Maybe the house doesn’t always win, but it wins more often than you do and a lot more, too.

There are a lot of sayings and clichés that are thrown around in gambling circles. Perhaps none are more famous – or more believed – than the old adage that “the house always wins.” Of course, we know that some gamblers do manage to come out on top…but how often does that happen, exactly?

That was one of the questions that researchers at the Harvard Medical School sought to figure out in a new analysis of both online and live gambling patterns. The group was given the records of 4,222 online gamblers who played for at least four days on websites run by between the years of 2005 and 2007.

Less Play, More Wins

As you might expect, gamblers had a better chance of coming out ahead the less they played – after all, in games where the casino has an advantage, the house always wins in the long run. But in shorter stints, gamblers have quite a good chance of leaving the casino ahead. On any single day of gambling, it turned out that quite a few players had made money about 30% of the time.

Those numbers dropped over the entire course of a gambler’s time on the sites. By the time players had finished playing for good, only 11% were ahead of the casino. And of those who were ahead, most took home less than $150 in profit.

Also not surprisingly, the numbers were especially bad for players who spent a lot of bankroll on gambling. Of the 10% who were the biggest high-rollers, only about 5% managed to come out on top, with some losing tens of thousands of dollars. A random gambler was 31 times more likely to lose at least $5,000 than win $5,000 over the time period covered in the study.

Thus why casinos are profitable, children.

Big Winners, Bigger Losers

That doesn’t mean there weren’t success stories, though. One gambler, a 56-year-old Slovenian man nicknamed “Gambler No. 1381787,” managed to hit two large jackpots and win about $22,000 during his time on the site, making him the biggest winner in the study. Meanwhile, the largest loser in the study was over $110,000 in the hole.

Again, why it is not rocket science that casinos make oodles of dough overall.

The study also looked at where the casino site made its money. About 2.8% of customers were responsible for half of the casino’s profits, while 10.7% of customers gave the casino 80% of their take.

These numbers were then confirmed to be similar to those in live casinos. Using data collected from an unnamed Native American casino in the northwestern United States, researchers found that 13.5% of gamblers came out on top in the long run, a similar number to the online data (the small difference may be due to the fact that live casino play proceeds at a slower pace, so gamblers are playing fewer games). In addition, 9.3% of gamblers at the live casino provided 80% of the revenue, again similar to the online data. And now you know why their suites and meals are comped, hello.

The study also showed once again that poker – a game with a large skill component – bucked these trends significantly. Although researchers couldn’t isolate a player’s skill level, they could look at the amount of time players spent at the virtual poker tables. About one-third of the “most involved” poker players were able to win money in the long run, while only about 10% of casual players ended up profiting over time.

Moral of the story?  There are two: maybe the house doesn’t always win, but it wins more than you are likely to, by a good bit, over time. Also, you can go to an Ivy League medical school and tell your parents your gambling habits fall under the “research” category now.