Good point, I also wonder about the potential to exploit the algorithms used by the "professionals." In other words, if you can come up with a reasonable approximation of what the pros will do, can you use that information to beat them?
'Theoretically', no. Its hard to be optimistic about these two ideas because while the chess example is a good story, its not analogous for many reasons, ranging from disparity in available information to players to a difference of several magnitudes in saturation. Not to mention HFT just isn't chess.
HF traders are just as much hackers as anyone on HN (and there are plenty of HF traders on HN). So 'theoretically', they've already done what is being suggested here. If someone comes along and develops a winning strategy, it really shouldn't be considered as having anything to do with 'professional strategy vs novice strategies'. It would just be about one person either getting really lucky or coming up with something that is genius in its own right.
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If there are 'professionals' and then other 'professionals' whose strategy depends on information about how other 'professionals' trade (and there is), you end up with strategies at all valid points in the sample space of possible strategies and counter strategies. Theoretically, there should be no other possible strategies. Inevitably someone will come up with one though, and the 'sample space' will grow. But its extremely unlikely that additional unique strategies are successful just because they 'counter' the strategies in the sample space. But then again, this is real life and these things aren't impossible.