I was puzzled when looking at the following puzzle:
lichess.org/training/I09CG
Luckily I looked at the previous moves before taking the key decision. Due to this I realized that 15.Ne5 Qh5+ 16.f3 Bxd4 17.Qxd4 was not the solution in view of 17...0-0!, when black is better. If castling was not legal, black would be lost in view of the threat of 18.g4 with an eventual mate on d8. Such puzzles look extremely tricky to me, as looking at the earlier game course is unusual when solving puzzles. Here it was almost necessary.
lichess.org/training/I09CG
Luckily I looked at the previous moves before taking the key decision. Due to this I realized that 15.Ne5 Qh5+ 16.f3 Bxd4 17.Qxd4 was not the solution in view of 17...0-0!, when black is better. If castling was not legal, black would be lost in view of the threat of 18.g4 with an eventual mate on d8. Such puzzles look extremely tricky to me, as looking at the earlier game course is unusual when solving puzzles. Here it was almost necessary.
