It always the coach, we know sometimes players have effect on these results but it left for the coach to put in the good players and make sure he get the result he want.
The coach is at fault because the main player was stupid and spent the last 2 days before a game secretly partying? Brilliant. 
I agree that the most important point is to be prepared to lose the money we bet, so that when predictions go wrong, we don't have to look for scapegoats to blame.
This has nothing to do with the topic.If a team performs poorly in just a match, then we shouldn’t blame more than the coach and the players, but if it’s continues, then we have to blame the players, coach and the management, maybe the management isn’t providing what the coach needs to improve the teams performance.
Perhaps the fact that you need people to micro manage you indicates a problem with yourself instead of a problem with the management? Many adults are in fact still children, and it is a very similar situation in large corporations. You need to treat many adults like children for them to work properly.