Kelly criterion calculator: optimal ποντάρισμα sizing

How this calculator works

The Kelly criterion is a mathematical formula developed by John L. Kelly Jr. in 1956 to determine the fraction of a bankroll that maximises the long-run logarithmic growth rate of wealth. It is the most rigorously derived bankroll management rule in existence.

The full Kelly formula is: f* = (bp - q) / b, where b is the net decimal αποδόσεις (decimal - 1), p is your estimated πιθανότητα of winning, and q = 1 - p. For example, if the αποδόσεις are 2.00 (b = 1.00) and you estimate a 55% win πιθανότητα, f* = (1.00 x 0.55 - 0.45) / 1.00 = 0.10, meaning 10% of your bankroll.

A negative Kelly result means the bet has no edge: the implied πιθανότητα of the αποδόσεις exceeds your estimated win πιθανότητα. The calculator displays this as 0% and flags the negative edge.

Many professional bettors use Half Kelly (0.5x) or Quarter Kelly (0.25x). These fractions reduce variance significantly at a modest cost to long-run growth rate. Full Kelly is mathematically optimal but carries substantial short-term drawdown risk. With Half Kelly, the standard deviation of outcomes roughly halves.

The edge figure shown is (p x decimal) - 1, representing your expected return per unit ποντάρισμαd. A 5% edge on a 10-unit bet generates 0.50 units of expected value per wager on average.

Accurately estimating win πιθανότητα is the hardest part of applying Kelly. If your πιθανότητα estimate is wrong by even a few percentage points, Kelly can recommend ποντάρισμαs that are too large. Many practitioners apply a further 50% haircut to their estimates as a safety margin, effectively running at Quarter Kelly even when they επίλεξε Half Kelly mode.

Why use it at 1win

1win covers 30+ αθλήματα with competitive αποδόσεις across 40,000+ καθημερινά αγορές. If you have identified an edge, Kelly tells you exactly how much to ποντάρισμα. Εγγραφή with XLBONUS to open an λογαριασμό and start applying systematic bankroll management from your first bet.

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