RookieNo. 3
Ready
3
Live
Season 1 · Week 1 of 6 · Science & History · Grades 3 & 4
Diamond Academy
Every lesson is a game. Every card is earned.
We homeschool our two boys, and they live for baseball. So instead of fighting it, I built their science and history curriculum into a baseball season. Each week is a unit. Each lesson is a game played around the bases. Mistakes cost nothing, cards are earned, and XP clears the fence toward real rewards like picking the movie or a late bedtime.
It runs at home on an iPad. There is no public sign-up and no link here on purpose. This page is a working replica of what the boys see, built so you can walk the same path they do: pick a player, check the dashboard, play a lesson, pull a card.
Player select
VeteranNo. 4
Ready
4
Step 2 · The pregame show
Night: your stats.
The dashboard reads like a broadcast. GP is lessons completed. AVG is first-try accuracy. HR is a nailed mastery question. Every number is derived from an append-only log, so nothing can be double-counted.
Player profile · #3
Beau
- GP
- 0
- AVG
- .000
- HR
- 0
- RBI
- 0
- SB
- 0
- XP
- 0
Live Continue season
Science · Week 1 — Thinking Like a Scientist
Lesson 1: Welcome to the Baseball Science Lab
123M
Inning 1 · Pregame · 95 XP on the line · about 25 minutes
Continue☾ Night: your stats.☀ Day: your lessons.
Lessons play in daylight
Next reward
Ice cream run
0 / 1,000 XP
02505007501,000
388 XP to go. About four lessons. Clear the fence to cash in.
250 · Pick the movie
500 · Late bedtime
1,000 · Ice cream run
1,500 · Ballpark day
Season 1 line score
Runs = XP earned each week
| Wk | 1 | 2 | 3 | 4 | 5 | 6 | XP |
|---|---|---|---|---|---|---|---|
| Science | 0 | ||||||
| History | 128 | 132 | 260 |
FinalLiveLocked
Step 3 · Play ball
Day: your lessons.
This is a real lesson from the curriculum, Grade 3 Science, Week 1, Lesson 1, playable right here. Go around the bases: answer the pregame question, read the scouting report, take your at bat, and close it out in the bottom of the ninth.
BeauScienceWeek 1 — Thinking Like a ScientistLesson 1
Grade 3 Science · Week 1 · Lesson 1
Welcome to the Baseball Science Lab
Linescore · XP by inningInn 1
| PG | SR | AB | 9th | GB | XP |
|---|---|---|---|---|---|
| – | – | – | – | 0 |
Now battingOn deck circle · Recall
Pregame
The team wants to know why some ground balls sneak through the infield. What should its science department do first?
Your call
A prediction is never wrong. It just gets tested.
On deck1st base · Learn
Scouting Report
Opens after Pregame.
Welcome to the lab, Beau. Every big-league club has a science and analytics department. Its job is to study the game carefully so the team can make better choices.
Scientists work the same way whether they study baseballs, bugs, or stars:
- They ask a question, like "Do ground balls roll farther on dirt or on grass?"
- They observe. That means they use their senses and tools such as a tape measure or a stopwatch.
- They collect evidence. Evidence is what they observed and measured, written down so anyone can check it later.
- They look for a pattern in the evidence and share what they found.
- Observe
To notice something carefully with your senses or with a tool.
- Observation
Something you noticed. "The ball rolled 12 feet" is an observation.
- Measure
To use a tool to find out how long, how heavy, how hot, or how fast something is.
- Evidence
Observations and measurements that are written down so they can be checked.
Scout the play
ThrowCatchHit
The pitcher throws.
Observation checkCould someone standing next to you see, hear, or measure the same thing? If yes, it is an observation.
Finish the report: +15 XP
Up next2nd base · Practice
At Bat
Opens after Scouting Report.
Question 2 of 3 · the real lesson also has a pick-every-one and a put-in-order question
A scout at a different game writes four notes. Which note is an observation?
Attempt 1
HintWhich note could another scout check with the same tool?
