A great uncle of mine had made a similar but simpler game like this we used to play, decades & decades & decades ago. He didn't take credit for it, but he'd gotten it printed on a huge nice sheet of paper, and had horses that advanced down it. You just place bets and turn over cards for each horse, and the highest card horse advances. On rainy days we'd sit in the living room, my sibling & I, basically on top of the giant horse race game, making bets & turning over cards to see who the winner would be.

Our game was shorter, and only had uhh 6 tracks I think. The odds rose quite a lot for the un-favored horses, like, a lot a lot. The horses/tracks all had names, but I can't remember their names.