Well, what's your opinion on Emperor Napoleon I? Is he the best military strategist that ever lived? All of the documentaries I've ever watched seem to think that that's the case. I personally think that he was great at manipulating the environment to his advantage, sometimes. I just feel that he acted on impulse, sometimes coming up with genius ideas, other times not so much. What do YOU think about Napoleon Bonaparte? Genius or moron or somewhere in the middle?
*raises hand* I'm not here much any more, but... well... this is sort of (one of the things) I went to university to study and is a long-standing personal interest. My take:
Genius, but he had a long career and the insights of a genius can be learned by less brilliant men once they've been demonstrated.
He once quipped that you shouldn't fight the same enemy too often lest you teach him all of your tricks. Unfortunately for him, Napoleon didn't follow his own advice and fought everyone many times over many years... especially the Prussians and Russians.
Napoleon's biggest insights came in the field of logistics. His army was structured out of corps which were themselves mini-armies, capable of independent maneuver, detachment, and full operations. He could disperse his army for distance marching, secure that no part was more than a day's march from another corps, yet able to utilize a greater percentage of the available transportation infrastructure to move prior to concentrating. In other words, he figured out to how to move very large armies long distances very rapidly without significantly increasing their vulnerability to attack.
Problem was... by the end of the Napoleonic Wars, everyone else was doing the same thing... especially the Prussians and the Russians.
What I understood from my history lessons in school was that Napolean was genius regarding army logistics. He knew how to keep up the flow of provisions needed to supply his army and how to quickly move an army to another location.
Regarding field tactics: he was a very clever man. But if I remember correctly he won very few battles of all the battles that took place during the Napoleonic War, so...
Napoleon had no reason to believe that Russia wouldn't negotiate after a major loss, like the last two times he'd fought them (Austerlitz and Friedland, respectively).
When Alexander didn't sue for peace after Smolensk, or Borodino, or the loss of Moscow, it's only then that Napoleon might reasonably have assumed he'd made a mistake.