I explored bitcoin books and after researching i tried the 3 most popular ones and i am disappointed with the nature of bitcoin sportsbooks when it comes to long term winning bettors or high rolling winning bettors. I mainly looked into bitcoin books because they are touted as higher limits than normal fiat currency books. However, they operate just like the regular books. The decent bitcoin books simply lower your limits fast if you keep winning and the other ones are scam.

CloudBet  Vote = 0
This book owes me 30 bitcoins and forced me out. I posted my story is Swoky's thread https://bitcointalk.org/index.php?topic=5106313.msg49653094#msg49653094
I think they are ponzi scheme books that cheats high rolling winning bettors. They pay their small and medium winning bettors to generate positive feedback. Only 2% of all bettors are winning bettors. So many of the losing bettors don't know about their scam and will not find out until they win big and try to withdraw.  After my experience with this book, my conclusion is to never leave big balance in any bitcoin books even if they are rated good. You will never know what will happen until you win big as a high roller. Don't deposit very big amounts on bitcoin books based on feedbacks from small bettors even if that book has good standing! I personally stopped using bitcoin books alltogether after the experience with cloudbet

Nitrogen Vote =3
This book paid all my winnings and deposits but they are not suitable for me. I mainly joined them to follow the bettingresource.com's syndicate picks and they have them flagged. With in few days they will lower you limits if you use them only to follow BR's full stake tips. They are also slow to grade the bets. Often they don't grade the bets until next day and once it took 72 hours for them to grade an NFL bet.

Fairlay Vote = 3
This is similar to Nitrogen when it comes to limit. I started with 4 bitcoin limits in certain markets and soon they lowered to 2 bitcoins, then 1 bitcoin and now in that same market my limit is 0.5 bitcoin. But they paid all my money.