Using Computer Ratings Systems in Sports Betting

Betting on sports has always been part art, part science. Successful sports betting takes a feel for the game you’re betting on, a lot of knowledge about injuries and trends, and an understanding of the odds. Combine all of those, and you might just come out on top.

But in the modern world of sports betting, we have even more tools at our disposal than ever, and not taking advantage of them means you’re not doing everything you can do to win. Nowadays, there are an unlimited number of computer simulations and formulas designed to rank and rate teams in just about every sport you can think of – and with a little thought, it’s easy to see how you can utilize them when making sports picks.

Many sites that offer sports betting strategies say that their picks were computer generated, without showing any of the work. Many of these sites are honest about where their picks are coming from; some are not. But for now, let’s talk about those systems in which we can actually see the team ratings. Many of these rankings aren’t even designed for people who bet on sports, but this can be a benefit, rather than a drawback; a pure system without biases related to gambling might give us truer rankings than one designed to “beat the system.”

Let’s see how we might use one of these computer systems to help us bet on sports. For this example, I’ll use Jeff Sagarin’s NBA ratings. Sagarin has a laundry list of well-respected ratings systems available on USA Today’s website, all of which include a metric called “PREDICTOR,” which attempts to determine exactly how many points better one team is than another. Tonight, the Chicago Bulls are favored by 4.5 points over the Boston Celtics – a game with a line that can illustrate both the strengths and weaknesses of computer ratings.

Looking at the Sagarin ratings, Boston has a PREDICTOR score of 93.76, against Chicago’s score of 88.07. This tells us that Boston would normally be favored by about 5.7 points against Chicago on a neutral court. Chicago is at home, meaning we have to give them the home court adjustment of 3.02 points, making Boston just over a 2.5 point favorite. With Chicago giving 4.5 points instead, this seems like an easy play: take Boston and the points, or even the money line!

Not so fast. Rankings like the Sagarin ratings are a good way of telling us how teams match up when all things are equal, but we can’t just look at one system if we want to win at sports betting. In fact, when the spread is so far off from a highly regarded computer rating, we shouldn’t get excited – we should get suspicious! Before you bet on any game, you need to ask yourself what other factors might be influencing the line. Does one team have more to play for than the other? Are there any injuries or suspensions that hurt either team’s chances? For outdoor sports, is the weather expected to be a factor? Does one team have favorable matchups against the other?

In the case of this game, there are definitely confounding factors we need to consider. I didn’t mention that this game was taking place at the tail end of the NBA season, and that Boston had nothing to play for – their playoff seeding was already locked in, meaning several of their star players might play limited minutes, or not play at all. Meanwhile, Chicago was fighting for a playoff spot and was certain to go all out for a win. Factors like these are rarely taken into account by computers – that’s your job as a good sports bettor.

Computer sports ratings are a great tool for a gambler looking to bet on sports, but that’s all they are – a tool. They should be part of your decision making process, but they can’t replace your judgment and knowledge of the sport itself. Use rating systems to set a baseline for teams, and then take other factors into account to adjust from there, and you’ll be well on your way to winning more sports bets.