Any gambler can beat the bookie


Note: Not at the old Poker1 site. Originally published (1999) in the Gambler magazine. This an early and expanded examination of the concept that you can beat sports books if you bet an odd number of games, 19 or fewer. There are other entries at Poker1 covering this topic.


Even if you know nothing about which football teams to wager, you can have a fifty-fifty chance of beating almost any sports book. Yes, I even mean the giant sports books in Las Vegas.

What? I see you getting ready to argue. Don’t. You’re thinking that most sports books (even illegal bookies) require you to risk $110 for every $100 you can win on a game. That 11-to-10 edge, you believe, is very hard to overcome. And you’re right.

Understanding the edge

Exactly what is that edge? Depends. If you’re looking at it from a bookie’s point of view, he can win one $100 bet and lose one $100 bet and earn $10 from the bet you lost (because you had to lay $110 to win the $100 that the bookie risked). So, the bookie earned $10 on a total $200 investment — and that’s precisely 5 percent. But, wait. How much is the bookie’s edge from your point of view? You risked $220 and lost $10 while splitting those two bets. That’s only 4.5 percent. (If you want even more precision, the 45 sequence goes on forever, so it would be 4.5454545 percent if you carried it out that far). The edge is usually cited from the bettor’s point of view, so that 4.5 figure (or “4.55 percent” commonly rounded off and quoted) is the one we usually use.

It takes some considerable handicapping skills to overcome that edge. So, why am I telling you that you can enjoy a fifty-fifty chance of beating a sports book or a bookie at football, even if you know nothing whatsoever about picking the right teams? It makes no sense to you, right?

Odd points, odd games

Well, it makes sense to me. The trick is to bet an odd number of games — up to 19 of them — with all the lines falling on half points so that there can be no ties. If you’re not a sports bettor, you might wonder what I’m talking about. I’ll explain.

Usually in football betting, the teams are not equally matched. To make the bets on each team fair, the sports book gives points to the weaker team. Let’s say Team A is 7½ points favored over team B. Then if team A wins 26-20 and you bet team B, you win. That’s because you get to add 7½ points, so the “betting” score is 27½ to 20 in your favor. You could subtract points from the favorite team, instead, and — in fact — that’s how most lines are quoted: “Buffalo minus 10,” meaning Buffalo is favored to win by 10 points.

Where was I? Oh… Like I said, you need to make sure that all the games you bet have half-point lines like 7½, 13½, 3½. Don’t bet any even-point lines like 4, 14, or 20. If you bet even-point lines, that will mess up our experiment and make me mad.

So, why are you just as likely to make money as the bookie by betting 1, 3, 5, 7, 9, 11, 13, 15, 17, or 19 games? Answer: Because you’re just as likely to win more than half the games.

Breaking it down

Let’s say you bet 11 games at $100. You win six. Fine. That’s $100 x 6 games won and $110 x 5 games lost. Since $600 – $550 leaves you with a $50 profit, you beat the bookie. And you are likely to beat the bookie and make at least this much just as often as the bookie beats you. This concept works all the way up to 19 games. If you win the minimum required to beat the bookie, 10, you won $1,000 on 10 games and lost $990 on nine games. That’s a meager $10 profit, but you still beat the bookie and you had a fifty-fifty chance of doing it. Just like I promised.

What I’ve just explained to you is one of the reasons why occasional bettors often think they can overcome the odds against them at a sports book. They are about as likely to win as to lose in the short term.

But what’s the catch. The catch is that — unless you have a solid, scientific basis for your handicapping — a sports book will extract its theoretical edge against you no matter how many games you bet. If you won 10 out of those 19 games, you made a $10 profit. But, if you lost 10 out of those same 19 games, you would have paid out $110 x 10 or $1,100 and won back just $100 x 9 or $900. Your net loss would be $210 winning nine games and your net profit would be $10 winning 10 games. And each of those outcomes is equally likely.

That’s why I advise that, unless you have significant skills as a sports handicapper, stick to poker where the better players often win consistently. — MC

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Mike Caro

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Known as the “Mad Genius of Poker,” Mike Caro is generally regarded as today's foremost authority on poker strategy, psychology, and statistics. He is the founder of Mike Caro University of Poker, Gaming, and Life Strategy (MCU). See full bio → HERE.

10 thoughts on “Any gambler can beat the bookie”

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  1. Tough crowd out there Mr. Caro, but you’re advice on beating the bookie is very sound. Ran it through a spreadsheet myself. I’ve never bet on a game other than hold ’em :-) but will keep this in mind just in case.

    Thank you,
    -William White

    1. But, remember, you’re not going to win MONEY doing this. You’ll still be at the same disadvantage, unless you have handicapping skills that overcome it. If you can make a large side bet with someone who will lay you, say, 6-to-5 that you can’t beat the bookie in 19 games by flipping coins to choose sides, THEN you have the best of it. Of course, even then, you’d need small bookie bets. Otherwise, this is just a mathematical curiosity.

  2. This would hold true if you only bet 19 games in your life, but with anyone reading this article, i doubt that’s the case. And i really doubt that 100 dollar player is going to get all that jazzed about going 10-9 for a dollar profit after investing 2200… thats a .45% profit (in case you didnt have your trusty calculator next to you.) Whoo hoo. Not exactly grocery money. So i think you can throw that one out the window.

    this is without a doubt the single worst sports betting advice column ive ever read. Stick to ridiculous videos with over the top examples on obvious poker tells, Mike.

    1. @gv2fly. I’ll assume you forgot to read my article and didn’t mean to make a fool of yourself in public. You say, “This is without a doubt the worst sports betting advice column ive ever read,” even though no sports betting advice is contained in it. The accuracy of the information and the concepts that it actually does contain are mathematically valid. You seem to suggest that it shouldn’t be used as a practical betting method, because you’d either win very little or lose very much — and that’s precisely the point I made.

      As far as the “ridiculous videos with over the top examples on obvious poker tells,” many are, indeed, exaggerated to illustrate the action, as I’ve clearly stated many times. Most were unknown to the poker community before I defined them 30 years ago, hoping to help poker players. If they seem obvious now, I’ve done my job.

      Your angry, hostile, hurtful, words have been noted. You have succeeded in ruining my life. Please carry on. — Mike Caro

      1. I will never get those five minutes of my life back. This guy does not have the ability to think logically when give multiple concepts. I felt like I was reading a creationists’ view of a six thousand year old universe.

        1. Go to Hell. Oh, wait, I’m not religious, so I take that back. So, since I’m therefore not a creationist, I’m left to ask you, what about the concepts I presented seemed illogical? If you explain what you mean, I’ll explain where your thinking is flawed. And that might help you going forward. (Or, maybe, your words were meant for another commenter above and simply placed in the wrong location. In that case, nevermind.) — Mike Caro

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