You simply won't be able to exactly tell how long that fight might last, sometimes you won't even be able to tell if you're going to win. You might have an idea about how long it should last, but there's so many different options on both sides that no "Level XY" fighter is the same as the other. Individual actions, individual equipment, individual individual levels (*g* I like that one...), individual use of skillpoints, individual tactics, melee or magic or both...
And then, ofc, there is the beast of level XY you're looking to fight... carnivore or herbivore, kitin or not, dodge or parry, armored vs. slash, smash or pierce, resistance vs. which kind of magic, ...
Unless you're fairly overpowering a mob, better even that mob and a few of his buddies at the same time, you'd hardly be able to really tell how a SvE (Solo vs. Environment) encounter will end exactly. Isn't that sweet?
