As you learn how to become a profitable sports bettor, you may either read or hear the advice that betting home underdogs is profitable, or have started to suspect that this may be the case from your own betting outcomes. The first time I read about betting home underdogs was quite a few years back and it was mostly profitable at the time.
However, things have changed. While you can still find profitable situations where you can bet on home underdogs, you can't blindly do it and hope to win in the long run.
The same thing happened that always happens when a large enough group of sharp sports bettors starts winning too much money from the sports books using any particular method. The books learn what the best bettors are doing and then take action to either take away the sharp player's advantage or determine a way to convince enough money to wager on the other side that it doesn't matter.
In the case of betting on home underdogs, the sports books know that some players bet them without considering many other game factors so the books adjust the lines. A line that may have been home team XYZ at +6 ten years ago is more likely to be home team XYZ at +2 now. The sports books will keep moving the lines until they find the place where they make the most profit.
Never make the mistake of assuming a sports book wants to have a line that is as close as possible to predicting the final score. The number one rule of any successful sports book is producing the most profit. While making the most profit and producing betting lines that closely predict the difference in a final score often go hand in hand, they are not always the same thing.
Here is a perfect example of how the two things don't always go together. The Ohio State football team has hundreds of thousands of loyal fans and many of these fans bet on the Buckeyes, no matter what.
If you run a sports betting operation in the heart of Ohio State football territory, in order to make the most profit you will adjust the line against the Buckeyes on every game to take advantage of the mass of fans that will still make the bets. In this case you don't want your final line to be accurate. You want the original line to be accurate so you can win all of money bet on the poor line that has been adjusted.
There are generally two ways the sports books make money. The first is being in position to make money when the majority of money wagered by the public is on a poor value. The adjusted line on the Ohio State football games is an example of a poor value wager.
Sharp sports bettors will take advantage of the adjusted lines and bet the other side. Sports books keep a close eye on how many sharps take the other side. If too many start betting it they may adjust the line back a little bit.
The other way the sports books make money is by charging vig on every game and creating a situation where the same amount of money is wagered on each side of a game. The sports book profits from the vig no matter who wins when the amount of money wagered on each side is even.
So why don't the sports books always want the wagers balanced? The answer is when it is more profitable to offer an adjusted line that creates more money on a poor bet.
Well run sports books make enough money that they can afford to have more money on one side of a line than the other if the money is on the side that offers the book the best value. Here is a final example, using the Ohio State example listed above, to show how the book profits in the long run on these types of situations.
The original line has Ohio State favored by 4, but the bookie located in the middle of Ohio has adjusted the line to Ohio State favored by 8. On average, if the same game is played 100 times Ohio State will win by around 4 points. They will lose a few times and will win by 20 a few times, but on average the final margin of victory is 4.
If the book has $500,000 wagered on the Buckeyes and $100,000 wagered on their opponents, they stand to lose a large amount when Ohio State wins by 9 or more. But Ohio State will win by 7 or less most of the time. They will win by 7 or less enough of the time to make enough money to cover the few times they lose and still leave enough for a healthy profit.
You need to use the same solid methods to decide whether or not to bet on home underdogs as you use to make any other wager. I always consider the home team being an underdog as a factor, but I never use it as the only factor.
In baseball you still need to consider the starting pitching matchup, injuries, weather, current streaks, etc. When you are betting on basketball you need to consider the recent schedule, travel distances, injuries, etc. In football you must consider injuries, coaching, travel distances, etc.
On top of everything else you need to try to determine if the line has been adjusted to manipulate you to take one side or the other. The bottom line is you still need to find a line that offers value.
Everything a sports book does is designed to make the most profit. Use this knowledge to find lines that offer the best value, whether they are home underdogs or not.