|
|
|
The Mathematics of Sports Betting
Don't make sucker bets - see how the house holds an advantage for certain types of wagers
The house edge for parlays:
In general, each wager has a 50% or ½ probability of winning. If we are trying to determine the probability
of hitting multiple bets, we just multiply ½ by the number of bets we are making. The probability of hitting
a two team parlay is ½ by ½ = ¼. Another way to express this is to way that we will lose 3 times for each
time that we win. Still another way to express this is to say that the fair odds are 3-1. A normal payout
for a two team parlay is 13-5. Assuming a $5 wager, we can calculate the house edge as follows.
Expectation = [1/4 x (+13)] + [3/4 x (-5)]= -2/4= -0.5
E per $1 bet = -0.5/5 = -0.10, or 10% house advantage
For a six team parlay, the true probability of winning is ½ x ½ x ½ x ½ x ½ x ½ = 1/64. This means that we
can expect to lose 63 times for each time that we win (fair odds of 63-1). If the casino pays out at 44-1
odds (typical payout), the house edge for the bet is:
E=[1/64 x (+44)] + [63/64 x (-1)] = -19/64 = -0.297, or 29.7% house advantage
The house edge for straight bets:
Assuming the same 50% win probability as for parlays and using an $11 bet (the house pays 10-11 on straight
wagers), we can confirm the house edge.
Expectation=[0.5 x (+10)] + [0.5 x (-11)]= -0.5
E per $1 bet = -0.5/11 = -0.045, or 4.5% house advantage
Overcoming the house advantage for straight bets:
Straight bets are made risking $11 to win $10. To overcome the house advantage you will have to win 11
times for every 10 times you lose.
[10 x (-11)] + [11 x (+10)] = 0
An easier way to express this is to say that you have to win 11 out of 21 bets, 11/21=0.5238, or 6=52.4%
to break even.
|
|
| |
|
|
|
|
This site is protected under both U.S. copyright law and international
treaties. No part of this website, including text, layout or images, may be reproduced or copied in any form or by any method.
Powered by @tomic Studio
|