Of all the rules in Model 1, this is the one that's hardest to keep and earns the most: at most one trade per strategy per day. Not "one winning trade", not "one, unless the first doesn't work out". One. Then the shop closes.
What the rule actually restricts
On the surface it limits the number of trades. In reality it limits something else: the number of decisions I make under emotion.
The most dangerous trade of the day isn't the first one. It's the second — taken after a loss, because "the setup was valid and the market owes me". Or after a win, because "I'm on today". Both come from the same source: a feeling, not a plan. The one-trade limit cuts that source off mechanically, with no debate.
Frequency is a property of the data, not of performance
Model 1 on GBPUSD produces on average one to two mechanical trades per month. That's few — and that's correct. The setup requires several conditions to line up at once: liquidity in the right place, a sweep, confirmation, a retest within the session. Days without a trade aren't wasted days; they're days when the conditions didn't occur.
This, incidentally, is why you'll find empty days in my journal and why I don't skip them. An empty day is a data point too — it says I didn't trade when the model was silent. For evaluating discipline it matters as much as a target hit.
"Followed the plan" measures behaviour, not outcome
Every entry in my journal has a followed the plan field. Deliberately, it doesn't measure whether the trade made money — it measures whether I did exactly what the rules say: entry at the retest, stop beyond the extreme, 3R target, no moving, no early exit.
A losing trade with the plan followed is a cost of running the strategy. A winning trade with the plan broken is the worse outcome long-term — it reinforces behaviour that will eventually expose the account. That's why the journal measures the two axes separately.
Discipline is designed, not forced
I don't believe in willpower as a permanent solution. I believe in an environment that doesn't even offer the bad decision. The one-trade limit, fixed 0.5% risk, set & forget after entry, the record written on the day of the trade — these are all design elements that reduce the number of places where cheating is possible.
If you take one thing from this article: don't try to be more disciplined. Build a system in which being undisciplined takes more effort than being disciplined.