At most sportsbooks, bettors have the option of “buying points” on certain sports, which entails accepting worse odds in exchange for a better line. This option is typically available on sports like football and basketball-sides and totals-but not sports like baseball and hockey.Generally, you are charged 10 “cents” for each half point move, with a cap on how many points are allowed. Which is to say if the odds on your game are the standard -110, you can move the line a half point in your favor if you’re willing to bet at -120 instead, a full point if you’re willing to bet at -130, etc.

So let’s say the total on the Bulls-Knicks game is 188 at a sportsbook that charges -110 for straight bets, and you are interested in betting $50 on the Over. You can bet Over 188 at -110 of course, meaning you’d put up $55 to win $50. But by buying points, if you preferred you could also bet Over 187.5 at -120 risking $60 to win $50, Over 187 at -130 risking $65 to win $50, Over 186.5 at -140 risking $70 to win $50, etc.

So when, if ever, is it a good idea to buy points like this?

How much a point is worth depends on how likely the game is to land on that point. The best evidence to use in estimating this probability is generally historical data for that sport. So if you want to know how much better Over 187.5 is than Over 188 for that Bulls-Knicks game, you’d want to find out how often exactly 188 points are scored in NBA games. In fact, within that data you’d probably want to look only at games with lines close to 188, or at least give those games more weight, because you’re really not so interested in how often games projected to score 220 or 230 land on 188.

Once you’ve gotten an estimate of how often a game will land on a certain number, you can calculate if it’s worth buying points around that number. In the above example, if it turns out there is a 3% chance of your game landing right on 188, then 3% of the time moving that half point from 188 to 187.5 is going to change a tie to a win for you. But of course about half the time (if you’re a good handicapper a little less than half the time) in those other 97% of the cases, you’re going to lose, and those losses will be at -120 instead of -110 if you move the line that half point. If you do the math, you’ll see that in the long run, converting 3% of ties to wins will not make up for the worse odds you’re betting into, so it would not be worth buying the half point here.

It’s worth running the numbers to find out for yourself, but I doubt you’ll find any points-on sides or totals-that land often enough to be worth buying in basketball. Same with college football. Same with totals in the NFL. About the only promising area you might want to look at would be NFL sides, as games tend to land on a few “key numbers” more often in the NFL than in college.

A complication here though is that sportsbooks know the ‘3’ is particularly common in football (i.e., games are often decided by exactly 3 points), so that’s the one exception they make in how they charge for half points. In order to move a line on or off the ‘3’ (i.e., buy it from -3.5 to -3, or from -3 to -2.5, or from +2.5 to +3, or from +3 to +3.5), instead of charging 10 cents, sportsbooks typically charge 20 cents. So if the line on the underdog is +2.5, -110, you’d have to pay -130 to get +3 (and -150 to get +3.5).

Most people who have run the numbers on the NFL have concluded that the ‘7’ is worth about 10 or 11 cents, and the ’10’ is worth about 10 cents, so buying on or off the ‘7’ or ’10’ at the standard rate of 10 cents per half point is probably not going to help you or hurt you much if at all. And the ‘3’ is worth maybe 20-22 cents, so buying on or off the ‘3’ at the standard rate of 20 cents per half point is probably about break even or very slightly advantageous. All other points are clearly worth less than 10 cents and you’re just hurting yourself in the long run by buying points.

So buying points will rarely help you, and when it does it’ll help you only very little. (The exception being if you come across a special promotion, like a sportsbook allowing you to buy on and off the ‘3’ in the NFL for 10 cents or 15 cents.) Furthermore, even where it helps slightly, it may still not be your best option. If you see +7, -110 at a sportsbook, then even if you’d be equally or better off buying a half point and betting +7.5, -120, you might well be able to shop enough other sportsbooks to find +7.5, -110 or +7.5, -115 without having to buy points. Or if, say, you are contemplating whether to buy points to change your +2.5, -110 bet to +3, -130 or +3.5, -150, it may be that putting that game into a 6 point teaser and taking it to +8.5 is better than any of these options.

In my opinion, the option of buying points is one of the least valuable weapons to have in your arsenal. Once in awhile it will help you a tiny bit, but that’s about it.

Actually the main function of this option is to tempt squares into losing more money. Few people who buy points base their decisions on crunching the numbers and knowing the value of each half point move. Instead they’re influenced by psychological factors. The most common is “I hate to lose by a half point.” So if the line is -14.5, they’ll always buy it to -14. That way if they lose at all it’ll always be by a full point or more; they can’t lose by a half point.

Or another one would be if they see there’s a better line available at one or more other sportsbooks, but they don’t have an account at any of them, then they’ll buy the half point at their sportsbook so they’re still getting “the best line.” Or if the line was a half point or a point better earlier in the week before they were ready to pull the trigger, they’ll buy a half point or a point now to get back to that line so they don’t have to feel like they missed it.

All of which is basically throwing money away. The half point move is worth what it’s worth, and that doesn’t change because you’re playing psychological games with yourself. You might find it more frustrating to lose by a half point, or to lose a bet that you could have won if you’d bet it at a different sportsbook or earlier in the week at a different line, but that’s utterly irrelevant to your bottom line.

My advice for beginning and even most intermediate players would be to simply ignore the option of buying points entirely. For more advanced players, crunch the numbers, find the very infrequent occasions where it helps you marginally to buy a half point or more, and feel free to use the option there.