Mistake-pair co-occurrence counts how often two mistake-tags appear together on the same trade and reports the conditional probabilities P(B|A) and P(A|B). The asymmetry between the two conditionals is itself a signal — a rare tag that always co-occurs with a common one points to the common one as the upstream trigger.
A trade with three mistake tags contributes to all three pairs (combinations(3,2)=3). Within-trade duplicates are dropped (a 'fomo' tag applied twice doesn't pair with itself).
Across the analysis window: 'fomo' on 8 trades, 'no stop' on 7 trades. Co-occurrence on 6 trades. P(no stop | fomo) = 6/8 = 75%. P(fomo | no stop) = 6/7 ≈ 86%.
Why pairs not single tags. A trader who treats FOMO and no-stop as separate problems writes two journal rules and polices both — twice the cognitive load with half the leverage. The pair tells you ONE state is producing both symptoms. Write a single rule against the upstream state and both downstream behaviours drop simultaneously.
Reading the asymmetry. If P(B|A) >> P(A|B), then A is the upstream trigger (every time A happens, B is overwhelmingly likely; B is more independent). If P(B|A) ≈ P(A|B), the two are deeply entangled — neither is independent. If both are high, you've got a tilt fingerprint; if both are low but co-occurrence count is high, you've got a coincidence (filter says no emission).
Tier: Pro. Wave 6 (Mistake Analysis).
How to read the card: Hero shows the strongest pair's max conditional. Table lists each pair with both conditionals (P(A|B) / P(B|A)) so you can read the asymmetry directly. Re-look monthly.
Tier: Pro.