The general rule regarding parlays is: DON'T.
Parlays generally carry an increased house edge than straight bets, which means you give the book a more impressive advantage over you once you play them. That, by itself, is reason enough to suppress the misplaced feelings of greed combined with fear that often lead to betting parlays. People think they are risking less with parlays, however they aren't. They believe they can win more with parlays, however they cannot. The bigger win with parlays is far outweighed by the higher probability of losing. Parlay bettors are in fact risking more, with less possibility of collecting.
A parlay is not a single bet. It really is two bets -- a one-unit bet on one team and a two-unit bet on the other. Which team gets the two-unit bet? In point-spread betting at constant money odds, if both teams win or both teams lose it doesn't 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 can be bad money management. In a parlay you either bet double on the next team, or nothing on that same team, depending upon whether the first game won or lost. That adds an element of luck to your betting it doesn't have to be there. The skilled handicapper is always seeking to make smart investments. He tries to remove the result of luck to the greatest extent possible to make his results as predictable as possible.
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 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 game. The player parlayed totals by combining the over in the initial half with the over in the game, and the under in the initial half with under in the overall game. Both parlays were made in the same game. Every time the player won he'd win 2.6 times his bet. Betting $100 on each parlay, if one of them won, the 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.
Initially, this appeared to be a great chance for the book. The normal coin-flip probability of winning one parlay out of the two are 50-50. As far as the bookie was concerned the bettor should be winning $160 half the time, and losing $200 half enough time. The bettor, however, making $500 parlays, was ahead a lot 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. By the end of the initial half, the bettor was almost never in a 50-50 situation.
Take the Thursday night game between Utah and Air Force. The overall game total was 53 and the first half total was 27. By Fi88 Group of the first half, the score was 31-21, for a complete of 52 first-half points. The first half of among the parlays, the "over" in the first half was successful. For the parlay probability to be correct, there should now be a 50-50 possibility of winning the "over" for the 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 ball player only had a need to win the first half of the parlay to be virtually assured he would collect 2.6 times his money rather than just $10 for $11.
Before you rush out to try this, be aware that most off-shore books are much too smart to let you parlay first half to game. Should they do let you do this, start fretting about collecting because that book will be taken to the cleaners.
You can find, however, some less obvious co-dependent parlays that may still be made at many books. One kind of co-dependent parlay is the parlay of the side and total in the same game.
Any game in which the total is less than double the spread can provide you an advantage in parlaying side to total in the same game. We've already discussed, in a prior article, how exactly to use these anomalous side and total combinations to hedge one another and boost your win with very little increase in risk. Such a bet, however, needed that you have an opinion privately or the full total. Parlaying is another method to increase your potential win on these games, or even to create a potential win assuming you 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 believe that Virginia covers the 25 points, then they must hold Duke to no more than 11 points or the overall game will go over the full total. The more likely it becomes during the game that Virginia will cover 25 points, the more likely it becomes that the overall game will go over 48 �. The wider Virginia's winning margin, the much more likely the game will review. If you like Virginia to cover the spread, and you believe that Duke will never be shut out, then your probability of winning a parlay on Virginia and the over are greater than the standard 25%. Likewise, if the scoring stays low, it really is not as likely that Virginia will cover the 25 points. Therefore, the probability a parlay of the under with the underdog will win is higher than the normal 25%.
Should you have no opinion on the game, you can parlay the favorite 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 already won with the underdog for a winning two-parlay spread.
The closer the posted total would be to the spread on the side, the better win-rate will be on the parlay "spread" bet. The co-dependency in side to total parlays is not 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 help make the strategy profitable long-term.
Not all bookmakers will help you to parlay the medial side to the total in exactly the same game, because a lot more are realizing these bets are occasionally co-dependent. But, enough books still do allow such bets that you can consider including such bets in your professional betting arsenal.
If your bookmaker provides "if/reverse" bets, it is possible to replace the parlay bet having an "if/reverse" bet and achieve greater success.