I’ve tried lots of different sportsbooks for horse betting and bet on Kentucky Derby multiple times too.

I would say the best for Kentucky Derby is Mybookie sportsbook.

They have great odds compared to other sportsbooks, lots of betting options and they have kentucky derby promos too. Give them a try.

I've had some luck with betting on horses that perform well in specific weather conditions. Check the weather and track info on Bet365 before placing your bet.