How to keep a BJJ journal that actually improves your game

There are two ways to keep a BJJ journal. One is a diary: long entries, written when the motivation strikes, never re-read. The other is a book: structured, short, organized around the two things jiu-jitsu keeps handing you — the same positions and the same people — and built to be read again before you step on the mat.

This post is the system for the second kind. No app required (though we make one). Just a page per person, a page per problem, and about ninety seconds a session.

Why jiu-jitsu is built for a training journal

Two reasons. First, volume: live sparring is part of an ordinary class, so a normal training week produces more competitive rounds than many sports see in a month — and memory research is blunt about what happens to all that unwritten information. When researchers at the University of Amsterdam replicated Ebbinghaus’s classic forgetting-curve experiment under modern controls (PLOS ONE, 2015), the result confirmed the original: the steepest memory loss happens within the first day. The useful specifics of Tuesday’s rolls are measurably degraded by the weekend, replaced by a vague feeling of how the round went.

Second, structure: jiu-jitsu is position-driven. Things don’t just “happen” in a roll — they happen in chains, and chains repeat. Which means the failure that got you tapped on Tuesday is the same failure that will get you tapped in three weeks, unless it’s written somewhere you’ll re-read.

What to write in your BJJ journal after training

Skip the essay. You will not re-read essays. After class, three fragments:

What worked. Specific and situational, so it’s repeatable: “Knee cut finally landing when I get the cross-face first — worked on both bigger partners.”

What got me. Not the submission — the chain. The submission is the last link and usually the least fixable one: “Same loop twice: half guard, lost the underhook, flattened, back taken. The mistake is at the underhook, not the choke.”

One thing to try next time. A single sentence, imperative mood: “First roll tomorrow: enter half guard on purpose and fight only for the underhook.”

That last line quietly turns the journal into a training plan. You walk into every session with an assignment from yesterday’s self. This loop has evidence behind it: a study in the Journal of Sports Sciences compared 159 elite youth soccer players with 285 non-elite peers and found that reflection was among the traits most strongly associated with competing at the elite level — the elite athletes knew their own strengths and weaknesses better and trained accordingly. It’s also the mechanism behind Anders Ericsson’s theory of deliberate practice (Psychological Review, 1993): improvement comes from practice aimed at specific weaknesses, and you can only aim at a weakness you’ve identified. We’ve written a longer review of the reflection research if you want the full picture.

Keep a page per opponent — and per training partner

This is where a training journal becomes an opponent book — and in BJJ, “opponent” includes your training partners, because they’re the ones shaping your game five days a week.

For each regular partner, and every competitor you meet more than once, four short blocks:

The frame. Build, belt, gi or no-gi preference, and the shape of their game: “Pressure passer, heavy on the knee cut, almost never stands in your guard.”

What scores on them. “Doesn’t respect the collar grip until it’s too late — bow-and-arrow from the back landed both times.”

What scores on you. The uncomfortable column, and the valuable one: “Three taps to the same arm-in guillotine. Every one started with me shooting from too far out.”

Next time. Written for the version of you who has thirty seconds before the round: “Do not play open guard. Wrestle up early, before they settle their grips.”

Side and grip specificity earns its keep here. “Chokes from the right, sweeps to the left” is the kind of note that feels too small to write down and then wins you a round six months later.

Competition scouting works the same way, with better inputs: brackets in regional jiu-jitsu recycle the same names season after season, and competition footage is often a search away. The evening the bracket is published, pull your pages for every name you know and write frames for the ones you don’t.

When to write your training notes

The habit lives or dies on timing, not volume:

1. Within the hour after class. Changing room, bus home. Three fragments while the rolls are still distinct from each other — by tomorrow they’ve merged into one blurry session.
2. The night before competition, read — don’t write. Every page for every name you might meet. Ten minutes.
3. Note that you read. Over a season, compare how you perform walking in prepared versus cold. That number either justifies the habit or kills it; both answers are worth having. (OpponentBook tracks this correlation automatically; on paper, a checkmark in the margin does it.)

The self-scouting dividend: finding your leaks

After a couple of months, read only the “what got me” column, across every partner. The same sentence will appear in different rounds against different people — the lost underhook, the exposed neck in scrambles, the guard that gets flattened by anyone with pressure. That list is not their skill. It’s your leak, isolated better than any single frustrating night could show — and it’s the most useful thing you can hand your coach: not “I keep getting caught” but “here are the last five taps and four of them started at the same grip.”

One warning: this book is honest, so treat it like it’s private

A real BJJ journal contains your reads on the people you train with every week and a plain-language list of your own weaknesses. The jiu-jitsu world is small and gyms are smaller. Notes like that are tactical secrets, and where you keep them matters.

That’s the shape of OpponentBook: the structured debrief after every session, a page per partner and opponent, positional pins on a real mat diagram, your clips attached — synced across devices and stored on your own cloud storage, where we structurally cannot read a word of it. With optional end-to-end encryption, not even your storage provider can. The whole journal is free.

But the habit doesn’t need us. Tonight, after class: what worked, what got you, what you’ll try tomorrow. Three lines. The white belt who writes them down and the one who doesn’t are different grapplers by spring.