CRAZY NBA FACTS FROM THE LAST 14 SEASONS!!!
This 6-article series presents some crazy and interesting findings from all NBA games over the last 14 seasons (from 2002/2003 to 2015/2016).
Today we answer question #6 (the final one!):
Over the past 14 NBA seasons, what are comeback probabilities through quarters 1-2-3?
Have you ever wondered, as you were watching an NBA game, what were the chances that the team currently trailing by “x” points would come back to win the game? It’s an interesting question to any casual basketball fan, and certainly one that is relevant to people betting on “live” (or “in-play”) NBA lines. This form of gambling called “live betting” or “in-play betting” has completely revolutionized the online world and its popularity is booming. It basically allows people to place wagers DURING games.
For example, what is the probability that the home team trailing by 6 points after one quarter will make a comeback? Take a guess! 25%? 35%? 45%? Let’s dive into the numbers from the last 14 NBA seasons. Here are the numbers of wins and losses by the home team when it was trailing by “x” points after quarters 1, 2 and 3:
Road team’s lead | Through quarter #1 | Through quarter #2 | Through quarter #3 |
2 | 451-421 (51.7%) | 318-273 (53.8%) | 231-276 (45.6%) |
4 | 325-392 (45.3%) | 244-276 (46.9%) | 172-307 (35.9%) |
6 | 250-353 (41.5%) | 190-329 (36.6%) | 124-304 (29.0%) |
8 | 180-274 (39.6%) | 129-298 (30.2%) | 77-310 (19.9%) |
10 | 103-186 (35.6%) | 79-254 (23.7%) | 39-263 (12.9%) |
12 | 63-137 (31.5%) | 54-204 (20.9%) | 14-227 (5.8%) |
14 | 20-100 (16.7%) | 33-192 (14.7%) | 12-182 (6.2%) |
16 | 17-54 (23.9%) | 15-108 (12.2%) | 6-161 (3.6%) |
18 | 5-29 (14.7%) | 8-94 (7.8%) | 2-134 (1.5%) |
20 | 3-13 (18.8%) | 4-43 (8.5%) | 1-81 (1.2%) |
Based on the numbers from this table, the answer to our previous question is: a home team trailing by 6 points after one quarter has approximately a 41.5% chance of coming back to win the game. Did you guess right?
It is interesting to note that the home team still has more than a 50% chance of winning despite trailing by 2 points after one or two quarters of play. However, that probability goes down to 45.6% after three quarters. Also, home fans should not lose hope when their team trails by as much as 12 points after the 1st quarter: according to the numbers above, they still hold more than a 30% chance of prevailing!
How about the road team’s comeback probabilities? Let’s look at the numbers:
Home team’s lead | Through quarter #1 | Through quarter #2 | Through quarter #3 |
2 | 356-552 (39.2%) | 258-425 (37.8%) | 200-360 (35.7%) |
4 | 225-547 (29.1%) | 219-455 (32.5%) | 145-410 (26.1%) |
6 | 215-514 (29.5%) | 165-449 (26.9%) | 133-441 (23.2%) |
8 | 138-435 (24.1%) | 117-424 (21.6%) | 76-435 (14.9%) |
10 | 79-359 (18.0%) | 71-459 (13.4%) | 52-417 (11.1%) |
12 | 59-241 (19.7%) | 41-327 (11.1%) | 17-374 (4.3%) |
14 | 19-175 (9.8%) | 29-277 (9.5%) | 8-318 (2.5%) |
16 | 14-111 (11.2%) | 17-185 (8.4%) | 8-291 (2.7%) |
18 | 5-72 (6.5%) | 11-194 (5.4%) | 2-235 (0.8%) |
20 | 1-31 (3.1%) | 2-109 (1.8%) | 1-201 (0.5%) |
There are huge differences between the numbers in the two tables (corresponding to home and road comeback probabilities, respectively)! For example, let’s look at the case of a 2-point lead through one quarter (top-left cell in each table). A home team in such a deficit still has a 51.7% chance of winning, whereas a road team with the exact same 2-point deficit only has a 39.2% chance of beating their opponents.
Are you thinking of betting your house on a home team leading by 20 points after quarter #3? Think again. While it may look like an impossible feat to accomplish, the numbers in the above table show that one road team did overcome a 20-point deficit after three quarters, while 201 teams failed. The only team to do it over the past 14 seasons is the Seattle SuperSonics on April 7th, 2007. And they did not even need overtime to do it! Trailing 87-67 after three quarters in Utah, they staged a furious comeback by outscoring the Jazz 39-16 in the 4th quarter, thus winning by a 106-103 score. I’m sure the 19,911 stunned fans at EnergySolutions Arena still remember that game.
Now, we can dig even deeper in order to come up with more accurate numbers. Recall our very first example: a home team down by 6 points through quarter #1. We saw earlier that such a team has roughly a 41.5% chance of making a comeback to actually win the game. However, things are very different whether we speak about a team that was a huge favorite coming into the game, versus a team that was already established as an underdog by bookmakers prior to the match. In other words, the pregame spread (or “pregame line”) has a big impact, and needs to be taken into account.
Following that advice, we break things down into 4 categories:
- Big home favorite (if home team was favored by 7 points or more)
- Small home favorite (if home team was favored by 0.5 – 6.5 points)
- Small home underdog (if road team was favored by 0.5 – 6.5 points, or pick’em game)
- Big home underdog (if road team was favored by 7 points or more)
As suspected, the comeback probabilities vary a lot from one category to the other. In our 6-point home deficit example, the big home favorite still has a 72% chance of winning (wow!!!), the small home favorite 41%, the small home underdog 29% and the big home underdog 10%.
Do you remember that huge SuperSonics comeback we told you about earlier? What’s even more astonishing is they were actually big underdogs, as the Jazz were 9-point favorites prior to the game. So next time you consider turning off the TV, leaving the arena or betting your house/wife/kids, just remember that tiny probabilities may still come back to haunt you!
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Thanks a lot for reading this 6-article series, we appreciate your time!
