Props

Props create a massive attack surface for a sportsbook. Instead of keeping just two or three markets on a game that they can easily peg to a market maker, they’re keeping two dozen (or more) markets on the game, and they can’t easily peg these lines to a broader market.

Props are great because the openers are often (mis)priced based on a market line and total when the prop is made—and then they’re never updated. If there’s an injury or a change in weather or some other relevant information that hits about a game, the main markets will move, but often the props will just stay put.

Props also create opportunities for sportsbooks to make major mistakes. They can copy the pricing on a prop from another sportsbook, for instance, but accidentally word it differently. Something like

“Will Aaron Rodgers throw two or more touchdowns?”

versus

“Will Aaron Rodgers throw more than two touchdowns?”

Obviously, these are two very different bets, but a sloppy sportsbook could copy a price but transpose the words and give bettors a major opportunity.

Furthermore, with player props, information and breaking news that barely registers in the main market prices can drastically affect the value of a prop—and likely no one at the sportsbook will notice until they start getting bet.

For example, say two high-strikeout power hitters who were expected to be in the lineup at 11am end up on the bench and replaced with two high-contact, low-strikeout hitters. And you can still bet under on the opposing starting pitcher’s strikeout prop at the same price from the morning.

Or a cornerback who was expected to shadow a specific receiver is suddenly announced out with an injury from Thursday practice. And you can still bet that receiver’s yard and reception totals at the early week price.

Given enough props on the menu, darn near every news item can have a material effect on at least one of them. That’s just way too much for any sportsbook to keep up with. If you can stay on top of the news and learn to apply logic to the related bets, you can easily find edges.

Having said all that, while player props have been very beatable up until now, I expect them to get a lot of attention in the coming years. Already there are fantasy sports analysts who have pivoted to analyzing player prop bets. It’s likely that the number of people betting these seriously will explode. Explosion means more availability and higher limits—but it also means more market efficiency. Market maker books will likely start making more markets for these. More betting volume means books will pay more attention to these markets at competitors, and the price discovery plus copying process will take hold.

So go to town on them now, but be quick to recognize if those player prop markets start to get stronger over time.

Game props are team- or game-level bets. Will there be a defensive touchdown in the game? Which team will be first to score 30 points? Will there be a goal in the first 10 minutes of the game?

These props, like player props, are likely to proliferate in coming years. But I don’t think they will generate quite the increased attention from bettors that player props will, and as such, there’s a good chance they remain juicy targets for a while.

The great thing about these bets is that you can often deduce logically when these bets are good.

Typically, the pricing of game props is (or at least should be) directly related to the main spread and total of the game. Some props vary more with the spread and total than others.

A common game prop that doesn’t vary much is this NFL prop

“Will the final score of the game be odd or even?”

At first thought, you might assume this bet should be roughly 50-50. But it’s not—it’s slightly skewed toward odd being the favorite. The main reason is that a tie is an even score, and ties are uncommon.

“Ah. If the lack of tie games represents the biggest reason odd is a favorite over even, then odd should be a bigger favorite in games with low spreads and a smaller favorite in games with large spreads.”

This is correct, and it’s a perfect example of the type of logic you can use to beat these sorts of props.

Unfortunately, in this case, this effect doesn’t move the needle much. Games just don’t end tied in regulation that often—and of

those, a good portion end with one team scoring a touchdown for 6 points and an even final score.

This proposition varies from about 54% games ending odd at a PK spread to about 52% games ending odd if the home team is a 17-point favorite. This 2% swing is less than the hold on the bet. I can count on one hand the number of times I’ve found a good pregame odd/even NFL bet.

One popular NFL game prop that does vary enough to create good bets is

“Will one team score three consecutive times at any point in the game?”

If you aren’t familiar with this prop, it’s a widely cited example of a bet that’s counterintuitive to casual bettors. It sounds like scoring three times in a row is hard—but the reality is that when you have all game long to do it once, it ends up being a good favorite to happen.

But exactly how much a favorite depends on both the point spread and the total of the game. Logic suggests that this prop is more likely to win when one team will have trouble scoring. And that’s exactly the effect—in games where one team is a big favorite, this happens more often. And of those games with a nice-sized favorite, it happens more often when the game has a lower total.

Basically, when one team has a particularly low expected team total is when the fair value on this prop really starts to move.

The chart below shows what I make the break-even percentages on this prop using my NFL model. The columns represent different possible point spreads—it doesn’t matter whether the home or road team is the favorite. The rows represent possible totals.

0 3 7 10 14 17 37 62% 62% 65% 68% 73% * 41 62% 62% 65% 68% 73% 76% 45 62% 62% 65% 68% 73% 76% 49 62% 62% 65% 68% 72% 75% 53 62% 62% 65% 68% 72% 75% 57 62% 62% 65% 67% 71% 73% 61 61% 62% 65% 67% 70% 72%

You can see that the fair value on this prop can range from as little as 61% when the teams are evenly matched to about 76% when you’ve got an excellent team likely to beat up on a team with a hopeless offense. Because the fair value of the yes can move potentially up to about 15%, but the hold on this prop is usually only 4 or 5%, it’s very possible to find good bets. I’ve personally bet this prop many times.

Other NFL game and team props with fair values that vary enough with the spread and total to find good bets are

“Total field goals” “Total touchdowns” “Will the team that scores first win the game?” “Will the game ever be tied after 0-0?” “Will the first score be a TD or FG/SAF?” “Will there be a score in the last two minutes of the first half?”

And so on. Each of these props has a fair price that varies considerably with the pregame point spread and total. And for the most part, sportsbooks don’t do a great job of capturing this relationship when they open these prop markets.

Props are a great way to get started finding winning sports bets. They’re often weakly priced and not tied to a larger market. If you want a process for attacking these bets, try this one.

1. Find a prop where it seems the fair value price should change considerably in games with different spreads and totals. 2. Watch the prop for different games as it’s priced over time and try to reverse engineer the pricing. 3. If the prop is offered at multiple books, compare this pricing at several different places. 4. Watch it to see if others are betting the prop and determine how the book moves the pricing when you bet the prop. 5. Once you understand what is in the price and what isn’t, bet the prop whenever the price doesn’t seem to account correctly for the spread and total.