The term jackpot is used to describe a large and unexpected financial win. It is a common expression for the lottery winner, but also investors who back a company with an initial public offering and see the stock price skyrocket, making them multimillionaires overnight. The use of the word in these instances has broadened the meaning to include any sudden and large gain. However, the odds against hitting a jackpot are astronomical. In fact, you are over 20,000 times more likely to be struck by lightning than to hit the lottery.

Lottery organizers have been making the games harder to win for decades, says Victor Matheson, an economics professor at the College of the Holy Cross. This strategy increases the size of the prize pool and incentivizes people to buy tickets. “If there’s no winner, it rolls over to the next drawing and keeps growing,” he says.

But if the odds are too low, ticket sales decline. To prevent this, some lotteries increase the number of balls in a drawing or change other factors, such as lowering the payout percentage. Then there’s inflation, which affects how much the prize will be paid out over time. “When interest rates are high, it takes more money today to provide annuity payments in the future,” Kovach says.

Some people also try to improve their chances by joining a lottery syndicate, which pools players’ money and purchase more tickets and numbers, increasing their odds of winning. This strategy, which is legal in some states, may or may not work for you.