I hate "decisive battles". Especially when you try to compare it with the entirety of Human History.
Firstly, I hate these things because by right, every action and event ever is a decisive action in changing the face of the current time frame of human history because preceding every event, is another event that could only happen because of a preceding one.... <Put point between two mirrors>
When we say something is decisive, it is at that moment where it is an either or situation. You either pick the red pill and situation 1 happens or you pick the blue pill and situation 2 happens(often there are a lot pills and resulting situations as a well). But clearly, for something to be decisive, it needs to be a now or never moment. A point in time where whatever the decision picked, it is impossible or at least, incredibly hard to turn back and pick the second option.
Often in History, that is not the case. Most wars do not consist of two opposing sides with only one equally sized army for attack/defense each that results in a battle in which the complete destruction of one side's army happens.
It's often a series of battles and campaigns and a series of factor aside from one battle that results in Final Victory. Napoleon was finally defeated in a 50 different battles, not in one battle. Hitler wasn't finally defeated at Stalingrad, he was defeated in hundreds of battles across Europe. And this is if you dismiss economic, social and supply factors.
Decisive battles in the face of human History are in my opinion illogical. There are some battles that are more important than others, but in most cases, there are never decisive battles.