LOUISVILLE, Ky. (AP) — 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 (27 Celsius) with a 60% 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.