About

Every betting market embeds a margin. The bookmaker sets odds so the sum of implied probabilities exceeds 1.0 (or 100%). That excess is the hold (also called overround, vig, or juice). A two-outcome market with fair odds would price both sides at 2.000 decimal. In practice, a typical book prices them at 1.909 / 1.909, producing a hold of roughly 4.8%. That percentage is the bookmaker's theoretical profit margin before variance. Failing to account for margin means you systematically overestimate your edge. A bettor placing 1000 wagers at 2% negative expected value loses approximately 20 units in the long run, regardless of short-term results.

This tool computes the hold from any set of odds, extracts the true (fair) probability for each outcome, and derives the no-vig line. It handles two-way, three-way, and markets with up to 12 selections. Note: the model assumes the margin is distributed proportionally across all outcomes. Some bookmakers apply asymmetric margins ("favourite-longshot bias"), which this proportional method does not capture. For Asian handicap or dynamic in-play lines, the displayed margin reflects the snapshot at time of entry only.

Formulas

Implied probability from decimal odds:

P_i = 1d_i

Bookmaker hold (overround):

Hold% = (n∑i=1 P_i − 1) × 100

True (no-vig) probability:

P_true = P_in∑j=1 P_j

Fair (no-vig) decimal odds:

d_fair = 1P_true

Expected value per unit staked:

EV = P_true × (d_i − 1) − (1 − P_true)

Where: P_i = implied probability of outcome i, d_i = decimal odds for outcome i, n = total number of outcomes in the market.

Reference Data

Market Type	Typical Hold Range	Example	Sharp Benchmark	Notes
NFL Sides (Spread)	4.5% - 5.0%	−110 / −110	1.5% - 2.5%	Standard US sportsbook
NFL Totals	4.5% - 5.0%	−110 / −110	2.0%	Same structure as sides
NFL Moneyline	3.0% - 6.0%	−150 / +130	1.5%	Varies with line disparity
Soccer 1X2	5.0% - 12.0%	2.10 / 3.40 / 3.50	2.0% - 3.0%	Three outcomes raise margin
Tennis Match	4.0% - 7.0%	1.50 / 2.60	1.5%	Two-way market
NBA Spread	4.5% - 5.0%	−110 / −110	2.0%	Standard juice
Horse Racing (8 runners)	15.0% - 25.0%	Various	5.0% - 8.0%	Multi-runner markets carry more margin
Golf Outrights (156 field)	20.0% - 40.0%	Various	8.0% - 12.0%	Large fields inflate overround
Prop Bets (Yes/No)	5.0% - 10.0%	−120 / +100	3.0%	Soft markets with wide margins
Parlay / Accumulator	10.0% - 30.0%	Compound	N/A	Margin compounds per leg
Live / In-Play Spread	5.0% - 8.0%	Dynamic	3.0%	Higher margin for speed premium
Esports Match Winner	4.0% - 8.0%	1.60 / 2.30	2.0%	Varies heavily by book
Pinnacle Benchmark (Sides)	1.5% - 2.5%	−104 / −104	-	Industry-low margin reference
Betfair Exchange (pre-commission)	0.5% - 2.0%	Back/Lay spread	-	Commission applies separately

Frequently Asked Questions

In a parlay, the effective margin compounds multiplicatively. For a 2-leg parlay where each leg carries a hold of 4.5%, the combined overround approximates (1.045)² − 1 ≈ 9.2%. A 5-leg parlay at 4.5% per leg yields roughly 24.6% effective margin. This is why parlays are structurally disadvantageous regardless of individual leg quality.

They refer to the same concept measured slightly differently. Overround is the raw excess of summed implied probabilities over 100%. Hold is the same value expressed as the bookmaker's theoretical take. Vig (vigorish) and juice are colloquial US terms for the same margin. A market priced at −110/−110 has implied probabilities of 52.38% + 52.38% = 104.76%, so the overround is 4.76% and the hold is 4.76%.

Not necessarily. A sharp book with 2% hold and accurate lines can offer worse EV than a soft book with 5% hold and inaccurate lines, if you can identify the inaccuracy. However, for bettors without an edge model, lower hold strictly reduces the rate of expected loss. Pinnacle's 1.5-2.5% hold on major markets is the industry standard for low-margin pricing.

For negative American odds (e.g., −150): P = |odds| / (|odds| + 100) = 150/250 = 60%. For positive American odds (e.g., +130): P = 100 / (odds + 100) = 100/230 ≈ 43.48%. The sum of implied probabilities for all outcomes in the market will exceed 100% by the margin amount.

The proportional method assumes the bookmaker distributes margin equally across all outcomes relative to their probability. In practice, many books apply more margin to longshots (favourite-longshot bias). A 50/1 longshot might carry 8-15% margin while the corresponding favourite carries only 1-2%. Advanced methods like Shin's model or the power method attempt to account for this asymmetry, but require additional assumptions about insider trading proportion.

For two-outcome markets (spreads, totals), target books offering hold below 3.0%. The sharpest exchanges and books operate at 1.5-2.5%. For three-way markets (soccer 1X2), hold below 4.0% is competitive. Any two-way market above 6.0% hold is significantly overpriced. Use this calculator to compare the same market across books; the difference in margin directly impacts your long-term return.