He is lucky and almost always wins his bets.
FYI - Simon Wheeler does not suggest to the stranger that they bet on his frog. Simon Wheeler is the one telling the story about Jim Smiley and his frog Dan'l Webster. Dan'l Webster is the frog that is a great jumper so it's a good bet. However, the stranger fills Dan'l Webster with shot so he can't jump high and Smiley loses the bet.
Could you post the lines of two and four so I could see what they look like?
Since I don’t know what I’m responding to, therefore no one can answer that.
Appeal to emotions would be the answer. It isn't logical or appealing to any type of authority. It also doesn't have to do with reasoning so it appeals to the emotion of wanting your friends' to be jealous.