Rob Griffiths.

Insurance is a negative-EV bet - for you. Here's how actuarial science, risk pooling, and the law of large numbers turn that into reliable profit.

Travel insurance is usually negative-EV, yet often the right call. The expected-value rule for when a risk is worth insuring - and when to self-insure.

Same average return, wildly different outcomes: why the ORDER of your returns decides how long a pension pot lasts. Sequence-of-returns risk explained.

Expected value thinking: the most important concept in decision-making under uncertainty. What it is, how to calculate it, when to apply it.

15 best decision-making books - choice architecture, behavioural economics, frameworks, and habits. Mini-reviews, who each is for, and reading order.

A guide to Nassim Taleb's key ideas - Black Swans, Antifragile, Skin in the Game, fat tails, barbell strategy and the Lindy effect - and where to start.

Kahneman's Thinking, Fast and Slow is the canonical text on cognitive bias. What it gets right, what hasn't aged well, and whether to buy it.

Annie Duke's Thinking in Bets reframes every decision as a bet under uncertainty. The ideas of resulting, calibration, and decision groups.

A curated reading list on probability, decision-making under uncertainty, and rational thinking - from Kahneman to practical guides for forecasters.

Prediction markets turn questions about the future into tradeable contracts whose prices behave like probabilities. How they work, and how to use them.

How to apply probabilistic thinking to medical decisions, career bets, insurance, investing, dating, sports betting and travel. 7 worked examples.

Status quo bias explained: the cognitive tendency to stick with defaults. UK financial impact: pension funds, insurance renewals, current accounts.

Knowing you have an edge is half the battle - sizing positions correctly is the other half. How to size bets so you don't blow up or waste your advantage.

Expected value in poker - pot odds, implied odds, EV of bluffs and folds. Worked hand examples showing how the maths translates into better decisions.

Learn how to calculate expected value with a clear formula, four worked examples (betting, investing, insurance, career) and the common mistakes to avoid.

Monte Carlo simulation lets you stress-test decisions across thousands of scenarios. A practical guide to using it for retirement, projects and investing.

The expected value formula is E[X] = Σ(p × x). Full derivation and five worked examples - coin flip, lottery, insurance, poker, and stock investment.

Full Kelly is mathematically optimal but emotionally brutal. Why half Kelly is the practical default, when to scale up or down, and how the pros use it.

The Gambler's Fallacy: why we wrongly believe random outcomes are 'due'. The cognitive trap, where it costs you, and how to think clearly under randomness.

Pure expected value can lead to ruinous decisions. Here's why expected utility, risk aversion, and the St Petersburg paradox matter for real-life choices.

The 12 cognitive biases that most consistently distort probability judgements - what each one does and how to defend against it.

Decision trees turn tangled choices into a diagram you can actually solve. Build one in five steps, work through three examples, and avoid common traps.

Hindsight bias makes the past feel inevitable. Here's why it distorts post-mortems, juries and investing - and how to fight it.

Ergodicity separates sensible bets from catastrophic ones. The difference between ensemble averages and time averages - and why ignoring it can ruin you.

Conditional probability is the chance one event happens given another already has. Worked examples in medical testing, weather, and the Monty Hall problem.

Loss aversion: why losses hurt twice as much as equivalent gains feel good. The Kahneman/Tversky research, where it warps decisions, and how to counter it.

Confusing P(evidence | innocent) with P(innocent | evidence) sends innocent people to prison. The Sally Clark case and how to spot the trap.

The Dunning-Kruger effect: the gap between how good people think they are and how good they actually are. The real research is more useful than the chart.

Bayesian thinking - the art of changing your mind rationally. How to update beliefs with evidence, with examples from interviews, medicine, and investing.

Risk is measurable; uncertainty is not. Confusing the two produces overconfident forecasts and brittle portfolios. Here's how to tell them apart.

The Law of Large Numbers explains why a single bet is wildly volatile but casinos profit reliably - the maths behind insurance and long-run averages.

Anchoring bias: why the first number you hear silently warps every estimate that follows - with research, examples, and debiasing strategies that work.

Base rate neglect is one of the most costly cognitive biases. Why most positive medical tests are wrong, and how to train yourself to think in base rates.

Decision making under uncertainty frameworks: minimax regret, expected utility, satisficing, maximax compared. When each applies.

Mental accounting fallacy: separating money into psychological 'buckets' distorts financial decisions; budgeting + investment implications.

Why we judge risk by what comes to mind first - fear of flying, market news, terrorism - and the practical techniques to debias your thinking.

