Talking of "styles" of this or that engine....

[fern]

Style tend to be, in chess, the specific kind or shape of the game that usually comes from the regular mistakes or imprecisions committed by the player with "style"..
If there is in any position ONE move that is better in terms of getting most advantage with less effort, then any deviation of that becomes "style". The extreme range of deviation becomes just sheer mistakes.
So when I hear of this or that engine has "style" I guess at once that it is not in the top five league in terms of strength.

Fernando

[Ovyron]

You're talking about the theoretical "Optimal Move", that maximizes winning chances. However this requires opponent modeling (the optimal move against a human can be different from one against a computer) and possibly solving the game (because there's no way to know what's the optimal move as is, what seems optimal today may be a blunder in the future when stronger opponents are available.)

Ironically, it's been said that Rybka's strength doesn't come from playing optimal moves, but from avoiding bad moves. She's so extraordinarily good at that that the opponent will play a bad move first most of the time, even if the percentage of optimal moves from the opponent is higher. one bad move loses the game an the rest loses relevance.

[fern]

I talk of the best move according to current knowledge, the same kind of analysis that get us to re-write opening books from time to time. Even without solving the game, in a given position there are better moves than others though they are not, perhaps, the best.
GM play those better moves. Patzers, with "style", play lesser moves and lose.

My best
Fernando