How to make your own moneylines in MLB

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A variety of ways exist to make a run at creating your own moneylines for handicapping Major League Baseball games. Quants have complicated calculations that determine the worth of every player in the lineup and build a projection out of that. However, some old-school sharps are so familiar with the teams and market tendencies that they trust their gut to make a number, then compare that to the board.

The first obvious hurdle to clear is accepting that this isn’t football or basketball, with everything expressed in points. In those sports, teams are scoring points on the field or on the court to determine who wins. Sportsbooks post a point differential, and bettors take shots at it. Everybody speaks the same language. Are the Cowboys three points better than the Giants? You make your bet. The teams will play a game that ends with a point differential.

 

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In baseball, the Yankees aren’t trying to drive dollars and cents across the plate to beat the Rays. What does it mean to lay a buck fifty that New York will beat Tampa Bay?

Luckily, there’s a relative shortcut. Even though runs and dollars don’t speak the same language, both communicate very well with win percentages:

 

— A -200 favorite has to win 67% of the time to break even.

— A -175 favorite has to win 64% of the time to break even.

— A -150 favorite has to win 60% of the time to break even.

— A -125 favorite has to win 56% of the time to break even.

 

(Here’s a chart we found via Google that shows you the win percentages for more prices.)

 

If you want to figure out the win percentage for any given line, simply divide the moneyline you’re seeing by that number plus 100. Easy once you get the hang of it. Grab a calculator. What’s the break-even win percentage for -132? Divide 132 by 232 and you get .569, or 57%. What’s the break-even win percentage for -164? Divide 164 by 264 and you get .621, or 62%. Just mentally add 100 to the number you’re seeing after you hit the divide sign. Wait, Kershaw is laying -360 against a minor-league call-up for the Padres. What’s the break-even for -360? Divide 360 by 460 and you get .782, which is 78%. Don’t lay those odds with Kershaw unless you’re confident the Dodgers win that game 80% of the time. 

OK, we know how to turn a moneyline into a win percentage. How do we turn runs into a win percentage? There are a variety of complicated ways to do this. A relatively simple method that will get you very close is to use the classic Pythagorean projection created by the inspiration for sports analytics, Bill James. That formula turns runs into a win percentage, which works great for our purposes.

The Pythagorean formula is runs squared, divided by the sum of runs squared plus opposition runs squared. Easier to visualize if I give you an example. 

Let’s say you project the favorite to win a game 5-4. However you get there with your mathematical assessments for each team, you’re arriving at a 5-4 victory for the favorite. Plug that into the formula, and you get 25 over the sum of 25 plus 16. That represents 5 squared divided by the sum of 5 squared and 4 squared. Ultimately, 25 divided by 41. 

Your projected 5-4 win now projects to a no-vigorish win percentage of .610, as 25 divided by 41 is .609756. From the little chart above, you know that means over -150 on the money line — about -156, to be more accurate.

Even though teams don’t score “dollars and cents,” you’ve now turned a 5-4 score projection into -156 on the money line because both runs and betting odds can be expressed as win percentages. 

Let’s do another one. The imaginary game is in Arlington, so you’re getting a higher final score. Your projection is 6-4 for the favorite. That’s 36 divided by the sum of 36 and 16, which is 36 divided by 52, which is .69230. That’s in the area of -225 on the moneyline. 

Obviously, having a spreadsheet is very helpful as a time-saver. And any serious effort at projecting scores isn’t going to land on many whole numbers. You’re going to get projections of 4.7 to 4.3, or 4.1 to 3.6, or maybe 6.5 to 5.5 if you’ve adjusted properly for the altitude in Colorado. Familiarity with a spreadsheet will help you make accurate run predictions and turn those into accurate projections of win percentages that you can compare with the moneyline. 

I know. I said “a relatively simple” method, and it sounds like the drudgery of homework seven days a week. Or like juggling bowling balls while riding a unicycle if you hate doing math. Well, cutting-edge baseball math is significantly more complicated, involving algorithms, models, tweaks for weather conditions and even a variety of exponents within updated versions of the Pythagorean formula. When you’re betting into the baseball market, you’re joining some esteemed company. But knowing how to create your own moneyline will help you make smart choices in that market. Most importantly, if you’re doing it right, it well help you cull mistakes you had been making in the past.