Second Half NBA Comebacks and Failures

How many times have you heard somebody say “just watch the final five minutes of the game” when describing the NBA? The reasoning behind this statement is basically anything can happen for the first 43 minutes and it really doesn’t matter. Leads come and go, sometimes even quite large leads.

Since the 2003 season, do you know what the largest lead a team had in a game that they ended up losing straight up? (hint: it happened this season) I’ll give the answer at the end of the article. Maybe watching the final five minutes of a game is fine for a fan, but sports bettors need to know more about the dynamics of a game to assist them in handicapping.

I like to look at basic occurrences in a previous game or games and see how a team reacts in their next game. A dynamic that happens frequently in the NBA is when a team comes from being behind by a big margin to win the game outright. I wanted to see if there were any angles worth noting in a team’s next game after such a comeback victory. It would seem like a good spot for a letdown since the team has to be feeling pretty good about themselves to snatch victory from the hands of defeat. Plus, a letdown could occur as a team might have expended quite a lot of energy in their comeback. Starters might have played longer than normal so physical fatigue could be an issue. So could mental fatigue as comebacks require tremendous focus and intensity.

The time frame I used for my research was the beginning of the 2003 season onward and did not include any playoff games. I started with a basic situation of a team in their previous game being down by ten or more points at halftime but who came back in the second half to win the game. Teams that had this type of win in their previous game only covered the spread 41.8% of the time, 110-153, in their next game. This is an exceptionally easy angle to look for that has produced 58.1% winners betting against comeback winners since 2003. The Under had a slight edge at 52.1%.

I could end this article here and be pretty happy with providing that 58.1% stat all by itself. (it would also save me hours of work!) But, as always, it is good to try to find additional examples of winning angles to make money with.

I wanted to use halftime scores as they are more etched into players' minds than just taking the biggest point deficit during a game. There is discussion at halftime between coaches and players about first half-performance and how to play the second half with new strategies and ways to attack and defend the other team.

I did research on what happens in a team’s next game after they overcame a ten-point deficit at anytime during the game, not just halftime, and went on to win straight up. Whereas our halftime deficit of 10+ results in a 41.8% ATS rate in the following game, if the deficit occurred at anytime during the game there is a 48.0% ATS rate in the team’s next game. So a halftime margin is more important than a random one. Let’s add some qualifiers to our base trend, down by 10+ at half and winning the game. First, if our team is playing their next game without any rest, there was not much of an improvement betting against them but it did give us a totals situation worth considering with the Under happening in 56.2% of those games.

If our comeback team is favored in their next game they only cover the number at a 39.7% rate as compared to the dogs at 44.8%. Away favorites are 36.8% ATS and home favorites clock in at 40.8%. You don’t want to bet against home dogs, 51.4% winning ATS, but away dogs are only 42.1%. Another nice trend to note is the Under cashes tickets at a 65.8% clip for away favorites.

Would the competition in the next game make a difference in our results? Not in the case of whether the next opponent is a conference or non-conference foe as the ATS records are almost exactly the same in coverage rate. If the previous game where our team rallied to win was against a non-conference foe and now we are playing a divisional rival, the game goes Over the lined total 63.0% of the time. If the opponent in the previous game was a divisional one and this one is a non-conference game, playing against our team improves to a 65.2% mark. Beating a divisional rival after being down to them at halftime obviously carries more of a hangover for our team if they are playing a non-conference squad in their next contest.

I next looked at the location of the games. We did have an improvement of betting against our team from the base rate of 58.1% when no exact site was specified to 63.5% if both the previous game and the current game are on the road. The Under has a 58.8% success rate, also. An interesting twist on looking at the sites of the games is when both games are being played at home with the added condition of our team’s next game being on the road. When that happens, playing against our team in the second game is a 65.9% winner with now the Over being the total to bet on, a 56.8% occurrence.

We have talked about teams that rally from a halftime shortage of ten or more points to win a game. How about the team that blew that lead and lost, how do they do in their next game?

Since the start of the 2003 season, teams off of a blown lead and loss are covering the point spread in 54.7% of their next games. Teams that are playing on the road after their previous game was also on the road win 58.1% of those second games against the point spread. The best advantage came in betting the Under in these games, a 62.7% winning situation.

In this post-blown lead and loss circumstance, dogs and pick’ems were the side to bet on winning 57.0% of the time versus just 51.4% for favorites. In looking at conference and division combinations, there were a couple of situations that improved our base trend significantly. If the second game was against a divisional rival, our team covers the spread 61.5% of the time along with a 60% Under bias. If the previous game where our squad let the lead and game slip away was against a divisional foe and we are now an underdog in our next game, our ATS success rate improves to 64% and our Under bias raises to 72%. Our Under rate improves further to 77.3% if we are now playing a conference foe in the second game.

I increased the halftime deficit to 15 or more points for our team that rallied to win to see if there would be a betting advantage we could use. The only thing that really stuck out was the Over in our base trend occurred 56.9% compared to a 47.9% frequency when the deficit at half was only 10 points or more. Teams must be less focused and play with a little less intensity on the defensive side when they have even a bigger come from behind win.

I asked the question earlier in the article what was the biggest lead a team blew in a game that they lost straight up over the past five years. The answer is 29 points, which Minnesota blew on 12/30/08 on the road at Dallas. The Timberwolves were up by 22 at half and increased their lead to 70-41 early in the third before the Mavs reeled off a 22-2 run to get back in the match.
It’s time to start paying attention to halftime scores so you can take advantage of the profitable situations that happen when a team rallies to win in their previous game and also those games after a team blows their halftime lead and loses.

Jim Kruger of Vegas Sports Authority penned this piece.