En/na Antonio Torrecillas ha escrit:
(...)
it seems tactics too!

AT

Sure that "positional tests" have tactic component too but I think the
original poster was searching positions like this one:

(extracted from "The best Move" by Vlastimil Jansa and Vlastimil Hort)

Cucka-Jansa, Brno 1960 (Black to move)

r3k2r/3bbp1p/p1nppp2/5P2/1p1NP3/5NP1/PPPK3P/3R1B1R b kq - 0 1

Where the solution is:

(spoiler for people who want to solve it before reading the solution)
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The white treat is 2.Bc4 or 2.Bh3 atacking e6.
If black has to advance or change his e6 pawn, d5 will be very weak.

1...Bf8! 2.Bc4 Ke7! 3.Ke2 Bh6 and ... black is better because he has the
pair of bishops (in good diagonals), a good pawn structure and has
connected his rooks.

After some other 1... moves black can experience difficulties and can
reach a worse position.

AT

Pd: The Jansa&Hort book is one of the most interesting tests in that sense.