NOTE: Since the NFL added a 17th regular season game for the 2021 season, we’ve adjusted all metric totals involving the 2021 season down to a 16-game total.
For years, the NFL key numbers of three and seven have gotten sacred treatment from bettors. And while they remain essential spread-betting numbers, they aren’t as important as they used to be.
Key numbers at a glance
• Teams have since attempted and made fewer extra points
• Margin frequencies (especially around key numbers) have changed as a result
Ahead of the 2015 season, the NFL moved the extra point back from the two-yard line to the 15-yard line, effectively making the extra-point attempt go from a 20-yard try to a 33-yard one. The move came on the heels of five straight seasons of 99%-plus success rates, and a stretch spanning from 1988 during which the extra-point conversion rate never dipped below 97%.
The change led many savvy bettors to believe that the previous rigidity of NFL’s key numbers would budge as more extra-point attempts would miss and more teams would be inclined to go for two.
With nine seasons of data under our belt since the change, let’s see if the theory held and what kind of effect (if any) it had on key numbers. We’ll look at the nine seasons since the change vs. the nine seasons before the transition to keep sample sizes equal for this examination.
Extra-point attempts and success rate
So first off, did the change lead to a decrease in conversion rate? Extra points converted at a 99.2% rate in the nine years before the shift. In the nine seasons since the change, extra point attempts have dipped to a 94.1% conversion rate - a 5.1% difference.
Despite moving the attempt back, the number of attempts has remained steady: 4.7 total extra-point attempts per game. The dip in conversion rate across those two timeframes, however, means that the expected points from extra-point attempts in an NFL game have dropped from 4.66 to 4.42. That 0.24-point dip in scoring just from extra-point attempts may not seem like much at first, but the impact is easier to contextualize when comparing that dip to the juice you pay to buy just a half-point.
So if extra-point attempts are more difficult, teams should be discouraged from attempting them as often, right? Let’s take a look.
- In the nine seasons before the change (2006-2014), teams averaged 2.35 extra-point attempts per game
- In the nine seasons following the change (2015-2023), teams have averaged 2.33 attempts per game
- In 2020, teams set the record for most extra-point attempts in league history (1,338), with 2021 notching the third-highest attempts (1,257) in league history
So what gives?
Many NFL fans and bettors know there was an offensive boom from around 2015 to 2021. With more touchdowns, teams naturally have more opportunities to kick the extra point. Therefore we should be looking at the rate at which teams opt to kick the extra point compared to going for two, not raw totals.
From 2006 to 2014 teams opted to kick the extra point following 95.2% of touchdowns; from 2015 to 2023 they opted to kick just 90.7% of the time. In 2021 alone the attempt rate dipped to an all-time low of 88.3%, and in 2023 the attempt rate dropped to below 90% for just the third time in league history.
Margin of victory in the NFL since 2015
So now we know that:
- Teams are choosing to kick the extra point with less frequency.
- They are kicking them with less success.
So if the previously “perfect” seven-point touchdowns of the past are less likely to happen, are we seeing the distribution of winning margins change? Since the rule change, we’ve seen a collective 2.4% increase in six and eight-point games in the nine seasons since the extra-point rule change compared to the nine seasons prior to the rule change
Although that might seem small within the context of the ~5% decrease in extra-point success rate, you have to keep in mind that missed extra points aren’t ultimately final as teams have the rest of the game to try and make up for it with two-point attempts.
With that in mind, it intuitively makes sense for the six- and eight-point frequency increase (2.4%) to be slightly less than half the extra-point success decrease (~5%) as two-point attempts convert at about that rate.
There is noticeably one unexpected increase in margin frequency: five-point games (+1.4%). There aren’t any immediate reasons strictly related to extra-point frequency due to the rule change that could explain the trend. It would be easy to mark it as just a sample size issue for 2015-2023.
But one logical explanation could be the increased availability and usage of data-driven insight on when it is logical to go for two and when it’s not. And the proliferation of that information makes it easy for beat writers, analysts, and fans to bombard coaches with criticism when they bungle those opportunities.
Regarding five-point games: A team leading by five after a touchdown improves its win probability by 3.1% by kicking an extra point and making it a six-point game versus improving its win probability by 5.2% by successfully converting a two-point conversion and making it a full touchdown game. Conversely, a team down five after scoring a touchdown improves its win probability by 2.9% when adding an extra point and making it a four-point game versus 5.0% when converting a two-point try and making it a field-goal game (probabilities via FiveThirtyEight).
Those two situations make up the third- and fourth-largest improvements in win probability when converting a two-point conversion instead of an extra point. This manifests in the (relatively) significant jump in five-point margins. It is the only instance in which it is significantly beneficial to attempt a two-point conversion when trailing and leading by the same number.
Interesting five-point tangents aside, what are the essential takeaways for NFL key numbers for spreads in 2022?
Ultimately three and seven are still king, and 10 and 14 also matter when looking at the (more infrequent) larger point spreads.
