Knowing When to Buy Points on NFL Lines in 2021

Increase your long-term NFL betting profitability with smart point-buying strategies.

Last Updated: Sep 17, 2021 11:44 AM ET Read Time: 4 min
Las Vegas Raiders wide receiver Bryan Edwards (89) is stopped short of the goal line by Baltimore Ravens cornerback Brandon Stephens (21) during overtime at Allegiant Stadium.
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Many sportsbooks offer bettors a chance at picking up an extra half-point on a spread for greater reward, but the juice is always in the books’ favor. We’ll teach you how to shop smart with practical examples.

Point-buying strategy at a glance

• Buying points is an option many books allow, and many bettors opt for

• Most bettors don’t know the actual mathematical implications of laying the juice

• Simple techniques help find fair value prices and increase long term profitability

It’s ten minutes before NFL kickoff, and it’s now time to place your favorite bet of the weekend. You pride yourself in being an above-average bettor, one certainly better than the casual betting friends of yours that let bets fly on a whim and hope to cash out big on ten-team parlays every weekend. 

You’ve done your fair share of reading, research, and even some data analysis to sharpen your game and become a +EV bettor. You stare down the odds of your favorite bet of the day’s NFL lines, and you see the following options.

Team Spread Odds
Sports Team +2.5 +105
Sports Team +3.0 -120

Flashbacks of seemingly every bet you’ve ever lost by that exact hook play through your head. “No, not again. Not this time,” you tell yourself. Seconds later, the screen reads, “Bet accepted: Team +3.0 -120.”

Three hours later Sports Team has comfortably lost the game by two touchdowns. Like the uncountable amount of unnoticed times before, the hook never even became a factor, and as a result, you don’t even remember to reflect on the decision to buy the half point. 

So here is your wake-up call and a chance to reflect and learn. When should you buy that half-point?

Spreads

If we think about it intuitively, the amount of juice we should pay to buy points should reflect the frequency at which that particular margin happens. To illustrate that, here’s an example using the king of key numbers: three. 

Let’s say we want to look at the merit of buying a half-point from +2.5 to +3.0. From our key numbers article, we know that since 1995 games have landed on three around 15.2 percent of the time. However, we need to split that frequency in half since we’re talking only about teams losing by three and not just all margins of three (which would include winning by three), so that leaves us with 7.6 percent. 

Then we have to split that frequency in half again since spreads are offered in half-point increments while actual game margins are in full points. We divide the frequency of losing by three into the two spreads of +3.0 (a push) and +3.5 (a win). That leaves us with 3.8 percent for each. 

For this example, let’s bring back in the fake point spread examples from earlier: 

Team Spread Odds
Sports Team +2.5 +105
Sports Team +3.0 -120

Using an odds converter, we can convert +105 into the implied probability of 48.78 percent. Using the math we determined earlier, add our 3.8 percent push probability to get 52.58 percent. Using the odds converter inversely, we know that a 52.58 percent probability is equivalent to -111 in American odds. This price is the maximum price you should pay in this example to go from +2.5 to +3.0. This means the earlier decision to pay -120 for the +3.0 was inefficient and will cost us in the long run. 

So to review, the process to determine the max price you should pay to add a half-point to a spread is:

1

Convert the odds of the original wager to an implied probability percentage.

2

Divide the frequency of that number in half twice (aka by four).

3

Add that percent to the implied probability percentage.

4

Convert that new percentage into odds.

5

Compare those odds to the odds of buying a half-point.

To spare you the manual work below is a fair value chart for spreads through 10.5 with 14.0 and 14.5 added on as well. The prices listed are in relation to -110 odds on the original spread, and when reading this table, the spread in the left column is the spread you are considering buying points towards. For example, if you are considering purchasing a half-point from -3.5 (-110) to -3.0, you would look at the row with -3.0 and see that the fair price for buying that point is -128. 

Underdog Frequency Fair value Favorite Frequency Fair value
1.0 1.02% -115 -1.0 1.02% -115
1.5 1.02% -115 -1.5 0.93% -114
2.0 0.93% -114 -2.0 0.93% -114
2.5 0.93% -114 -2.5 3.80% -128
3.0 3.80% -128 -3.0 3.80% -128
3.5 3.80% -128 -3.5 1.21% -115
4.0 1.21% -115 -4.0 1.21% -115
4.5 1.21% -115 -4.5 0.86% -114
5.0 0.86% -114 -5.0 0.86% -114
5.5 0.86% -114 -5.5 1.45% -117
6.0 1.45% -117 -6.0 1.45% -117
6.5 1.45% -117 -6.5 2.32% -121
7.0 2.32% -121 -7.0 2.32% -121
7.5 2.32% -121 -7.5 0.89% -114
8.0 0.89% -114 -8.0 0.89% -114
8.5 0.89% -114 -8.5 0.41% -112
9.0 0.41% -112 -9.0 0.41% -112
9.5 0.41% -112 -9.5 1.46% -117
10.0 1.46% -117 -10.0 1.46% -117
10.5 1.46% -117 -10.5 1.23% -116
14.0 1.23% -116 -14.0 1.23% -116
14.5 1.23% -116 -14.5 0.38% -112

Totals

The same ideas and execution apply to NFL totals as well, with just one caveat. Since totals don’t have a positive and negative equivalent like margins, you only have to divide the frequency in half once. So instead, the process looks like this:

  • Convert the odds of the original wager to an implied probability percentage
  • Divide the frequency of that number in half
  • Add that percent to the implied probability percentage
  • Convert that new percentage into odds
  • Compare those odds to the odds of buying a half-point

You can use the chart below as a reference for frequency in totals.

Conclusion

So there you have it. Knowing your fair value price for buying points is one way to increase your profitability over the long term. You can apply these same techniques to selling points to further improve your profitability. Furthermore, these techniques are even applicable to alternative spreads and totals, which can broaden your football betting horizon even more. Either way, you now have another tool in your arsenal to become a better bettor.

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