What makes a chess puzzle hard to solve? A couple friends and I built a mobile app (Chess Puzzle Blitz) where we allow people to compete for fun or money solving chess puzzles.
We have a pretty large puzzle database but are always adding to it.
One thing we keep iterating on is the types of puzzles we surface (currently only mates 1 through 5 (usually 1-&gt;3). For example, one feedback we got early on is that black puzzles are harder because of the mental switching between puzzles (so we rate black puzzles harder in that context).
For you, what makes a chess puzzle a good puzzle and what elements make them hard/frustrating?
Each player has his own form of tactical blindness, so &quot;what makes a problem difficult&quot; varies from solver to solver. If one of the key moves is backward-going, I'll never find it.
Some players forget that when they move a piece within their calculation, it no longer covers the squares it did before.  Some players have a hard time counting multiple exchanges on the same square. Different for all.
&quot;Black puzzles are harder&quot; is silly. Chess pieces are only light and dark for convenience. The pieces could all be the same shade of gray, and chess could still be played as long as the players remembered which gray pieces belong to which player.
When it's &quot;Black to play and win&quot;, flip the board so Black's on the bottom of the diagram, and you will find them just as simple to solve.