Outside of that, six and eight (especially six) are just a little easier to swallow if the alternative is paying large juice on a seven.
NFL totals since 2015
Totals have shifted a lot in the last 25 years. In the 12 seasons from 2000 to 2011, the average total was 41.8. And then from 2012 to 2020, totals steadily rose to a ten-year average of 45.7 - a near 10% increase. That included an all-time high average total of 48.1 in 2020.
Then scoring took a turn. The 2021 season saw a 46.5 total that was still high, but the average total finished above average per game scoring for just the third time since 2000. Then it happened again in 2022 (average total of 44.2 vs 44.0 points per game), and 2023 finally saw the return of scoring (43.8 points per game) outpacing totals (43.1) once again - but just barely.
A large reason for that reverse of course has been the popularization of two-high safety shells, which limit the deep ball and force teams to opt for shorter passes and to lean more heavily on the run game against less stacked boxes.
So how has this affected key numbers in totals, if at all? It’s a tricky question, as “key numbers” in totals are nowhere near as rigid or frequent as they are in spreads.
For example, the key number of three in spreads occurs in around 15% of all games and seven in about 9%. In comparison, the most frequent total numbers appear about 4% of the time. Because the peak frequency of key numbers in totals is so low, the relative gaps between those frequencies and the least frequent numbers are not as significant.
For example, the key number of three in spreads occurs about 10% more frequently than the least frequent one-score margins, and seven is still 5% more frequent than those numbers. The most frequent key numbers in totals only happen around 3% more often than the less frequent numbers, illustrated below.
|
Points
|
2004-2013 | 2014-2023 | Change |
|---|---|---|---|
| <35 | 26.8% | 22.1% | -4.7% |
| 35 | 1.5% | 1.6% | 0.1% |
| 36 | 2.1% | 2.7% | 0.6% |
| 37 | 3.8% | 3.6% | -0.3% |
| 38 | 2.1% | 1.7% | -0.4% |
| 39 | 1.7% | 2.4% | 0.7% |
| 40 | 3.5% | 3.7% | 0.3% |
| 41 | 3.9% | 3.5% | -0.4% |
| 42 | 1.4% | 1.7% | 0.3% |
| 43 | 3.7% | 3.2% | -0.5% |
| 44 | 4.1% | 3.7% | -0.4% |
| 45 | 2.9% | 2.5% | -0.4% |
| 46 | 1.5% | 2.3% | 0.8% |
| 47 | 3.2% | 3.1% | -0.2% |
| 48 | 3.3% | 2.7% | -0.6% |
| 49 | 1.7% | 2.2% | 0.5% |
| 50 | 2.2% | 2.7% | 0.5% |
| 51 | 3.6% | 3.9% | 0.3% |
| 52 | 2.3% | 2.1% | -0..2% |
| 53 | 1.7% | 1.3% | -0.40% |
| 54 | 1.8% | 2.3% | 0.5% |
| 55 | 2.4% | 2.6% | 0.3% |
| 56 | 0.6% | 1.1% | 0.5% |
| 57 | 1.8% | 2.2% | 0.4% |
| 58 | 2.1% | 1.9% | -0.2% |
| 59 | 1.3% | 1.4% | 0.2% |
| 60+ | 12.9% | 15.8% | 2.9% |
As you can see, the “key numbers” in totals are primarily “key ranges.” When looking at the last ten seasons (2014-2023) you can see this with 36-37, 39-41, and then a wide-spanning range of 43-51, and then 54-55. With the recent boom in scoring, you can see in the far right column that this has shifted scoring frequencies towards the higher numbers.
So when it comes to totals, the key takeaway is that although there are certainly more frequented totals in the form of some “key ranges,” they aren’t anywhere near as firm as key numbers in spreads.
However, it is always advantageous to still play the probabilities, meaning you’d prefer to be above these ranges when playing the Under and below them when playing the Over. On top of that, there are other game elements to consider when playing totals such as the weather.
Smart NFL betting strategies
How Weather Affects Your NFL Betting
Key Advanced Metrics and Stats to Add to Your NFL Betting Process
Knowing When to Buy Points on NFL Lines in 2023
NFL Teaser Strategies For 2023
How Turnover Margin Affects Win Probability and Win Totals in the NFL
What NFL Bettors Need To Know About Home-Field Advantage in 2023
NFL key numbers FAQs
Key numbers in NFL betting revolve around the most frequent deciding margins in games. Three and seven are the most frequent of all due to the rigid scoring system of the NFL.
Because of how points are scored in the NFL, bettors can use this knowledge to predict the margins in football games.
Despite rule changes in the NFL, traditional key numbers are still by far the most dominant in NFL margins.
In American football betting, the "key numbers" often considered the best to bet on are 3, 7 and 10, as those often represent the margin of victory due to the sport's scoring structure. Betting with these numbers in mind might provide an advantage. However, betting always involves risk, so it's important to bet responsibly.