Not yet. Swing again.Mistakes cost nothing here. Every attempt is logged, none are penalized.
Base hit!A stopwatch reading can be checked, so it is an observation. "Best player" is an opinion, the breakfast is a guess about why, and stealing second is a prediction about later.
Final inningHome plate · Mastery
Bottom of the 9th
Opens after At Bat.
The team wants to know if a new glove helps the shortstop catch more ground balls. Which plan collects real evidence?
Attempt 1 · first-try correct = a home run
HintEvidence comes from observing and counting, and one try is not much to go on.
Foul ball.Still your at bat. Think about which plan someone else could repeat and check.
Walk-off!Counting catches with both gloves gives measurements anyone can check. One ground ball is too few to show a pattern, and looks or price are not evidence about catching.
BonusThe mound · Reflect
Game Ball
Bonus round. Opens after Bottom of the 9th.
What does a scientist do that a fan in the stands might not do? Use the words observe and evidence.
A little more.Three words minimum. Your text is still here.
Game ball awarded.Reflections are never graded. Writing it down is the point, and the parent guide for this lesson shows Mom and Dad what to ask about at dinner.
Hand it in: +10 XP
Step 4 · Postgame
Earn the card. Clear the fence.
Finish a lesson and a collectible card drops, one of 24 per season with four rarities. XP stacks toward a reward track the boys negotiated themselves. Pennants hang for streaks and perfect innings.
Cards earned
3 of 24 collected · tap a cardCommon#001
1
Rookie ScientistScience · Week 1
Rare#007
7
Matter ScoutScience · Week 2
Rare#012
12
Road WarriorHistory · Week 2
All-Star#018
18
State ChangerScience · Week 3
Finish the lesson above and the Rookie Scientist card flips face up.
Perfect 9th
3-lesson streak
Week 1 champ
No-hitter week
Season sweep
Game log
Recent- HRPerfect Bottom of the 9thScience · Wk 3 — States of Matter · +30 XP
- ALLPulled an All-Star: State ChangerScience · Wk 3 · Card #018
- SBEnrichment lesson done a day earlyHistory · Wk 2 · +10 XP
- RBIThree-lesson hit streakSeason · +15 XP
Step 5 · The front office
Under the hood.
Boring technology on purpose. Two students, one household, no multi-tenancy, no OAuth, no background jobs, no runtime AI. The whole thing is a single SQLite file and a folder of YAML.
72Lessons in Season 1
24 weekly units across Grade 3 and Grade 4, Science and History. Six weeks each, three lessons plus a hands-on Family Mission the boys do together.
YAMLCurriculum is data
Every lesson is a sequence of typed blocks in a YAML file. One rendering engine, one importer, zero lesson content in templates. Re-import is idempotent.
15Reusable animations
Pitch-catch-hit, fly ball, baserunner motion, energy chain, map regions, timelines. Stimulus modules driven by config, never per-lesson JavaScript.
0Penalty for mistakes
Attempts are recorded, never punished. AVG is first-try accuracy, mastery is eventual. XP is an append-only ledger with a unique key per award, so refreshes can't double-pay.
72Parent guides
Every lesson carries a concept, a goal, and a dinner-table check question for Mom and Dad. The admin side shows exactly what each boy was taught and where he got stuck.
2Days from concept to live
Six design concepts on a Sunday, architecture and contracts approved, then Claude Code agents built the engine, seeded the season, and wrote the specs. The boys played their first lesson Monday.
Rails 8.1SQLiteHotwire · Turbo + StimulusPropshaft + ImportmapTailwindRSpec · 500 specsDocker · GHCRHome server · CI auto-deployiPad firstBuilt with Claude Code
Why not just buy a curriculum? We tried. The good ones are dry, the fun ones are shallow, and none of them know that my 8-year-old will read three paragraphs about friction if the example is a slide into second base. Owning the whole stack means a lesson that doesn't land on Monday gets rewritten by Tuesday.
It is not for sale and it is not open to the public. It is one family's school year, built the way I build everything else.