If I knew the guy and was aware before the bet was being made, I would have put something the other way against the bet. Least I could do so that I could buy some beer in consolidation if the bigger bet had lost. Its not really possible to avoid losses but I very much want to avoid the all or nothing approach just from the vast experience of how any game can end randomly and not the result it should have been or was most likely. In sports betting you can never tell if the players are tired out from travelling, distracted or just recovering in some way, injuries, anything at all can be the random factor that disrupts your idealized view of the game.
You are right, but then some (I should call them professional gamblers) still put all this you mentioned into consideration while casting their bets, it is true that a regular gambler like myself don't care to now what if the team are tired from traveling , or just recovering from illness, injuries or anything similar, most of us don't care about this things and also consider them important to have an impact on the outcome of a game, but the professionals do, and maybe that is what indeed makes them professionals - having to look at every angle and every and anything that could have an impact to the outcome of the game and betting according to the findings sure does increase the chances of winning, but I will still want to argue that it's not always like most would think.
