If you buy a lottery ticket, you’re probably already familiar with the odds of winning — but what you might not know is how much your chance of success depends on the numbers you pick. For example, if you choose all even numbers or all odd numbers, your chances of winning are far lower than if you spread out the groups. In fact, choosing random numbers will improve your odds by about 60%-90%, according to lottery experts like Richard Lustig, who advises players to chart the “random” outside numbers on their ticket and look for singletons (a group of digits that appear only once).

When it comes to picking the right number, many people try to follow advice such as “pick the birthdays.” But that is a bad idea because numbers that repeat tend to have more patterns, which can ruin your chances of winning. Instead, Clotfelter recommends using the computer to pick your numbers — which will increase your chances of winning by about 20%.

As states rely increasingly on the lottery as a source of revenue, it’s worth considering whether the gamble is worth the cost. Lottery advertising, for instance, necessarily focuses on persuading people to spend their money, which can lead to negative effects for the poor and problem gamblers. And because state lotteries are run as businesses, their managers are typically at cross-purposes with broader public policy. The result: Few, if any, states have a coherent gambling policy.