Well, since the necromancer allready cast his spell.....
I've been playing a lot online lately.
However, this is partly because I like the social aspects of playing as well as the fights. You can talk, lay plans, and see them smashed or succeed,
To illustrate, Napoleon Total War. Me and a friend started playing, he Prussia, me Russia. I started fighting the Ottoman empire, he joined in, and I asked him to help kill an ottoman army that was creeping towards Kiev. He rerouted to attack that. We usually cooperate.
Now, in Napoleon, you have a strange but interesting - even good - solution to the problem 'downtime' during tactical battles. Basically, a player not involved in the current fight can take over for the AI.
Of course, there is a risk of ... divided objectives. When he fought to help me defend, my incentive to trounce him on the battlefield is not all that great, but I put that aside well enough. He had too large forces for the small ottoman force to defeat, but I did manage to destroy a couple of high value units. We did have a gentleman's agreement not to use artillery on generals. (cannons seem to be good snipers.).
Later, when I attacked and he played defensive for the ottomans, I flanked his armies, and basically annihilated a huge army with just symbolic losses. Six artillery batteries forced him to engage or flee - and as he couldn't mass his forces (flanked) they were destroyed piecemeal, usually before firing a shot. And he couldn't run, as he was defending a city.
And he was furious, and frustrated, ranting about how he never won a fight without having tremendous overweight in forces.
That's okay, really, I'd be annoyed myself at a few of those, but that was while we were fighting cooperatively. If it'd been VS, it'd be even worse. I don't play games to grind someone into the dust, I play them to have fun - and it's not fun to have your friends annoyed at you for crushing them, or being annoyed at them, for that matter.
So, basically, I play singleplayer or multiplayer (coop) almost exclusively.
Is that because I am afraid of experienced players? No, not at all. It's just that that's not what I play the games for.