I still haven't seen a bitcoin sportsbook that offers horse racing bets besides DirectBet.eu. So here's another point where "the best rated bitcoin sportsbook" succeeds the other bitcoin betting sites. I will be very glad if they would have a look on bet365 or unibet betting options on events so they could diversify the offers a little. e.g. How many corners will be in the game? OVER/UNDER or Will be a red card in the match? YES/NO or Goal scored in the first 10 minutes? YES/NO
Sports betting and racing betting are very different - the knowledge and technology required for one is entirely different to what's required for the other. If you're specifically rating "sportsbooks" then horse racing shouldn't come into it at all, maybe you could start a new thread specifically for horse racing? People might find it useful, and you could get some sweet, sweet affiliate referrals! As far as the props you mentioned, it used to be possible to bet on those at some books, I wonder why it's not any more.