Class BettingOddsCalculator

java.lang.Object

org.episteme.social.sports.BettingOddsCalculator

public final class BettingOddsCalculator
extends Object

A utility for calculating betting odds, probabilities, and expected values for sports matches. Uses underlying rating systems (like Elo) and applies contextual factors.

Since:

1.0

Version:

1.1

Author:

Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	BettingOddsCalculator.MatchContext	Contextual factors that influence the outcome of a match.
static final record	BettingOddsCalculator.OddsResult	The result of an odds calculation, including probabilities and decimal odds.

Method Summary

Modifier and Type	Method	Description
static BettingOddsCalculator.OddsResult	calculateFromElo(Real ratingA, Real ratingB, BettingOddsCalculator.MatchContext context, double drawMargin)	Calculates match probabilities and odds based on Elo ratings and context.
static String	decimalToAmerican(double decimalOdds)	Converts Decimal odds to a formatted American format string.
static int	decimalToAmericanNegative(double decimalOdds)	Converts Decimal odds to US Moneyline (Negative).
static int	decimalToAmericanPositive(double decimalOdds)	Converts Decimal odds to US Moneyline (Positive).
static double	decimalToFractional(double decimalOdds)	Converts Decimal odds to Fractional odds. e.g., 2.50 -> 1.5/1 (returned as 1.5)
static Real	expectedValue(double stake, double decimalOdds, double trueProbability)	Calculates the Expected Value (EV) of a specific bet.
static Optional<Real>	findArbitrage(double oddsA_bookie1, double oddsB_bookie2)	Checks for an arbitrage opportunity between two bookmakers (Surebet).
static double	impliedProbability(double decimalOdds)	Calculates Implied Probability from Decimal odds.
static Real	kellyBetFraction(double trueProbability, double decimalOdds)	Calculates the Kelly Criterion fraction for optimal bet sizing. f* = (bp - q) / b where b = net odds (odds - 1), p = prob of winning, q = prob of losing.
static double	parlayOdds(List<Double> individualOdds)	Calculates combined odds for a Parlay (Accumulator) bet.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

calculateFromElo

public static BettingOddsCalculator.OddsResult calculateFromElo(Real ratingA,
 Real ratingB,
 BettingOddsCalculator.MatchContext context,
 double drawMargin)

Calculates match probabilities and odds based on Elo ratings and context.

Parameters:

ratingA - Elo rating of Team A

ratingB - Elo rating of Team B

context - Contextual factors

drawMargin - The "width" of the draw band in probability space (sport specific)

Returns:

OddsResult containing implied probabilities and bookmaker-style odds

decimalToFractional

public static double decimalToFractional(double decimalOdds)

Converts Decimal odds to Fractional odds. e.g., 2.50 -> 1.5/1 (returned as 1.5)

Parameters:

decimalOdds - Decimal odds

Returns:

Fractional numerator (denominator assumed 1)

decimalToAmericanPositive

public static int decimalToAmericanPositive(double decimalOdds)

Converts Decimal odds to US Moneyline (Positive). Used for underdogs (odds >= 2.00). Returns amount won on 100 stake.

Parameters:

decimalOdds - Decimal odds (> 2.0)

Returns:

Moneyline value

decimalToAmericanNegative

public static int decimalToAmericanNegative(double decimalOdds)

Converts Decimal odds to US Moneyline (Negative). Used for favorites (odds invalid input: '<' 2.00). Returns stake needed to win 100.

Parameters:

decimalOdds - Decimal odds (invalid input: '<' 2.0)

Returns:

Moneyline value (negative integer)

decimalToAmerican

public static String decimalToAmerican(double decimalOdds)

Converts Decimal odds to a formatted American format string.

Parameters:

decimalOdds - Decimal odds

Returns:

String like "+150" or "-200"

impliedProbability

public static double impliedProbability(double decimalOdds)

Calculates Implied Probability from Decimal odds. P = 1 / Odds

Parameters:

decimalOdds - Decimal odds

Returns:

Probability (0-1)

expectedValue

public static Real expectedValue(double stake,
 double decimalOdds,
 double trueProbability)

Calculates the Expected Value (EV) of a specific bet. EV = (Prob * Profit) - (LossProb * Stake)

Parameters:

stake - Amount wagered

decimalOdds - Odds offered

trueProbability - The 'actual' probability of winning

Returns:

Expected Value

kellyBetFraction

public static Real kellyBetFraction(double trueProbability,
 double decimalOdds)

Calculates the Kelly Criterion fraction for optimal bet sizing. f* = (bp - q) / b where b = net odds (odds - 1), p = prob of winning, q = prob of losing.

Parameters:

trueProbability - Estimated probability of winning

decimalOdds - Odds offered

Returns:

Fraction of bankroll to bet (0.0 if EV is negative)

findArbitrage

public static Optional<Real> findArbitrage(double oddsA_bookie1,
 double oddsB_bookie2)

Checks for an arbitrage opportunity between two bookmakers (Surebet). Occurs if the sum of implied probabilities is less than 1.

Parameters:

oddsA_bookie1 - Odds for Outcome A at Bookie 1

oddsB_bookie2 - Odds for Outcome B at Bookie 2

Returns:

Optional containing the percentage profit (ROI) if arbitrage exists

parlayOdds

public static double parlayOdds(List<Double> individualOdds)

Calculates combined odds for a Parlay (Accumulator) bet. Multiplies distinct event odds together.

Parameters:

individualOdds - List of decimal odds for each selection

Returns:

Combined decimal odds