~ Z ~ said:
The man who has everything to lose would win. This is no question in my opinion. I see things like this.
Man B has everything to lose (In this case, his family) vs. Man A who has nothing to lose.
Man B has pretty much every reason to fight to the death to protect his family. That alone should be enough for anyone with any reason to fight to their fullest, regardless of strength or not. He has every reason to fight with all his might and all his endurance. I mean... his friggin' family is on the line. This one should be pretty obvious.
Now, Man A is left with two options: Fight and kill the man or lose. What's the reward for doing either action? Nothing. Think of it like this: If Man A wins, he gets nothing, if he loses, he gets nothing. Either way, he will get nothing. Nothing gained nothing lost. Why is this important? If he lost it wouldn't change anything so what difference would it make in the fight?
So it all comes down to this: Guy who's family's about to get killed vs. A guy who had a bad day... Who do YOU think is gonna fight to their fullest potential without adding some extra stuff to what is presented?
Because, again, you're talking about a scenario where the man that has nothing to lose is fighting all out without restriction on care for his life, his family, etc. He is motivated effort wise to give his fullest, given the scenario presented from "had a bad day and isn't taking anymore" and his lack of empathy towards something. So his is fighting at a theoretical 100% because motivation is balanced in the fact that he has nothing to hold back and nothing to spur him forward. If his motivation was theorized as nothing, then this fight wouldn't even be occurring at all. So the assumption that he is fighting apathetically is misguided: he's given motivation in the scenario that debunks that theory.
The difference comes in the man with everything to lose: he is going to be fighting for more than himself. So rather than simply 100% from the man with nothing to lose, he has the added bonus of fighting for his family, his honor, whatever excuse you can think of that would be of value. He literally has everything to lose. But the drawkback is that while he has this increased motivation to fight, it can also be a burden. Pressure and anxiety are factors that apply to individuals in a unique sense of character: some people can handle it and use it to their advantage in a situation to thrive. While others feel the burden and come up short, IE, choking in a very important sports game.
So there is no "clear" answer without adding something here: one side is at 100% at all times, while the other can be 150% or as low as 0% in the variable regarding someone's capability to handle pressure. Fairness wise, only one of those variables remains consistent at all times: the man with nothing to lose.