In my experience when playing against other players on MP, specialist strategy works great under early representation (with pyramid, preferable playing a philosophical civ). Typically, my science would be 4 techs more than the closest civ at medieval, and I would be first to circumnavigate and discovered liberalism. Due to all the farms and mines (I only build windmill for science cities), as well as priest speciast/engineer specialist, my production would be number 1. Therefore, I can win any war I choose to get involved in, since my science is superior, therefore better units, and I can outproduce anyone due to my high production. As the game progress, a lot of people quit when they see how far behind they are. Around the age I get cavalry/cannons, I build a large army and attack the second leading civ, take/raze some cities, they can resist for a while, but eventually my better production overwhelms his defenses. If all the players quit, and I am left with all AIs, with me as the point leader, then I conclude my game won and exit, plus it is not fun to play against all AI in an MP game.