the right rep, repeated.
And remember: feel isn’t real. A rep can feel right and be wrong. So before you stack thousands of them, prove the rep:
- Film it. Side view and from behind. Check it against the model.
- Read the ball flight. Ball flight tells the truth.
- One thing at a time. One cue. Not five.
- Build it in order. FEEL → REPEAT → SPEED → VARY → DECIDE → COMPETE. Don’t jump to game speed with a move you can’t repeat slow.
BAD REPS BUILD HABITS TOO
PROVE THEREP.
- Film it.
- Read the ball flight.
- One cue. Not five.
- Build it in order.
YOUR BODY BUILDS WHATEVER YOU REPEAT.
5. What 20,000 reps really takes
Here’s the math. These are quality swings with full focus, not mindless ones.
| Goal | 50 swings a day | 100 swings a day |
|---|---|---|
| 500 reps | 10 days | 5 days |
| 10,000 reps | 200 days | 100 days |
| 20,000 reps | 400 days | 200 days |
So the real question isn’t “Am I a 500 or a 10,000?” You won’t know until you’re in it.
The real question: what are you willing to give up if it takes 20,000?
Some video game time. Some Saturday mornings. Some nights when your friends are out and you’re in the garage with a tee. It’s tough. Yes. That’s why it’s worth something.
6. “Want to” is a skill
People talk about “want to” like you’re born with it or you’re not. I don’t believe that.
“Want to” is a skill. You build it the same way you build a swing, one rep at a time:
1. Make it small
Fifty focused swings beats two hundred sloppy ones. Small days you actually do beat big plans you skip.
2. Track it
Count your reps. Write them down. Watching the number grow builds the habit of showing up.
3. Prove it
Film once a week. When you see the move change, the “want to” grows. Evidence builds belief.
4. Earn it
Nobody can give you 10,000 reps. You earn every one of them. That’s what makes it yours.
That’s how every AHD course is built. One focused lesson a day, one cue, a set number of reps, and a way to track and prove the work. Start with SwingChecker™ to find your #1 priority for free, then train it every day in the AHD courses.
THELESSON.
- Slow isn't behind.
- Prove the rep first.
- Make it small.
- Track it.
- Prove it.
- Earn it.
Complete Hitters Are Built…Earned.
Quick answers
How many reps does it take to build muscle memory in a baseball or softball swing?
There is no single number. Some hitters own a new move in a few hundred quality reps; others need 10,000 or more. What matters is quality reps of the right move, done consistently, until it holds up at game speed.
Is muscle memory real?
The habit is real, but it lives in the brain and nervous system, not the muscles. Research shows practicing a new motor skill drives changes in myelin, the insulation around nerve fibers that helps signals travel faster and more reliably.
How long does it take to change a swing?
Weeks to months, depending on the hitter and the change. At 50 quality swings a day, 10,000 reps takes about 200 days. Change one thing at a time, film it, and move from feel to repeat to speed to game reps.
Can bad practice build bad habits?
Yes. Your nervous system strengthens whatever you repeat, good or bad. That is why AHD checks every rep against video and ball flight. Feel isn’t real, so prove the rep before you repeat it thousands of times.
Why does my hitter learn swing changes slower than teammates?
Some hitters are 500s and some are 10,000s. It doesn’t mean he’s worse. He needs more quality reps, and slower learners often end up owning the move under pressure because they keep grinding.
Don’t collect drills. Build a complete hitter.
Want a coach to make sure your reps are the right reps? Contact Coach about online remote baseball and softball training, or private hitting lessons in Scottsdale.
Research: UCL, “Myelin vital for learning new practical skills” (2014); “Motor Skill Acquisition Promotes Human Brain Myelin Plasticity” (2016).
Complete Hitters Are Built… Not Given. Earned!
This article is part of the AHD guide Baseball Swing Mechanics. Start there for the full picture and every related article.
