Gridiron Gold: Parlay Math Explained

Week 13 with Professor MJ - (AND A FREE MONTH OF PICKS ACCESS)

This article will likely be the biggest habit changing piece I have ever written.

I have long said that making the wrong choice in bet type can far outweigh the small edges obtained when placing good bets. This is primarily in reference to parlay betting. Today, while highlighting the work on Professor MJ, I will help break down parlay math and why these plays are generally bankroll murderers… and actually the fastest way to lose money.

In all aspects of sports betting, there is always a reason or example where it is correct to break the rules, so I will also explain the few times a parlay is actually a good idea.

Professor MJ is really a man named David Beaudoin. He is, or was, a statistics professor in Quebec who has done some work in the sports betting world. Because Beaudoin also practices Advantage gambling strategies, he refers to himself as a “Sports Investor” and not a gambler, knowing that extracting small edges will result in profit in the long run.

Before we start, I want to point out the following math assumes a bettor is choosing a standard -110 line and has a 50/50 shot at either side winning the bet. The math obviously changes with certain variables, like if you are putting juiced ML favorites which obviously have a higher chance of winning. This is the most common approaches to parlay betting, stack together long odds to reduce them. However there is a vast reduction in the parlay multiplier when doing so. In fact, parlaying juiced ML favorites is one of the single worst types of parlays imaginable. Stacking together heavy favorites thinking you are now getting decent odds is categorically FALSE!!! In reality, stacking juiced MLs together actually makes each individual leg even more expensive. It’s fucking brutal. Stop doing this immediately if you do.

I am going to share with you what I think is the most important graphic to understand how bad parlay betting is. I made this chart to easily highlight the atrocities in parlay math. It details first the amount of legs in a given parlay, and then the standard house multiplier for those wagers. The last two columns reflect the number of true outcome combinations in a given parlay, as well as the expected ROI on these bets. Look how staggering this is.

• The way to calculate the number of outcome combinations in a parlay is by using an exponential formula. OC = 2^N

• The Standard multiplier is what all sports books give for parlays that pair randomly selected -110 lines (slight caveats for SGPs and correlated lines - which just makes this EVEN WORSE for the bettor).

• The correct odds at 50% win should be: Correct Odds = Outcome Combinations - 1. Therefore, a 2 leg parlay should provide a 3:1 payout, and a 8 leg parlay should provide a 255:1. It’s an insane ripoff to accept 176:1, yet a bunch of schmucks think choosing 8 different NFL games correctly against the spread is worth the chance of turning $100 into over $17,000. Looks nice, its a pathetic joke. Fair odds payout is over 25 grand.

The reason this topic gets me so fired up is because sports gambling across various mediums has become a blitz of parlay gratification. Every Sunday we will see on Gambling Twitter a few aggregated Anytime Touchdown Parlays that are 100:1 and actually hit. Or someone correctly picked the MLs for all 16 NFL games and turned $100 into $20k. Look how easy that was! Next week, IT COULD BE YOU! 🤦‍♀️🤮😡

Because common folk see so many aggregated parlays, because the user interface of these betting websites have them promoted everywhere, because sports influencers with big platforms are giving out parlays of the day, people entering the betting space instantly gravitate towards dumb fucking betting.

I actually started my podcast, The Advantage Sports Betting Podcast, because I was an amateur winning sports bettor for 7+ years and noticed the legalization shift, the emerging content in the space, and I was actually horrified. My simple thought process was - there has to be a lane for responsible and smart gambling practices. That’s why I appreciate all of you guys for reading and taking my information seriously, so let’s keep diving deeper into parlays.

If the math didn’t sway you - consider what the states are reporting for their gambling earnings and market holds.

Another way to go about winning at sports betting is by doing things where the sports books generate the lowest edge. It is, in a sense, reverse engineering some of the data to learn how and where to best place your action. I often talk about a sports books “hold.” Hold is the percentage of a bet placed that they are likely to win on a given bet type. It is essentially the house cut or the rake rate.

In September of 2024, New Jersey’s sports betting data shows the books had an average hold of 24.2%, while everything else had a combined 4.4%. On the full year basis, the average hold of parlays is 19.7%. That means the book makes 4-5x as much per parlay bet as they do straight bets. The takeaway: STOP PLACING THE BETS THE BOOKS CLEAN UP ON!

Compounding The Issue- Hedging a Parlay

Hedging a bet is generally a -EV move. The decision to initiate a hedge has to be for good reason. A bet coming close to winning is not good reason. One example of this is would be placing a bet on NFL over when the number is 41. At halftime, you notice the bet is doing well and the live total is 54.5. This is no reason to play an under live, or move the alternate line to something above +money to hedge/arbitrage the original -110. Playing like Under 51.5 (+120) on a live line simply because your bet is doing well is dumb as fuck, and will cost you so much gained value in the long run.
In this (made up) scenario, hedging becomes possibly a worthwhile move if the winning team’s quarterback gets injured, and suddenly the replacement option is very lackluster. The team that first scored a majority of the points accounting towards your over may opt to run, try and burn clock and hold a lead. There has to be a reason to hedge beyond - oh this bet looks good and I can lock in profit. Locking it profit likely negates a lot more profit on the backend.

