A projected $55 million-plus lottery prize that would return the North American title for big jackpots to the state is making Californians' gambling fever rise again. Lottery officials and merchants said ticket sales for the Saturday drawing were running about double the usual pace for Thursday's sales. The official estimate of ``over $55 million'' for the drawing is conservative, based on similar situations in the two-year history of California's computerized Lotto 6-49 game, said lottery spokesman Bob Taylor. On June 4, California's lottery paid out a $51.4 million jackpot, North America's largest at the time. That jackpot was eclipsed Sept. 3 by a $55.1 million prize in Florida. The state-run lottery's policy is to estimate the jackpot conservatively, then revise the projection upward as sales soar. It all depends on how wildly Californians react to the 1-in-14-million chance of winning the jackpot. ``The jackpot is going to generate an awful lot of sales,'' said Taylor. The size of the jackpot depends on sales and jackpot rollovers, which combine to produce heavy gambling periods, dubbed ``lottomania'' when they first struck other state's games. When nobody picks all six winning numbers out of a choice 49, the jackpot is rolled over, or added, to the top prize for the next twice-weekly drawing. Four rollovers, including the rollover of a $33.4 million jackpot Wednesday night, produced the current record prize estimate. The exact size of the jackpot will depend on how many tickets are sold. Of every $1 ticket, 20 cents goes into the jackpot. Each time the jackpot climbs, so do sales, pushing the total still higher, generating even more sales. Historically, most of the sales occur in the last few hours before the televised drawing at four seconds before 7:57 p.m. Sales are cut off at 7:45 p.m. By 2 p.m. Thursday, sales hit $1.2 million, which is normally the total for the entire 7 a.m. to 10 p.m. sales period on a Thursday, said Taylor.