2 recent examples with baseball props:
They manipulate the payouts on parlays now. As with every book, they can change odds based on whatever they choose and that’s fine. The payout should be standard and shouldn’t change based on a player or team. A parlay of +400 and +400 should pay a standard +2500. Even if it they tweak it and want to lower it to f you, every parlay of the exact same odds should pay the same. Neither of these are true at FD. They use some unknown method to determine parlay payouts and it changes depending on the player. Have had some very weird situations where a +500/+400 parlay paid less than a +500/+350
They are also the only book that won’t void a no start in baseball. Every other book needs a batter to be in the starting lineup to play. FD does not and will keep the bet live even if a player pinch hits later and only gets one AB. You bet with the expectation of 3 or 4 AB rather than just 1. They stick you with a 1 AB play and with odds that are set like they were starting. If you live bet the 1 AB, your odds would be much better. You don’t get those odds. The most dastardly thing they do thought is they won’t let you cash the bet out and take your money back before the game starts. You have a parlay where all the legs haven’t started, they won’t let you void it once it’s been announced your player isn’t starting. They are the only book that operates this way.