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 when 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're risking less with parlays, however they aren't. They believe they are able to win more with parlays, but they cannot. The bigger win with parlays is far outweighed by the bigger 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? Go ahead, make a parlay. We'll wait until both games are over, and in case there is a split we'll put the double bet on the loser. If your bookmaker sold you a parlay with that line, how many of you'll 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, dependant on whether the first game won or lost. That adds some luck to your betting it doesn't have to be there. The skilled handicapper is definitely wanting to make smart investments. He tries to eliminate the result of luck to the greatest extent possible in order to make his results as predictable as you possibly can.
Much like every rule, however, there are exceptions. The exception to the rule regarding parlays occurs when the two bets are co-dependent.
I knew one bookmaker who was simply taken for thousands because he didn't understand the co-dependency of certain bets. He allowed a player to consistently parlay the initial half with the overall game. The ball player parlayed totals by combining the over in the first 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 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 would lose $200.
Initially, this were a great opportunity for the book. The standard coin-flip odds of winning one parlay out of the two are 50-50. So far as the bookie was concerned the bettor should be winning $160 half enough 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 problem for the bookmaker was that both halves of each parlay were co-dependent. By the end of the initial 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 first half total was 27. By the end of the first half, the score was 31-21, for a complete of 52 first-half points. The first half of one of the parlays, the "over" in the first half was successful. For the parlay probability to be correct, there should now be considered a 50-50 probability of winning the "over" for the overall game. Obviously the chances of winning the "over" in the game weren't 50-50 but better than 99% in favor of the "over." The ball player only had a need to win the first 1 / 2 of the parlay to be virtually assured he would collect 2.6 times his money rather than just $10 for $11.
Before MB66 rush out to try this, be aware that most off-shore books are much too smart to let you parlay first half to game. If they do allow you to do this, start fretting about collecting because that book will be taken up to the cleaners.
There are, however, some less obvious co-dependent parlays that can still be made at many books. One kind 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 hardly any 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 even to create a potential win should 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 complete 46 �).
In the Virginia game, if you believe that Virginia covers the 25 points, they must hold Duke to only 11 points or the game will go over the total. The more likely it becomes during 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 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 probability of winning a parlay on Virginia and the over are higher than the standard 25%. Likewise, if the scoring stays low, it really is not as likely that Virginia covers the 25 points. Because of this, the probability a parlay of the under with the underdog will win is greater than the normal 25%.
For those who have no opinion on the 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 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 an absolute two-parlay spread.
The closer the posted total is to the spread on the side, the better win-rate will undoubtedly 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 would not allow such bets), but there is a sufficient co-dependency in the games with low totals and high spreads to make the strategy profitable long-term.
Not all bookmakers will allow you to parlay the side to the full total in the same game, because increasingly more are realizing these bets are occasionally co-dependent. But, enough books still do allow such bets for you to consider including such bets in your professional betting arsenal.
If your bookmaker provides "if/reverse" bets, it is possible to replace the parlay bet with an "if/reverse" bet and achieve greater success.