Let's see, of the 20 seasons, the winner of the first leg won the Race in season 1, season 10, season 13, season 15, season 19, and season 20.

Odds based on all seasons: 6 of 20

Odds based on 10 most recent seasons: 4 of 10

Odds based on seasons since reduced legs from 13 to 12 (season 13-20): 4 of 8

If they're trying to motivate teams, I fail to see how that would happen after the first leg if only the one team can win the higher amount.