Tim Krabbé's book "Schaakkuriosa" showed a study by the Bulgarian chess composer I. Ionchev, flawed but nevertheless interesting. Yours truly tried to follow in his footsteps. Nadareishvili explored the same concept, and it might be unfair to associate the name with Ionchev as he was neither the first, the last, nor the most important one to show it - only the most famous. | Photo: Pixabay