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The odds ladder

SX Bet enforces an odds ladder to prevent diming (posting odds in tiny increments to gain an unfair edge). Your percentageOdds value must land exactly on one of the allowed steps, or your order will be rejected. The ladder works in intervals of the implied probability. The current step size is 0.125%, meaning valid implied odds are: 
50.000%, 50.125%, 50.250%, 50.375%, 50.500%, ...
An offer of 50.25% is valid. An offer of 50.20% is not.
Orders with odds not on the ladder will be rejected and will not be posted.

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Getting the current step size

The step size is available from GET /metadata. It returns a number from 0 to 1000:
Metadata valueStep size
100.010%
250.025%
1250.125%
The step size in raw percentageOdds units is: 
stepInRaw = metadataValue * 10^15
For the current default of 125: 125 * 10^15 = 1.25 * 10^17

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Checking if your odds are valid

To check if a percentageOdds value falls on the ladder, take the modulus with the step size and check if it equals 0: 
ODDS_PRECISION = 10 ** 20
ODDS_LADDER_STEP_SIZE = 125  # from GET /metadata

def is_odds_valid(percentage_odds: int) -> bool:
    step = ODDS_LADDER_STEP_SIZE * (10 ** 15)
    return percentage_odds % step == 0

# Valid: 50.250% implied = 50250000000000000000
print(is_odds_valid(50250000000000000000))  # True

# Invalid: 50.200% implied = 50200000000000000000
print(is_odds_valid(50200000000000000000))  # False

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Rounding to the nearest valid step

If your calculated odds don’t land on the ladder, round down to the nearest valid step before submitting: 
def round_odds_down(percentage_odds: int) -> int:
    """Round odds down to the nearest valid step on the ladder."""
    step = ODDS_LADDER_STEP_SIZE * (10 ** 15)
    return (percentage_odds // step) * step

# 50.200% → 50.125%
raw = 50200000000000000000
rounded = round_odds_down(raw)
print(f"{raw / ODDS_PRECISION:.3%} → {rounded / ODDS_PRECISION:.3%}")
# 50.200% → 50.125%

# 67.800% → 67.750%
raw = 67800000000000000000
rounded = round_odds_down(raw)
print(f"{raw / ODDS_PRECISION:.3%} → {rounded / ODDS_PRECISION:.3%}")
# 67.800% → 67.750%

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Full example: implied probability to valid percentageOdds

A common workflow: you have a fair probability (e.g., from your model), add margin, and need to convert it to a valid percentageOdds value. 
def implied_to_valid_odds(implied: float) -> int:
    """Convert an implied probability to the nearest valid percentageOdds (rounded down)."""
    raw = int(implied * ODDS_PRECISION)
    return round_odds_down(raw)

# Your model says 54.3% implied, you want to post at that price
odds = implied_to_valid_odds(0.543)
print(f"percentageOdds: {odds}")
# 54250000000000000000 (54.250%)

print(f"Implied: {odds / ODDS_PRECISION:.3%}")
# 54.250%

print(f"Valid: {is_odds_valid(odds)}")
# True
Always round down when posting maker orders. Rounding up would give worse odds for you. If you need to round to the nearest step in either direction, compare the distance to the step above and below.

Odds Formats →

Converting between implied, American, and decimal odds.

Unit Conversions →

Full reference for odds and token conversions.

Post New Order →

API reference for submitting orders.

GET /metadata →

Retrieve the current odds ladder step size.