A library for thinking under uncertainty.
Cognitive biases, tail risks, antifragility, decision protocols. Vladyslav's practical notes on Kahneman and Taleb - turned into a searchable system for better decisions.
Concepts and mental models
Base rate (and base-rate neglect)
The background frequency of something across the relevant population - and the chronic mistake of ignoring it in favour of vivid specifics.
Open conceptOverconfidence
We are systematically more certain than we should be, especially about predictions and our own judgment.
Open conceptNarrative fallacy
We turn messy reality into clean stories. Stories explain in hindsight but predict almost nothing.
Open conceptBlack Swan
A rare, high-impact event that is unpredictable beforehand and feels obvious afterwards.
Open conceptMediocristan
Domains where no single observation dramatically changes the total - physical attributes, repeating natural processes, well-bounded quantities.
Open conceptExtremistan
Domains where a single observation can dominate the total - wealth, book sales, pandemic spread, social-media reach, war casualties.
Open conceptThick tail (and thin tail)
In thick-tailed distributions, extreme events are more frequent and more extreme than the bell curve predicts. The tail does most of the work.
Open conceptSilent evidence
The data you don't see - failures, drop-outs, missing cases - usually changes the conclusion. The story you can hear is biased by survivorship.
Open conceptSurvivorship bias
Drawing conclusions only from the survivors of a selection process, ignoring everyone the process eliminated.
Open conceptRuin
The class of outcomes from which you cannot recover. Ruin doesn't average out, doesn't get reversed by a winning streak, and ends the game.
Open conceptExposure
The shape of what happens to you under different outcomes - not the probability of those outcomes. Manage exposure, not forecast.
Open conceptOptionality
The asymmetric right (not obligation) to take advantage of good outcomes without being trapped by bad ones.
Open conceptBarbell strategy
Combine extremely safe positions with extremely risky ones. Avoid the «moderate» middle, which has thin-tail-thinking risk you can't see.
Open conceptPositive asymmetry (convexity)
Shape your bets so the downside is small and the upside is large. The asymmetry - not the probability - is what generates positive long-run results.
Open conceptSkin in the game
Trust advice and decisions from people who pay the cost of being wrong. Distrust those who don't.
Open conceptDoxastic rules
Belief-handling rules: track confidence as a number, update it on evidence, and gate big actions behind high p.
Open conceptEpistemic arrogance
Confidence that vastly exceeds the quality of evidence - usually because the speaker can't see what they don't know.
Open conceptIatrogenics
Harm caused by the intervention itself. Treatment that's worse than the disease.
Open conceptEpilogism
Reasoning by pattern from concrete observable cases, refusing to extrapolate beyond what's directly seen.
Open conceptPractical templates
Tail Risk Scan
Map where you're exposed to outcomes you can't recover from.
Barbell Strategy Planner
Restructure a position (career, portfolio, project) into an extreme-safe + extreme-upside combo.
Doxastic Confidence Update
Track and update p - your belief level in a hypothesis - as evidence arrives.
Concept comparisons
Fragile vs Robust vs Antifragile
Any system you can't easily rebuild. Career, relationships, supply chain, codebase.
Open comparisonMediocristan vs Extremistan
Whenever you plan to «average» something. First classify the domain.
Open comparisonInside View vs Outside View
Every project estimate, every revenue forecast, every commitment.
Open comparisonAvailability vs Base Rate
Risk estimation, hiring, forecasting, anything where vivid recent memories influence judgment.
Open comparisonWYSIATI vs Silent Evidence
Any decision based on success stories, expert testimony, or curated examples.
Open comparisonOptionality vs Forecasting
Any high-uncertainty bet: career, product, market timing. Default to optionality.
Open comparisonThis part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.