Bet2Master

A single bet at minus 110 on a coin flip line costs 4.55% of the stake in expected value. Put two of those bets into a parlay and the cost is 8.88%. Four legs, 16.98%. Ten legs, 37.20%. The vig does not stay at one leg's worth when bets are combined. It compounds, and the reason is the same multiplication that makes the payout look attractive. The concept A parlay pays only if every leg wins. In exchange, its price is the product of the individual prices. At true odds pricing, which many US sportsbooks use for standard parlays, a two leg parlay at minus 110 and minus 110 pays the decimal price of one leg multiplied by the other. The vig is built into each of those decimal prices. Multiplying the prices multiplies the vig along with them. The formula Convert each leg to decimal first. For a negative American price: decimal = 1 + 100 / |American price| At minus 110, that is 1 + 100/110 = 1.9091. For a parlay of n legs at the same price, the parlay's decimal price is 1.90...

At −110, a bettor has to win 52.38% of bets just to finish level. Win exactly half, and a run of 100 such bets at $110 each ends $500 down, even though the record reads 50 wins and 50 losses. That 52.38% is the break even win rate, and it is simply the implied probability of the price read from the bettor's side. This piece shows how to calculate it for any line and why a .500 record is a losing record at standard prices. Concept: the price sets the bar Every price a sportsbook posts implies a probability. Read from the book's side, that number feeds the vig calculation. Read from the bettor's side, the same number answers a more personal question: how often would a bet at this price need to win for the money to come out even over many repetitions? The two readings are identical. The implied probability of a −110 line is 52.38%, and the break even win rate of a −110 bet is 52.38%. Nothing extra has to be calculated. What changes is how the number is used. Formula For ...

A standard −110/−110 line has an overround of 4.76%, but a sportsbook that takes equal money on both sides keeps 4.55% of what was bet, not 4.76%. Both numbers describe the same margin measured against different bases. State revenue reports then publish a third figure, actual hold, which can land far from either in any given month. This piece separates the three. Concept: one margin, three bases Overround is the amount by which a market's implied probabilities exceed 100%. It is measured against probability. Theoretical hold is the share of total money wagered that the book expects to keep if the line is priced as posted. It is measured against handle, the total amount bet. Actual hold , the figure in state revenue reports, is what the book kept after results were settled, divided by handle. It is measured against what actually happened. The first two are fixed by the price. The third depends on outcomes and on which bets customers chose. Formula For each side, implied pr...