How does the stranger trick Jim Smiley?

The stranger tricks Jim Smiley by betting him that he can outsmart Jim's trained frog, Dan'l Webster, who can supposedly jump higher than any other frog. The stranger secretly fills Dan'l Webster's mouth with quail shot, making the frog too heavy to jump when the contest begins. As a result, Jim loses the bet, not realizing he's been deceived until after the stranger leaves with his money. This highlights Jim's gullibility and the stranger's cunning nature.