The general rule regarding parlays is: DON'T.
Parlays generally carry a higher house edge than straight bets, which means you give the book a bigger advantage over you when you play them. That, alone, is reason enough to suppress the misplaced feelings of greed coupled with fear that often result in betting parlays. People think they're risking less with parlays, but they are not. They believe they are able to win more with parlays, but they cannot. The higher win with parlays is far outweighed by the higher probability of losing. Parlay bettors are actually risking more, with less probability of collecting.
A parlay is not a single bet. It is two bets -- a one-unit bet using one team and a two-unit bet on another. Which team gets the two-unit bet? In point-spread betting at constant money odds, if both teams win or both teams lose no matter which team gets the double bet. When one team wins and one team loses, however, the double bet is presumed to have been on the loser. How smart is that for the bettor? Just do it, make a parlay. We'll wait until both games are over, and in case of a split we'll put the double bet on the loser. If your bookmaker sold you a parlay with that line, just how many of you would still make the bet?
A parlay is also bad money management. In a parlay you either bet double on the next team, or nothing on that same team, dependant on if the first game won or lost. That adds some luck to your betting it doesn't have to be there. The skilled handicapper is always wanting to make smart investments. He tries to get rid of the effect of luck to the greatest extent possible to make his results as predictable as you possibly can.
As with every rule, however, there are exceptions. The exception to the rule regarding parlays occurs once the two bets are co-dependent.
I knew one bookmaker who was taken for tens of thousands because he didn't understand the co-dependency of certain bets. He allowed a new player to consistently parlay the first half with the overall game. The player parlayed totals by combining the over in the initial half with the over in the overall game, and the under in the initial half with under in the game. Both parlays were made in the same game. Each time the player won he would win 2.6 times his bet. Betting $100 on each parlay, if one of these won, the ball player would win $260 and lose $100 on another parlay for a net win of $160. He could never win both parlays. If he lost both parlays he'd lose $200.
At first glance, this appeared to be a great chance of the book. The normal coin-flip probability of winning one parlay out from the two are 50-50. So far as the bookie was concerned the bettor should be winning $160 half the time, and losing $200 half the time. The bettor, however, making $500 parlays, was ahead more than $20,000 after six months, and the book begun to look at what the bettor was doing more carefully.
The issue for the bookmaker was that both halves of every parlay were co-dependent. At the end of the first half, the bettor was hardly ever in a 50-50 situation.
Take the Thursday night game between Utah and Air Force. The overall game total was 53 and the initial half total was 27. By the end of the initial half, the score was 31-21, for a complete of 52 first-half points. The first half of one of many parlays, the "over" in the initial half was successful. For the parlay probability to be correct, there should now be considered a 50-50 possibility of winning the "over" for the overall game. Obviously the chances of winning the "over" in the game weren't 50-50 but much better than 99% in favor of the "over." The player only needed to win the first 1 / 2 of the parlay to be virtually assured that he would collect 2.6 times his money instead of just $10 for $11.
Before you rush out to use this, be aware that most off-shore books are much too smart to enable you to parlay first half to game. If they do let you do this, start worrying about collecting because that book will soon be taken up to the cleaners.
There are, however, game hit club -dependent parlays that may be made at many books. One type of co-dependent parlay may be the parlay of the medial side and total in the same game.
Any game in which the total is significantly less than double the spread can provide you an edge in parlaying side to total in exactly the same game. We've already discussed, in a prior article, how to use these anomalous side and total combinations to hedge one another and boost your win with very little increase in risk. This type of bet, however, required that you have an opinion privately or the full total. Parlaying is another method to increase your potential win on these games, or to create a potential win for those who have no opinion.
You can find two games this Saturday that qualify. They are Virigina -25 over Duke with a total of 48 �, and Kansas St. -24 � vs. North Texas with a total 46 �).
In the Virginia game, if you were to think that Virginia will cover the 25 points, then they must hold Duke to only 11 points or the game will go over the full total. The much more likely it becomes through the game that Virginia will cover 25 points, the more likely it becomes that the game will go over 48 �. The wider Virginia's winning margin, the much more likely the game will go over. If you like Virginia to cover the spread, and you believe that Duke will never be shut out, then your possibility of winning a parlay on Virginia and the over are greater than the standard 25%. Likewise, if the scoring stays low, it is less likely that Virginia will cover the 25 points. Due to this fact, the probability that a parlay of the under with the underdog will win is higher than the normal 25%.
Assuming you have no opinion on the overall game, you can parlay the favourite with the "over" and the underdog with the "under" and collect sufficiently often to exceed the losses when both parlays lose. In the only real other game meeting the qualifications this week -- Friday's game between California -30 against New Mexico State with a complete of 58 -- the under has recently won with the underdog for a winning two-parlay spread.
The closer the posted total would be to the spread privately, the better win-rate will undoubtedly be on the parlay "spread" bet. The co-dependency in side to total parlays isn't as strong as parlaying first half and game totals (if it were, most books wouldn't normally allow such bets), but you will find a sufficient co-dependency in the games with low totals and high spreads to make the strategy profitable long-term.
Not all bookmakers will help you to parlay the side to the total in the same game, because an increasing number of are realizing these bets are occasionally co-dependent. But, enough books still do allow such bets that you should consider including such bets in your professional betting arsenal.
If your bookmaker provides "if/reverse" bets, you can replace the parlay bet with an "if/reverse" bet and achieve greater success.