Everything so far treated risk per trade as one number. The last layer — the one that separates professionals from disciplined amateurs — is that the number should flex with the quality of the opportunity. Small and constant for ordinary trades; decisively larger on the rare setups that carry your year. Done early, this destroys accounts. Done after Lessons 1–4 are habits, it's where the real money is made.
"For the best traders in the world, 80% of profits come from 5% of trades. That's because they know when to bet big. But most traders size up too early and blow up."
— Lance Breitstein, "The Trade Sizing Strategy that Made Me Millions" (0:00) — source videoThe prerequisites — hear them before the method
Breitstein prefaces the whole idea with two conditions, and they're load-bearing. One: you can genuinely tell an A+ trade from a B trade in real time — which requires a written, tested playbook and, in his words, "a close eye to nuance and a lot of experience." Two: you can carry bigger size without it corrupting your entries, exits, or judgment — size changes psychology, and if it changes yours, the bigger bet has lower expectancy, not higher. If either condition fails, the correct sizing system is the flat one from Lesson 3. There's no shame in that; there's just sequence.
The A/B/C/D grading system
His scale, from the same talk: an A trade appears once or twice a month — the standout opportunity you'll remember at year-end, and the one that justifies aggressive size. A B trade is one of the best trades of the day — good, common, worth full standard risk. A C trade is a small-edge everyday scalp — small size, no ego. A D trade is the bored, 50/50 impulse that loses money after costs — the grade exists so you can name it and skip it. His illustration of the range: standard risk on a B trade, and — when conviction and liquidity allow — up to ten times that on a true A+. The exact multiples are his; the structure is the lesson. This is the same discipline as the trade grading & sizing framework and SMB's A+/B/C system in Build Your Playbook.
Notice this is fractional-Kelly thinking in working clothes: edge up → size up, uncertainty up → size down (Lesson 4) — implemented through pattern recognition and a grading vocabulary instead of a formula. The old-school version is Bruce Kovner's advice in Market Wizards — undertrade as a rule, know your exit before you enter — the floor under everything this lesson adds.
The honest failure mode
The catastrophic version of this lesson is running it backwards: sizing up out of frustration (revenge), out of recency (three wins in a row), or out of boredom — grading the trader's mood instead of the trade. The defense is mechanical: the grade must be assigned from written playbook criteria before entry, and your journal (Lesson 2) must track expectancy by grade. If your "A" trades don't measurably outperform your "B" trades over a real sample, your grading isn't ready to size on — and now you know, which is the point of measuring.
Capstone assignment
Add a grade column to your journal. For one month, grade every trade before entry against written criteria — but don't change your sizing yet. At month's end, compute expectancy per grade. That report is your license: if the grades separate, you've earned the right to let size follow quality, gradually. If they don't, you've saved yourself the blowup Breitstein warns about — and you know exactly what to refine in your playbook.