I'd use Sloane Square for Chelsea. Currently, my map of London is on holiday with my parents, who will be back Friday. I would suggest, however, investing about $7 in a laminated map of the city (available at bookstores) that has the city districts on it, as well as tube stations.
"Is ice hockey hard? I don't know, you tell me. We need to have the strength and power of a football player, the stamina of a marathon runner and the concentration of a brain surgeon. But, we need to put all this together while moving at high speeds on a cold and slippery surface while 5 other guys use clubs to try and kill us. Oh, yeah, did I mention that this whole time we're standing on blades 1/8 of an inch thick. Is ice hockey hard? I don't know, you tell me. Next question."