Why every lottery ticket, roulette spin and slot pull is mathematically a loss in expectation. The maths behind why the house always wins.

Use expected value, scenario planning and Kelly-style sizing to evaluate job offers, career pivots and salary negotiations honestly.

Probability and odds describe the same uncertainty differently - and confusing them costs people money. How each works, conversions, and bookmaker tricks.

Step-by-step Kelly Criterion calculator with worked examples for sports betting, investing and poker. Convert odds to stake percentages instantly.

When a test for a rare condition comes back positive, it's often more likely wrong than right. The false positive paradox, explained with real numbers.

A 0.35% platform fee sounds tiny. Compounded over 25 years it can cost £30,000+. The maths of fee drag, and where flat fees beat percentages.

Probability weighted utility for high-stakes decisions: combining probabilities and personal values for better choices.

Bayesian updating UK 2026: practical examples of updating beliefs with new evidence in investment, health, and career decisions.

Conjunction fallacy in business: how compound probability errors distort startup planning, investment scenarios, project timelines.

The sunk cost fallacy: why we keep investing in losing decisions. The bias, the psychology, and a clear test for when to quit and when to persist.

Risk aversion vs loss aversion: the behavioural distinction; investment + portfolio implications; how each affects decisions.

Most decisions are made on first-order effects, but second-order consequences are where the surprises live. A framework for seeing past the obvious.

EV in poker tournaments: ICM considerations, bubble dynamics, when raw chip-EV diverges from actual tournament-EV.

Black swan events explained: Taleb's definition, examples (2008, COVID, AI surge), and the barbell strategy + antifragility approach.

Your brain systematically misjudges probability. Learn the cognitive biases that distort risk perception and how to calibrate better.

Correlation is not causation - the most-quoted line in statistics, and the most misunderstood. What it really means, and how to think clearly about cause.

Learn probability calibration like a superforecaster - Brier scores, drills, and free tools to sharpen your forecasts. Based on Philip Tetlock's research.

A UK FIRE roadmap for 2026: the 4% rule, your real number, the tax-wrapper order, and the ISA bridge to pension access age. Honest maths, no hype.

Warranty maths retailers hope you never do: premium vs failure odds x repair cost. Why most UK cover is -EV, and the one case where it isn't.

Raising your voluntary excess cuts your premium but raises claim costs. Use expected value to find the excess level that actually pays off.

The Kelly Criterion tells you exactly how much to stake when you have an edge. Formula derivation, fractional Kelly, history, and worked examples for 2026.

Premium Bonds advertise 3.8%, but that average hides a skewed reality. Here's the real expected (and typical) return for £1k, £10k and £50k holdings.

Almost every bet is negative-EV by design. Here are the few places an ordinary person can genuinely find positive expected value.

The 2026/27 stocks and shares ISA limit is £20,000. Here's how the allowance works, what the April 2027 cash ISA cut means, and how to use it.

Bayes theorem explained from the formula up: derivation, intuitive examples (medical tests, spam filters), and the base-rate trap that fools experts.

The framing effect: identical numbers presented differently produce opposite decisions. Asian Disease Problem, gain vs loss framing, defences.

Availability cascade in markets: how compounding information cascades amplify trends, create bubbles, and drive systematic mispricing.

The Monty Hall problem looks 50/50 and isn't - switching doors wins two-thirds of the time. Here's why, with five proofs and the famous controversy.

Bayesian vs frequentist statistics - the philosophical split that decides whether you get p-values or posteriors, and when each one actually wins.

Recency bias: why investors chase last quarter's winners and bettors back the form team. The mechanics, the cost, and the four tools that defuse it.

Survivorship bias hides the failures behind every success story - from WWII bombers to mutual funds. How to spot the missing data and decide better.

Overconfidence bias is investing's most expensive cognitive error. How overestimation, the planning fallacy and overprecision hide it, and what fixes it.

Confirmation bias quietly destroys investment returns. Here's how it works in markets - and the three techniques that actually neutralise it.

Why extreme performance - sporting peaks, market gains, viral hits - almost always reverts to average. Galton's discovery, examples, and how to spot it.

The pre-mortem flips the post-mortem on its head: imagine the decision has already failed, then work backwards to find what optimism hides.

The endowment effect makes you value the things you own more highly than identical things you do not. Here is why it happens, with worked examples.

A decision journal is the only honest record of how well you actually think. What to record, when to review, and the mistakes that ruin the practice.