Do you know what’s magic about making fewer than 21 football bets against a bookie or sports book? If you do it right, you’re just as likely to win as you are to lose, even if you don’t have a clue which team to bet!

Let me explain. In sports betting on basketball or football you typically must lay $110 for each $100 you want to win. Fine. This means you’re going to have to win 11 out of 21 bets, on average, just to break even (because 11 times you will have won $100 for a total of $1,100 and 10 times you will have lost $110 for the same total of $1,100).

**Half points**

Now let’s eliminate the possibility of ties by assuming you *only *bet point spreads that are quoted in half points, such as 3½ or 7½ . With these “half point” lines, somebody must win, either you or the book. There can’t be a tie. Now, let’s assume you’re going to make an odd number of bets, so that your win and loss record cannot break even. When you make an uneven amount of wagers at half-point lines, either you or the book must win the majority. Nothing else is possible. It’s fifty-fifty who wins, assuming you’re just guessing.

So, it turns out that if you make any odd number of bets fewer than 21 using half-point lines, you are just as likely to beat the bookie as the bookie is to beat you. There is no such thing as being an “underdog to win” by making 19 bets or 15 bets or three bets. If you have no information and are just flipping coins to pick winners, you have as good a chance of winning the majority of your bets as of losing the majority of your bets.

**The problem**

The problem is that if you lose 10 out of 19, betting $110 to win $100 each game, you’ve lost $200, but if you win 10 out of 19, you’ve only won $10. So, the bookie likes your bets and is earning a theoretical profit, but he doesn’t have the better chance of actually beating you until you make more than 21 bets. **— MC**

why 19 bets max i dont understand can anyone help thanks

Hi, mr w — It’s because 21 is a break-even proposition, since that’s when the bookie’s money advantage (at 11-10 odds) exactly levels your fifty percent chance of “winning.” (“Winning” means making a profit, but you’re still getting the worst of it with 19 or fewer uninformed bets, because you’ll win less on your 50 percent successes than the bookie will on his.) Any even number of bets on half-point games doesn’t give you an equal chance of winning, either. That’s because if you split 10 to 10 (as an example), you pay the “juice” on your losses. — Mike Caro

Thanks Mike. This is the one I asked about on facebook. I bet at Bdog because thier lines are usually 1/2 point or more for the favorite. I like to bet the underdogs.

I usually make my own line before the offical line comes out and compare the two. I’m usually very close. I usually bet the teams that has a more than three point defference between the offical line and my line. I have been doing ok that way. I will do it again this year (On Pros only) and post my bets in chat here and see how I do.

Please note that this method (and the example) is presented for mathematical purposes.

Even if you know nothing about football, you actually do have a fifty-fifty chance of winning if you bet an odd number of 19 or fewer games. But — as explained in the entry — your money chances aren’t improved. This “system” would cost you much more on the times you lose more than half your games than your profit when won more than half of them.

Straight Flushes,

Mike Caro

Yes I understand that. I do ok betting pro football. The 1/2 point thing is something that I never though of. I’ll still pick the teams that I think will beat the line and if those teams are 1/2 point lines, the better.

I don’t bet much. Usually $5 or $10 bucks (straight bets only) a game to make watching it more enteresting. I’m not going to lose my shirt. lol