>> "Computing power doubles every two subjective years of work."
> Ok. Given this idea, if my brain were reprogrammed to run twice as fast,
> would my backhand be effected?
At the moment the quality of your backhand has nothing to do with the speed your brain runs at, so there is not likely to be any change. However, if you were an AI (or an upload, or any other sort of entity capable of doing internal re-wiring) things would be a little different.
A tennis-playing AI would presumably contain software for predicting the flight of a tennis ball, controlling the motion of its arm, observing the actual state of the game via its sensors, making abstract strategy decisions on the fly based on the situation and the rules of the game, and relating all of these different modules together so that it can actually act in its decisions. If the AI plays on the same level as a human it is likely that this whole assemblage has trouble keeping up with actual events in a real game - that is, after all, one of the criteria with which we separate "interesting" games from "boring" ones.
If you double the available computing power, you can go back and look for bottlenecks in all of these modules. You can speed up the flight-prediction module so that it gives an updated result the instant your opponent's swing is complete (or even before then, based on the trajectory of his racket). You can run the strategy module faster, so you actually have a chance to think about what to do. You can improve the precision of the whole motor control subsystem, so that your swing is less likely to miss and more likely to actually cause the trajectory change you want. You can try out all these ideas, along with dozens of others, and then pick the ones that turn out to have the biggest effect on your game and keep them.
If you think of intelligence enhancement in terms of improving some abstract, nebulous unit of "intelligence", it can seem rather improbable. If, OTOH, you think in terms of improving your ability to perform some concrete task, the way to proceed tends to be obvious for any field that we have even a modest understanding of. The contention of the "strong-SI" camp is that this trend is likely to hold for those aspects of intelligence that we do not yet have any understanding of, at that we should therefore expect an exponential increase in processing power to make possible a rapid increase in the effective intelligence of an AI.
Billy Brown, MCSE+I