Guide to Betting on Sports: What Are Props?

There is no way to comprehensively list all types of "prop" bets offered by sportsbooks, as really it functions as a miscellaneous category. Anything a sportsbook posts lines on other than what it considers standard bets on major sports can be considered a prop.

Which lines are deemed miscellaneous like that can differ from place to place. For example, many sportsbooks now offer lines on just the first four and a half or first five innings of baseball games. At some places you will find these listed under "Baseball" or "Baseball-1st Half," whereas at other places you'll need to look under "Props" or "Baseball Props."

But as one would expect, prop bets vary widely. All the following, for instance, would be considered props:

* Head-to-head match-ups between two golfers, for a round or a tournament.

* Picking the round a knockout will occur in a boxing match.

* Odds on the American Idol winner.

* Over-Under on the longest field goal kicked in a football game.

* Over-Under on the number of points scored by a player in a basketball game.

* Odds on whether a football team that's currently 10-0 will finish the season undefeated.

* Odds on the Heisman Trophy winner.

No doubt props can be "fun" to bet, but all that means is people are tempted to bet them when they shouldn't. Like any other bet type, you should only be betting props when you have an edge.

How do you identify situations where you can gain an edge on props? First off, I would eliminate all the garbage "coin flip" type props that are almost entirely a matter of chance and can't really be handicapped. For instance, there's not much point betting a football prop about whether there will be an odd or even number of punts in a game. Or which team will get the first first down in a game (since that's largely a function of who will have the first possession, which is largely a function of the coin toss at the beginning of the game). Or whether a game will have a missed extra point (since missed extra points are rare and are distributed nearly randomly when they do occur).

But certainly there are many props that can be researched. Sticking with football, for instance, there is a lot of available information you can put to use in betting player props. Think about how much work obsessive geeks put into fantasy football, and how much of that is distributed free or cheap. If you're looking to bet a prop on Adrian Peterson Over/Under 88.5 rushing yards, why not check the fantasy football sites that seem to put the most work into their projections? If the consensus is he's likely to have about 18 carries for 75 yards and one touchdown this week, consider betting the Under.

Or of course rather than rely on the work of others, you can handicap the prop yourself and make your own projection of how many yards you expect from Peterson this week.

Prop lines have the reputation of being among the weakest of lines that sportsbooks post. Typically sportsbooks treat them as something of an afterthought. They'll post some props based on the fact that their square customers seem to like them, and they'll keep the limits low so they can't get hurt too badly on them if they do happen to post some weak lines.

But the bulk of their brain power is going into setting their straight lines on major sports. For something like a Randy Moss receptions prop, a lot of times they won't do anything much deeper than "Moss has caught an average of 5.4 passes per game this season. He's going against a better than average defense this week. Let's put the line at 5 receptions."

So the opportunities are there. If you examine that situation in a lot more detail (maybe it's been reported in the local newspaper that the team intends to get the ball to Moss more than usual in upcoming games, maybe the specific cornerback who will likely cover him the bulk of the game is substantially better or worse than the defense taken as a whole, maybe even though Moss averages 5.4 receptions a game he almost always gets 4 or fewer but happens to have a rare 10 or 12 catch game to throw off the average, etc.), you may find that the Over or the Under is much the better play on that prop.

If you put the work in, you'll likely find some edges betting props. But beware, if you beat a sportsbook out of too much money on props, you may find yourself shown the door. Sportsbooks tend to be cocky about their main lines on major sports, and it'll take a lot of evidence before they conclude they can't beat you on those. But as I say, prop lines are more of an afterthought. Some sportsbooks will even say they offer them as a "courtesy" to their players, and have the attitude that there's a "gentlemen's agreement" that customers will bet mostly straight bets and just throw in an occasional prop bet here and there. If they see someone pouncing on a handful of weak prop lines each week for the maximum allowable bet, and betting little if anything else, they may not like it.

Of course now we're into the "problems it's nice to have" territory. If you're doing well enough at sportsbetting that you need to concern yourself with how to not get booted from a sportsbook for winning too much or winning on the "wrong" things, then you're doing pretty well.