NBA Betting: Correlation Between Stats and ATS Records
by Trevor Whenham - 01/11/2008
When we are handicapping the NBA we spend a lot of time looking at, and talking about, offensive and defensive statistics, and we spend all of our time obsessing about how teams perform against the spread. Now that we are over a third of the way into the NBA season, I figured that it would be interesting and perhaps valuable to see how one thing is relating to the other. With that in mind, then, here's a look at how teams that are performing well in different statistical categories are doing ATS. It's just a hunch until I do the work, but I guess that some statistical categories will correlate very strongly, while others will hardly relate to betting success at all. Let's see if I'm right:
Points scored - Only one category in and already a bit of a surprise. Of the top five teams in points scored so far this year (Phoenix, Golden State, Lakers, Denver, Utah) only one, the Lakers, are profitable against the spread. I might have assumed that a team that scores a lot would be able to cover a lot of spreads, but I suppose that that effect would be offset by a couple of things - those teams aren't all known for the defense, and the explosive offense attracts the public attention and probably negatively affects the lines of those teams. For what it's worth, scoring few points is worse than scoring a lot - the bottom five teams in scoring are all unprofitable.
Field goal percentage - Shooting efficiently is marginally better than scoring a lot of points when it comes to betting success. Two of the top five teams have been profitable on the season, and the sixth, seventh and eighth teams in the category have been wildly profitable as well. Most compellingly, the top five teams against the spread are all in the top eight in field goal percentage. Three point shooting is almost as good as an indicator, though one of the top five ATS teams, Orlando, is only 13th is three point percentage.
Rebounding margin - Someone told me when I first got interested in sports betting that a team that consistently out rebounded their opponents was a very good bet over the long run. I will now have to consciously forget everything he told me. There are six teams in the NBA that have a rebound margin of +2.0 or better. Of those six, only one is profitable ATS. Rebounding is good for momentum, and it is often fun to watch, but it does little for profitability.
Points allowed - There are only 10 teams that are profitable against the spread. Six of them are in the top eight for fewest points allowed. Those top eight teams are a combined 156-112 ATS. You could do worse than blindly bet on the stifling defensive teams. By contrast, none of the bottom eight teams in defensive effectiveness are profitable ATS, and they have a truly dismal combined ATS of 126-151.
Field goal percentage - At first glance, being able to limit the opponent's ability to shoot is a quick route to betting profitability - the top three teams in the category are all among the five most profitable teams in the league. A closer look, though, dilutes the enthusiasm significantly. The gap between the third place team and the one in eighth is very small (43.7 percent versus 44.4), so you can hardly differentiate between the top three and the top eight. While the top three are all profitable, three of the next five teams are not. The other problem with reading any significance into this category is that the difference between the second best team in the category and the 19th is less than two percentage points. A team could move up or down in the rankings with only a small change in their performance so the rankings have little real meaning, and making betting decisions based on the rankings would be dangerously ill advised.
Blocks and steals - I grouped these two categories together, because they have a few things in common - they are both glory categories that are fun to watch and often make the highlight reels, and neither category contributes much to the betting bottom line. Only one of the top five teams blocking teams, and just two of the top five teams for steals, have made their backers any money over the course of the season. As further proof of how little these categories should concern bettors, two of the bottom five teams in the league in steals are among the three most profitable teams in the league, and two of the bottom five for blocks are profitable as well.