LOUISVILLE, Kentucky — Twenty horses stampeding toward the first turn in a battle for position. A screaming crowd of 150,000 and maybe some showers that dampen the Churchill Downs dirt strip.

It’s the 150th Kentucky Derby. Beyond a couple early wagering favorites, it’s a wide-open race.

Post time is 6:57 p.m. EDT Saturday. The forecast calls for 81 degrees with a 60 percent chance of scattered showers and thunderstorms.

That kind of weather could benefit six horses that have won in the mud or slop before, including early favorites Fierceness and Sierra Leone. The others with experience on messy surfaces are Dornoch, Just a Touch, Mystik Dan, and Society Man.

The Derby will answer the perennial question of which 3-year-old can best handle running 1 1/4 miles in front of the biggest crowd they will ever see and hear.

Fierceness and jockey John Velazquez will break from the No. 17 post, which has never produced a derby winner.

The costliest colt in the 20-horse field is Sierra Leone at $2.3 million.

“A lot of times you buy an expensive horse like that and they can’t run,” said Peter Brandt, one of the six owners. “We’ve very, very lucky he’s made it this far. We’re looking forward to this race but also looking forward to the future of taking care of this horse.”

Conversely, Larry Demeritte shelled out just $11,000 to buy Saratoga West. The 74-year-old Bahamas native has won 180 races and nearly $5 million in purse money since he started training in 1984. Demeritte is just the second Black trainer since 1951 to saddle a horse for the derby.

“This is truly amazing how we got to this position with this horse,” he said.

The Derby winner earns $3.1 million from the record purse of $5 million.

For the second straight year, Japan has two entries: Forever Young and T O Password. The country has never won the race.

This year’s race is one for the ages, too. D. Wayne Lukas, the 88-year-old trainer with four derby wins, saddles Just Steel. Frankie Dettori, the famed Italian jockey, is back to ride Society Man at age 53 after a 24-year absence.

Trainer Todd Pletcher, who saddles Fierceness, is in the derby for the 24th year and it never gets old. He’s won it twice.

“If anything, it just becomes more nerve-wracking,” he said.