Ok so let’s take this one step further. The most idiotic thing you can do in parlay betting is hedge the last leg simply because all the other legs have hit. Parlays are already -EV, so hedging is compounding -EV tactics on top of one another. This will evaporate your bankroll. Say you place a 5 leg parlay and decide to hedge the final leg, or possibly even cash out. These are brutally costly moves. If you were going to hedge at the final leg simply because you got there, you should have just submitted a 4 leg parlay instead of 5. By hedging a parlay simply because its on its last leg, you are costing yourself more than simply placing 1 less leg in the parlay in the first place. Like mentioned before, if there is an actionable reason to do so, it’s a different scenario.

When Parlays can be beneficial:

I am genuinely terrified to write and send out this information. The reason is because people learn some advantageous angles to parlay betting and then go crazy looking for these opportunities. In turn, bettors with inadequate understanding of this place parlays that they think fit the bill for smart plays, yet they are not, and it actually becomes costly. Do not do that! Let them situationally find you. Despite knowing these tactics, it is incredibly rare that I place parlays. I have placed less than 5 this entire year.

That being said, if your hit rate is 55% on -110 bets instead of 50%, using parlays can be profitable and smart. Having a 55% hit rate and putting everything into a standard 2 leg parlay at +264, would net you an ROI of 6% instead of 3% putting all of those into straight bets. However, hitting 55% is difficult and should not be assumed to be accomplishable on a long term scale, even if you hit 55% over the last month or so.

Since this is an NFL betting guide, I will use a rare time it is ok to parlay in NFL terms but also explain why its so hard to gauge if it is actually worth it. If you are betting opening lines or early enough in the week where bigger line moves may hit the board, and two lines exist at the same book that are the best price on the market that you were going to bet anyways, and you feel like are both individual lines are going to obtain clear closing line value, then it might be wise to parlay them. The reason why this is so hard to do in the NFL season, especially this one in 24-25, is because the amount of bouncing lines throughout the week. What appears to be a sharp side early in the week may get hit back the other way and close right back at the original number you bet, and in that case holding a parlay ticket is scary. We have seen this more in this NFL season than any in the past.

Maybe you are tracking weather for a particular area and know a storm is coming but that information has not hit the market yet, betting into the total which could see a dramatic shift is smart - and could be worthwhile in parlays. Maybe you are tracking a team very closely that you are a fan of, and have an inside to understanding the injury report and who is actually going to be active/inactive, it could be worthwhile to bet a line if a key injury news is going to come down. Actually knowing with a high enough degree of certainty you are going to be right in those circumstances though, very tough, and thus generally worth avoiding.

Another key when finding this spots to place a parlay is that the games you are pairing together should never start at the same time, ideally they simply do not overlap when they are occurring live. By having games in different windows in a parlay, you remain incredibly flexible in your position as one leg ends and the next approaches. You can hedge (if you have actionable reason), you can possible open a middle. Maybe the side you originally parlays was an NFL team -2.5, but now you want to take the +2.5 side and put it in a wong teaser, and be able to middle it. Use island NFL games (Thursday, Sunday Night, Monday Night) as places to latch onto Sunday spots if the opportunity presents itself.

DISCLAIMER: Throughout this series I have gotten a ton of positive feedback and some messages explaining to me how the strategies I have laid out have been properly executed and led to a winning bet. I love getting these messages, but let me stop you on this one before you start. Do not reach out to me about your parlay that you got closing line value on every line. Do not reach out to me about hitting a 2 leg parlay that you felt you knew which way the line would move. I’m being honest to say that yes there are ways to make the math work, but I’ll be a bit blunt and honest that I do not care about your parlays. I hope they all hit, I hope we destroy the books and make money, but don’t message me about parlays, I likely wont bother responding. Message me about your straight bets only! Message me to say you appreciate such nuanced reasoning to show how detrimental parlays usually are (the button is above 😂).

The Whop Picks Packages allows all access to my picks in real time when I place them so you can get ahead of the market with me.

No fluff because it’s the last day this is available. Anyone who signs up for my picks package in the next 24 hours will get an addition 31 days of credit added to their account. If you sign up for 1 month, you essentially get two right now. It is $100 monthly, and this gets you picks access for the next 62 days, an average of less than $2 daily. You can cancel at anytime. I hope you join me and we can have an awesome December/January. Let’s go!

As of now, here is my card for Sunday December 1st. I have two massive middles set up on the Falcons/Chargers game and Josh Allen’s Rushing Yards. PRAY FOR ME THAT I HIT JUST ONE OF THOSE!

By the way, finding positive value middles are long shot bets where you are paying 5% implied probability and obtaining 20:1 odds. Screw -EV parlays where you stack 6 winners together, some are correlated in an SGP, some are heavy juice, and you get 14:1 odds. It’s a complete rip off. Ride with me on some positive value middles that can be absolute bankroll exploders when they roll.