OddsJam: Odds Comparison and Statistical Tools for US Bettors

28 April 2021

The casual NFL bettor typically bets purely for the thrill of winning, to enhance the fun in watching a game in which he/she might have no emotional stake. When that bettor seeks to level up into professional mode, however, he/she must learn about arbitrage bets (or arbs); OddsJam is a burgeoning online engine which will be boon for sports bettors in the US.

The science and art of arbitrage betting

Arbitrage betting has been employed by crafty bettors since the first time a competing bookmaker moved into another’s territory. Simply put, arbitrage betting is the science of covering both ends of a given bet yet still turning a profit thanks to divergent odds offered among sportsbooks.

Speaking (writing?) more precisely in terms of mathematics, a gambler can automatically turn a profit by covering both possible outcomes of a single sports event if the sum of the inverse of the outcomes is less than 1. Put simply, the proper “arber” is looking for discrepancies in the implied probability of outcomes.

To use an example, let’s say the Philadelphia Eagles are pretty strongly favored over the Atlanta Falcons. At Sportsbook A, the money line (ML) on the Eagles is -373 (or 1.27 in decimal odds notation). At Sportsbook B, the ML on the Falcons is +380 (or 4.80). The inverse of these outcomes are:

Eagles at Sportsbook A: 1.27^-1 = 0.7875
Falcons at Sportsbook B: 4.80^-1 = 0.2083

And, since 0.7875 + 0.2083 = 0.9958, the Eagles-Falcons game makes a winning arb bet.

Betting $100 on the Eagles nets the bettor $127 with a Philly win; putting down $26.46 (determined by dividing the shorter odds into the longer odds and multiplying by the first wager’s amount; in this example, 1.27/4.80 x $100) wins $127 on the Atlanta upset. A profit margin of 54₵ on a $100 investment may appear quite small – just barely over a half-percentage point – but over 80% of arb bets earn less than a 1.2% profit margin.

How OddsJam works

As in many areas of betting, the interwebs have proven a double-edged sword. On the plus side, instant access to breaking news can bring opportunities to wager before the odds change; and depending on geography, nearly every sports bettor living outside of Nevada has access to dozens of sportsbooks – and the opportunity to catch discrepancies in offerings – that just didn’t exist a decade or two ago.

Bur remind yourself that the sportsbooks enjoy just as much access as do you atop any inside knowledge they may boast. And with universal connectedness, the chance of finding advantageous offerings (or even serious variance) decreases greatly. Beyond these considerations is the current era of decriminalization proceeding state to state, each with its own licensing and approval of sportsbook websites.

Here’s where OddsJam comes in. OddsJam aggregates sportsbooks’ offerings on player over/under props, pointspread and money line bets – essentially any bets with two outcomes. And then they do the hard calculations for you, pointing the way to the most advantageous differences between sportsbooks.

At present, the site regularly runs lines when available in football, baseball, basketball, hockey, soccer, tennis and UFC. (NFLbets’d guess the next markets OJ would offer are golf and elections; the latter would require some adaptation of OddsJam’s current format, and the latter wouldn’t really need to be established before, say, fourth quarter 2023. Adding those two to the original six offerings would cover, at a guess, approximately 99.99% of all sportsbook wagering in North America.)

The basic calculations, i.e. the amount of variance between sportsbooks’ implied probability sets, are available to anyone checking out the website. Paid subscribers get access to the complete suite of odds comparison and statistical tools. More such tools will be added to OddsJam in the near future, but the most important statistic for arbers – the percentage variance – is already included and updated whenever new lines are reported.

As the site is designed primarily for US bettors, OddsJam aggregates odds and lines from all sportsbooks licensed for the player’s state. As of this writing, this includes Colorado, Illinois, Indiana, Iowa, Michigan, Nevada, New Jersey, Pennsylvania, Tennessee, Virginia and West Virginia. We expect this list to continue expanding.

In short, OddsJam provides incredibly valuable tools for the would-be arber – but even standard NFL bettors can benefit from such information. This is some powerful stuff.