You’ve heard it a thousand times since you were a child. From your parents to your teachers to your forgetful friends: everybody makes mistakes.

It is a universal truth – and generally mistakes should be forgiven. Spilling your milk or forgetting to lock the door typically happen without serious repercussions. When the consequences are more significant, we face tougher questions: who did that mistake affect and should someone be held accountable?

This question has surfaced over and over in my 30 years of betting on sports. If the sportsbook makes a mistake and hangs a wrong number, or even a wrong start time, what is the ethical way to respond?

Do I max bet this huge advantage? Do I notify the book of their mistake and essentially do their job for them? Do I take a small nibble and hope it doesn’t get noticed? Imagine standing there with your bankroll ready, with the angel on one shoulder telling you to “do the right thing” and the devil on your other shoulder saying “they made the mistake, take advantage of it”. I have been faced with this moral dilemma many times at online and bricks-and-mortar books alike. Last week alone, I saw three separate instances of these mistakes.

Betting Mistake #1

The first was a blatantly wrong line on an NBA player prop. It was Game 1 of the Rockets/Thunder playoff series and DraftKings had James Harden Over/Under Rebounds set at 53.5. Yes, that’s 53.5 rebounds in one game.

I made the over odds at 2.6 billion to 1, considering that such a feat has only been accomplished once – by Wilt “The Stilt” Chamberlain, who racked up 55 rebounds in 1960. I figured as long as the game didn’t go 15 overtimes, the under was a great value bet.

Obviously, it was a simple typo. So that said, would it be unethical to make the under bet? At what point does it become our responsibility as bettors to NOT bet something like this?

Personally, as a professional bettor, I have never crossed that line.

I learned long ago that I want to maintain the best relationship with all my sportsbooks so they will continue to take my action. But what about the average Joe Bettor? Should they take their shot and hope to get paid, or is it cheating?

Betting Mistake #2

The second instance had bigger implications and was far less obvious. It involved Game 2 of the Raptors/Nets series. At halftime, the underdog Nets were up 3 on the double digit favorite Raptors. The second half line should have been Raptors minus 8 or 9, as the Raptors closed as a 11.5 point favorite before tip-off. The offshore book BetCRIS (Costa Rica International Sports), was the first book to issue a number. They also are one of the last true originators. Most sportsbooks copy the BetCRIS number within seconds. Here, BetCRIS made a clear mistake and set the Raptors 2H line at minus 3.5. Seconds later, 95% of books copied this number, including almost EVERY single book in Las Vegas.

So now, a game that should be lined at 2H minus 8.5 is available everywhere at minus 3.5. While I was almost certain it was an error, I still asked myself, “Was there an injury or ejection of a key Raptor player that I missed? If not, do I make the bet, knowing it is likely to be canceled once they catch the error?” Is it the book’s responsibility to know the line is incorrect and shouldn’t they have someone qualified to catch this huge mistake? Do I take advantage of their negligence or is it ethically wrong because I know the other books copied off a mistake?

In the end, the regulated books within the US that copied the line had to honor the mistake. However, if you bet minus 3.5 at BetCRIS offshore, I’m told, your bet was cancelled. So, the book that made the mistake had no accountability and the Vegas sportsbooks that copied that line had to make those tickets good.

Betting Mistake #3

The third example was last Monday night. Overnight baseball lines start posting around 6pm Vegas Time. There was a double-header between the Astros and Angels. The MLB rule changes this season dictate that double-header games go seven innings instead of nine. The originating bookmaker mistakenly posted a line based on nine innings and, of course, every other sportsbook once again copied that line. The over/under total on the game was listed at 10 runs. This line stayed posted for over an hour before some books quickly adjusted to 8.5 before trimming further the next morning to close at 7.5.

Anyone playing enough table games in their life has probably been overpaid before by mistake. Typically, it is a few dollars out of the umpteen millions casinos rake in every year. That said, I will not take an overpayment from a cashier or teller, where they are responsible for their own cash drawer. However, if a blackjack dealer is going to pay you on a 17 when they have an 18, I can see taking that for a few reasons.

Over the long run, the rare over and under payments tend to even themselves out. Also, the dealer individually is not going to be held accountable for the chip count being short due to multiple people winning and losing. Finally, the rules of the game are constantly altered so much in the casinos favor that I can understand taking advantage of a payment error as part of trying to bring the overall house edge down. Some of these casinos now only allow you to double when you have 10 or 11, will hit soft 17, and/or only pay 6:5 on blackjack. It’s not enough that roulette has a 5.26% house edge, now some Strip casinos have added a third triple zero on roulette tables which brings the game to almost an 8% house edge.

Karma plays a role here too. Even though it’s my occupation to beat the sportsbooks, I still have a moral compass. I won’t bite on a line error, take an overpay from a cashier, or bet a past post. That is where I come out. But the original questions remain for other bettors and for the market regulators alike. At what point does putting out a wrong line become the book’s responsibility and ethically allow me to feel okay to act? Should I care about mistakes made by these billion-dollar entities that are out to take my money? The answer is anything but black and white.