Definition
Juice is slang for vig — the cost embedded in betting prices. Paying juice means accepting odds worse than true probability. On a coin flip with true 50/50 odds, both sides should be +100. At −110, you pay $10 juice per $100 won. Juice varies by market, book, and leg count. Soft books charge more juice; sharper books less. Some markets run at "even juice" (−110/−110) while others are shaded heavier on the popular side.
Worked Example
True probability both sides: 50%. Fair odds: +100. Actual posted: −110. Juice per bet: ($110 risk − $100 win) = $10 on every $100 won. Over 500 bets at $110 each, at 50% win rate: collect 250 wins × $100 = $25,000; lose 250 × $110 = $27,500. Net loss: $2,500 purely from juice. Win rate needed to overcome: 52.38%.
Why It Matters
Juice is unavoidable but negotiable — different books charge different rates. Moving from −110 to −105 on every bet reduces breakeven threshold by 1.16 percentage points across the full betting volume.