This is a big-list question regarding chess themes (mostly tactical). There are some puzzles that illustrate important aspects of a tactic (esp. useful in a chess coaching setting). For example, the following puzzle speaks volumes about pin.
[Title "Adapted from Schatz vs. Giegold, Hof (1928)"] [FEN "7k/pb2q3/1p3p2/2prp1p1/6P1/1P1R4/PQ3PP1/1B5K b - - 0 1"] 1...Qh7+ 2.Rh3 Rd1+ 3.Kh2 Rh1+ 4.Kg3 ( 4.Kxh1 Qxh3+ 5.Kg1 Qxg2# ) 4...Qh4+ 5.Rxh4+ gxh4#
Credit: Adapted from Martin Weteschnik, Understanding Chess Tactics.
In particular, the puzzle illustrates creating a pin, and that absolutely pinned piece can move and bring about surprises.
Include only one puzzle per answer. The value of an answer should be decided by the following:
- How good the puzzle illustrates various points of the theme (mention the theme and the specific points of theme illustrated by the puzzle).
- How beautiful and/or surprising the puzzle is.
To be clear, the difficulty of a puzzle is a demerit if it becomes a hurdle for the puzzle to illustrate the theme to most of the audience.
Also, include the details of the game or the composition.