Kelly criterion calculator: optimal tét sizing
1win is engedélyezett under Curaçao 8048/JAZ and offers 400,000+ regisztrált játékosok a sportkönyv with 40,000+ piacok. This free Kelly criterion calculator shows you the optimal tét size for any edge you hold over the bookmaker. Alkalmazásly code XLBONUS at regisztráció and put your bankroll to work immediately.
Kelly criterion calculator
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 szorzók (decimal - 1), p is your estimated valószínűség of winning, and q = 1 - p. For example, if the szorzók are 2.00 (b = 1.00) and you estimate a 55% win valószínűség, 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 valószínűség of the szorzók exceeds your estimated win valószínűség. 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 tétd. A 5% edge on a 10-unit bet generates 0.50 units of expected value per wager on average.
Accurately estimating win valószínűség is the hardest part of applying Kelly. If your valószínűség estimate is wrong by even a few percentage points, Kelly can recommend téts 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 válaszd ki Half Kelly mode.
Why use it at 1win
1win covers 30+ sportok with competitive szorzók across 40,000+ napi piacok. If you have identified an edge, Kelly tells you exactly how much to tét. Regisztráció with XLBONUS to open an fiókot and start applying systematic bankroll management from your first bet.
Gyakori Kérdések
What is Full Kelly vs Half Kelly?
Full Kelly bets the theoretically optimal fraction but has high short-term variance. Half Kelly bets half that fraction, which roughly halves variance while retaining about 75% of the optimal growth rate. Quarter Kelly is even more conservative.
What does a negative Kelly result mean?
A negative result means the bet has no edge: the bookmaker's price implies a higher valószínűség of winning than your own estimate. You should not place this bet according to Kelly theory.
How accurate must my probability estimate be?
Even a 2-3 percentage point error in valószínűség can materially change the recommended tét. Always apply a margin of safety, and many professionals use Half or Quarter Kelly to fiókot for estimation error.
Can Kelly be used for casino games?
Kelly applies to any bet with kmostn szorzók and positive expected value. Most kaszinójátékok have negative expected value, making Kelly recommend zero tét. It is most useful for sportfogadás and trading.
What is the "edge" in the Kelly formula?
Edge = (valószínűség x decimal szorzók) - 1. It represents expected return per unit tétd. A 5% edge means you gain 0.05 units on average per unit bet over many repetitions.