Buying the half point is a popular play amongst sports bettors, especially when it comes to spreads of 7 and 3. The slang for this is “buying the hook,” the hook being the half point that supposedly hooks the game more in your favor. It’s a pretty simple concept, and at first look it even makes a lot of sense. The outcome of a game being decided by a single scoring drive is pretty common—but is it common enough to warrant doubling the juice that the book is charging you? To figure this out, we need to look at some math.
The cost of changing the spread from 7.5 to 7 is ten cents. Instead of having to win by 8 or more points, the favorite can win by 7 points and a draw will be declared where your bet is refunded to you without any loss by either party. This seems attractive, but is the possibility of a draw really worth a sacrifice in the line? The answer here is no—the sacrifice is too much for too small of a concession by the book. A line of -110 is what you’re starting out with, and when you get the half point in your favor, the line becomes -120. In theory, you would be needing to increase your edge by 2.1 percent since a -110 line’s breakeven point is 52.4 percent and a -120 line has a breakeven point of 54.5 percent. Not a huge difference, but is a half point swing really going to make up this ground?
The truth is that many more games will end with the half point having absolutely no effect than they will end in the very narrow range that you are creating. If you buy the line down from 3.5 to 3, and the favorite wins by just 2, you’re still a loser. And if they do win by three points, you’re still not winning anything—you’re just not losing.
Based upon a 19 year sample (1990 into 2008), home teams with a -3.5 spread covered their assigned handicapped spread about 62.8 percent of the time, or a total win/loss record of 181-107. Over the same timeframe, -3.0 spreads for home teams were covered 255 out of 418 times (255-163), or only 61.0 percent of the time. In other words, the difference is negligible at best, and the sportsbook has a clear cut advantage here if this 20 year data sampling is indicative of the overall trend. You would expect the spread covering action to increase as the spread got smaller, but over this small of a sample size, only the number of samples went up, the percentage covered actually dropped a little bit. This should indicate that if you are trying to buy a half point in this range, there is very little mathematical evidence to suggest that it is truly worthwhile for you. Instead of gaining that 2.1 percent edge that you need, you’re actually losing 1.8 percent, making buying the half point a long term losing wager.
The alternative to buying the half point is to capitalize on teasers. Instead of 0.5 of a point, you are taking the game and skewing it 6 points in your favor. The downside to a teaser is that you must select multiple games to tease out, and this will inevitably make your win percentage go down, but from a purely mathematical standpoint, altering two games by 6 points each is easier than changing the outcome of one game by 0.5. Teasers are a completely different topic, but they do hold promise if you are looking to bet on three or more different games.