The 25% that is paid to the player comes off the top so for first place:
25,000 - Player
75,000 - Stakehorses
45,000 - Main Stakehorse
30,000 - Random Stakehorse
For 2nd Place:
15,000 - Player
45,000 - Stakehorses
27,000 - Main Stakehorse
18,000 - Random Stakehorse
The part I don't really understand, is why big $$ stakehorses are willing to put up so much to win so little. First is the only one that really wins much. The chances of one person getting 1st and 2nd is not that great.