# Deciding Under Uncertainty > Hardens a recommendation on a consequential, hard-to-reverse call into a calibrated bet with a pre-agreed exit, instead of a single confident verdict. Use when advising or deciding: build vs buy, adopt or swap a dependency or platform, migrate now or wait, rewrite vs refactor, quit or double down, ship or delay - any "should we / should I" where being wrong is expensive to undo. Also for judging a past decision fairly. Not for generating design alternatives - the design-forking skill owns widening the option set; this skill disciplines the commitment once a leading option exists. - Skill: `connorads/deciding-under-uncertainty` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add connorads/deciding-under-uncertainty` - Raw SKILL.md: https://api.skillmd.com/api/skills/connorads/deciding-under-uncertainty/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: connorads (https://skillmd.com/u/connorads) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/connorads/deciding-under-uncertainty --- # Deciding Under Uncertainty The failure this fixes: asked a consequential "should we?", an agent researches well, then lands the answer as a verdict - "My call: X. That's a weekend." Confident, plausible, and missing everything that makes a decision defensible or cheap to exit: no odds, no reference class, no failure rehearsal, no pre-agreed way out. Advice on a hard-to-reverse call is a **bet**; deliver it with a bet's machinery. The classic checks (sunk cost, pros/cons, the successor test) need no help - don't pad the answer with them. The five moves below are the ones consistently skipped. ## 0 - Gate Same doors as design-forking. Cheap to reverse: answer plainly, note the reversal path in one line, stop - odds and tripwires on a two-way door are ceremony. Hard to reverse with only one option on the table: widen the set first (design-forking owns that), then return here to commit to the winner. ## The five moves **1 - Reference class before inside view.** Name the class this decision belongs to and how it usually goes - "solo-dev auth hand-rolls", "big-bang rewrites of untested code", "CI speed migrations" - before reasoning about this instance's specifics. The inside view is where motivated reasoning lives; the base rate anchors it. One or two sentences; a named class with a typical outcome beats a statistic you would have to invent. **2 - Odds, not a verdict.** State the recommendation with a calibrated probability - "roughly 75% this still looks right in six months" - plus the one observation that would most move the number. A percentage without a mover is decoration; the mover is what makes the number falsifiable. **3 - Premortem, not a risk list.** Assume the recommendation was taken and failed: write the single most likely post-mortem sentence. "We took the library route and ripped it out six months later because ..." A list of generic risks is inside-view hedging; the premortem forces one concrete causal story - and that story usually names the assumption to probe (move 5) and the tripwire to set (move 4). **4 - Tripwires that outlive the conversation.** Pre-agree the exit: an observable predicate + a checkpoint + the action. "If the pilot hasn't cut CI install below 2 minutes by end of sprint, stay put" - not "revisit later" or "reconsider if problems arise". Then write the tripwires where the project keeps decisions (ADR, tracking issue, an AGENTS.md note): a tripwire that exists only in the chat dies with the session, and without the record the decision will later be judged by its outcome alone. **5 - Ooch before the bet.** Propose the smallest reversible probe that tests the premortem's assumption - a timeboxed spike, one route migrated, one package piloted - and say what result would flip the call. Skip it, and say so, when the probe costs more than being wrong or when delay itself is the biggest cost. ## Deliver as advice, not a filled-in template The moves are scaffolding; the reader gets their fruits woven into normal advice, never a five-heading ceremony. Lead with the recommendation and its odds; the reference class is a clause; the premortem is "the way this goes wrong is ..."; the tripwires are a short "revisit if" block at the end. No skill vocabulary (ooch, premortem, reference class) in the answer. Proportion the machinery to the stakes: a platform migration earns the full set; a mid-sized call may earn odds and one tripwire. ## Judging past decisions Grade the decision, not the outcome: what was known at the time, and was the process sound - real alternatives, stated odds, an exit? A good bet can lose; a bad bet can win. "Bad outcome, right call given what was known" is a legitimate verdict, and recorded tripwires (move 4) are what make it reachable later. ## Worked example (compressed) "Monorepo pnpm installs feel slow in CI - migrate to bun?" - Gate: whole-repo package-manager swap - expensive to undo. Full set. - Reference class: CI install complaints are usually cache misses, not resolver speed; most such migrations buy less than warming the cache. - Odds: ~80% that store caching makes the migration moot; drops sharply if a warm-store install is still the bottleneck. - Premortem: "we migrated, then hit workspace and lifecycle semantics that differ at monorepo scale, and lost install-gating we relied on". - Tripwire (recorded on the tracking issue): warm-store CI install still over 2 minutes after caching lands this sprint -> run the bun pilot; otherwise close. - Ooch: cache the store keyed on the lockfile hash this week - cheapest probe, tests the reference-class hunch directly. Delivered: "Wait - fix caching first. Slow CI installs are nearly always cache misses rather than the package manager, so I'd put ~80% on caching making this moot. Revisit if a warm install still tops 2 minutes after this sprint - I've noted that on the issue - and if it does, pilot bun in one package before touching the monorepo." ## Anti-patterns - A percentage as decoration - "80% confident" with nothing named that would move it. - A risk list wearing a premortem's clothes - five hedges instead of one causal failure story. - "Revisit later" - a tripwire missing its predicate, checkpoint, action, or a home outside the chat. - Hedging both ways to dodge the odds - the deliverable is still a recommendation; the machinery makes it defensible, not optional. - Running the full set on a two-way door - ceremony that teaches the user to stop asking. - Narrating the moves in the answer.