Reinhardt Grobler spent the first half of his career putting prices on uncertainty. He trained as an actuary in Cape Town and worked for over a decade in life insurance, building mortality and annuity models — the unglamorous discipline of turning probability into a number somebody has to pay. He then moved to the trading floor of a licensed sports betting operator, compiling fixed odds and managing the book's exposure, where he learned the difference between a probability that is correct and a price that survives the weekend.
Poker arrived through a Tuesday home game with colleagues from the trading room. He noticed that the game's arithmetic — outs, pot odds, implied prices — was the same craft he had practised all along, done faster and with worse information, and he has been unable to leave it alone since. He plays modest online cash stakes and the same home game, and is direct that his edge, such as it is, comes from never miscounting rather than from any talent for reading people.
On this site Grobler writes the mathematics: odds and outs, equity, pot odds and expected value, and the conversions between the formats players actually meet at the table. He also builds and maintains the site's calculators, and audits every one against the combinatorics by hand before it ships — his standing rule is that a tool nobody can check is a rumour with a user interface.
He is precise about his limits. He does not write strategy, does not tell readers when to bluff, and treats his own results as too small a sample to mention. Where a number is exact he shows why, and where it is an estimate he says so and shows how wide. Twenty years of pricing risk taught him that the confident number is usually the wrong one.
