It's just that my past experience with Goodyear in general has been that they may provide a high ultimate grip, but they have a pretty abrupt break-away point when they start to loose grip when compared to Michelines, Yokohamas, BF Goodrich, and Firestones I've had the pleasure of abusing.
A little perspective from a rear wheel drive car:
You are in a corner near the edge of traction, and you give it a littler more juice, not enough to break the rear tires loose, but enough to unweight the front end a bit. Result the front tires don't have such a good grip on the road and they start to skid a bit, not turning the car as much as they would for the amount of turn you have dialed up with the steering wheel.
Oversteer: You are in the same corner and you suddenly chop the throttle, thereby applying rear braking via engine torque. Resulting weight shift loads the front wheels which grip and turn you as the rear wheels get light and loose their grip and come around in an attempt to pass the front tires. The car turns more than the turn set by the steering wheel.
You can choose between oversteer and understeer merely by what you choose to do with your right foot.
Of course most cars have a natural tendency to understeer as it is considered safer for most drivers. Eg my chevy wagon has severe understeer built in; that only makes it harder to reel the back end back in if it gets away from you while your drifting around your favourite corners.