Overround is the natural way to compare pricing quality across books and market types. Two-way game lines at sharp books commonly run 102–105%; multi-way markets run much higher - a 3-way soccer market or a golf outright can carry an overround well above 110%, which is why the same bankroll bleeds faster in exotic markets.
# Compute overround from any odds response overround = sum(implied(p) for p in market_prices) # -110/-110 -> 1.0476 (4.76% margin) # -105/-105 -> 1.0244 (2.44% margin, "reduced juice")
Every ParlayAPI odds payload contains the full per-book price set for a market, so overround is one line of arithmetic per book. Comparing overrounds is the quickest way to find which book is cheapest to bet into for a given market - the same comparison the best-line view makes across 45+ sportsbooks & sources.