A Powerball win is getting closer to being a sure thing — for someone. That’s because the army of dreamers who have bought tickets are moving closer to buying all the game’s possible combinations.

A total of 292,201,338 possible combinations exist for the lottery game, which allows players to choose five numbers between 1 and 69 and a sixth number, called the Powerball, from between 1 and 26.

At the time of the last drawing on Saturday night, more than three-quarters of the possible combinations had been purchased. Still, no one won.

Lottery officials representing the Multi-State Lottery Association, which runs the Powerball game, expect that for the drawing Wednesday night, about 85 percent of possible combinations will be purchased.

The Powerball jackpot had grown to $1.5 billion on Tuesday after a series of 19 drawings in which no one picked the lucky combination.

In the early going, fewer people were attracted to the smaller jackpots — and thus fewer number combinations were bought. As the jackpots ballooned, more people have played, resulting in more number combinations being covered, lottery officials say.

Less than 5 percent of the possible number combinations were purchased nationwide for the first eight drawings as the grand prize rose from $40 million to $110 million, according to figures provided by Massachusetts State Lottery spokesman Christian Teja.

But things have changed now. In the past two drawings, the jackpots have reached mindboggling proportions and drawn increasing media attention. The number of people playing and number combinations covered has increased sharply.

When the jackpot reached $500 million for the Jan. 6 drawing, about 45 percent of the possible combinations were played. And on Saturday night, 77.8 percent of the combinations were covered.

Lottery officials said they were not sure what the record is for the highest percentage of combinations in play before anyone won.

Matt Rocheleau can be reached at matthew.rocheleau @globe.com.