I was looking at the example below of what Guo Juan calls a "bad trick," which is what she calls trick plays that, if your opponent knows the trick, lead to a bad result for you. (For reference, "good tricks" are those that don't leave you in a terrible position even if your opponent responds appropriately, although it may not be optimal).
Here is the trick move:
And the sequence black wants:
Black can kill at 'a', so white takes, and black commences a painful attack at 'b'.
White's position is better after responding to
as follows:I first saw this around 8k or so, and had trouble understanding how this is bad for black. I won't go into detail, but it was eye opening for me to compare it to the following joseki:
All of this makes sense to me. I'm confused because pros often play the "wrong" response. In fact, from the position in the second diagram, pros play the "wrong" move more often than the "correct" move (admittedly a small sample-- 20 times vs. 15 times in my database). I assume that, if black plays the hane (at Q17 in the diagrams above)--which is played very rarely--he has already determined that white's position after the appropriate sequence is acceptable. So I also infer that these are special cases.
But I can't see what's so special about most of these games that makes the "wrong" move okay. Of course, I very seriously doubt that this move is actually "wrong" in these games. But I'm not sure why.
Here are two samples in which the move was played by Yuki Satoshi and Kitani Minoru:
