# Best available price on each side, different books Book A: Team X +105 -> 48.8% Book B: Team Y +110 -> 47.6% implied sum = 48.8% + 47.6% = 96.4% # < 100% # Staking both sides in proportion locks ~3.6% regardless of result
On one book the implied sum measures how expensive the market is (see overround). Across books it measures how far the market disagrees with itself - the disagreement arbitrage and middling monetize.
The arb scanner continuously computes cross-book implied sums from the aggregated feed and surfaces markets where the sum drops below 1.0. You can reproduce it from the raw odds endpoints: take the best price per side across books, convert to implied probability, and sum.