Zoltar is my NFL football prediction computer program. It uses custom reinforcement learning and a neural network. Here are Zoltar’s predictions for week #19 (wild card round) of the 2021 season. It usually takes Zoltar about four weeks to hit his stride and takes humans about eight weeks to get up to speed, so weeks six through nine are usually Zoltar’s sweet spot. After week nine, injuries start having a big effect.

Zoltar:     bengals  by    1  dog =     raiders    Vegas:     bengals  by  6.5
Zoltar:       bills  by    6  dog =    patriots    Vegas:       bills  by  4.5
Zoltar:  buccaneers  by    6  dog =      eagles    Vegas:  buccaneers  by   10
Zoltar:     cowboys  by    6  dog = fortyniners    Vegas:     cowboys  by    3
Zoltar:      chiefs  by    6  dog =    steelers    Vegas:      chiefs  by 13.5
Zoltar:        rams  by    6  dog =   cardinals    Vegas:        rams  by  4.5

Zoltar theoretically suggests betting when the Vegas line is “significantly” different from Zoltar’s prediction. In mid-season I usually use 3.0 points difference but for the first few weeks and last few weeks of the season I go a bit more conservative and use 4.0 points difference as the advice threshold criterion. In middle weeks I sometimes go ultra-aggressive and use a 1.0-point threshold.

Note: Because of Zoltar’s initialization (all teams regress to an average power rating) and other algorithms, Zoltar is much too strongly biased towards Vegas underdogs. I need to fix this.

For week #19 (wild card):

1. Zoltar likes Vegas underdog Raiders against the Bengals
2. Zoltar likes Vegas underdog Steelers against the Chiefs

For example, a bet on the underdog Raiders against the Bengals will pay off if the Raiders win by any score, or if the favored Bengals win but by less than the point spread of 6.5 points (in other words, by 6 points or less).

Theoretically, if you must bet $110 to win $100 (typical in Vegas) then you’ll make money if you predict at 53% accuracy or better. But realistically, you need to predict at 60% accuracy or better.

In week #18, against the Vegas point spread, Zoltar went 3-1 (using the standard conservative 4.0 points as the advice threshold). Overall, for the season, Zoltar is 65-51 against the spread (~56%).

Just for fun, I track how well Zoltar does when just trying to predict just which team will win a game. This isn’t useful except for parlay betting. In week #18, just predicting the winning team, Zoltar went 9-7 which is very poor.

In week #18, just predicting the winning team, Vegas — “the wisdom of the crowd” also went 9-7, the same as Zoltar.

Zoltar sometimes predicts a 0-point margin of victory, which means the two teams are evenly matched. There are no such games in week #19. In those situations, to pick a winner (only so I can track raw number of correct predictions) in the first few weeks of the season, Zoltar picks the home team to win. After that, Zoltar uses his algorithms to pick a winner.

My prediction system is named after the Zoltar fortune teller machine you can find in arcades. My favorite arcade games are pinball machines. Here are two NFL football themed pinball machines. Center: “Pro Football” (1973) by Gottlieb. Right: “Monday Night Football” (1989) by Data East.