The Novotny theme is probably one of the oldest ideas in chess compositions. The mechanism is due Antonin Novotny (1827-1871) and is related to the Grimshaw interference. The idea is the following: if a rook and bishop's lines cross each other, at a square called the critical square, then if white places a piece on the intersection of the two lines it will block both lines so that white can exploit this. The key usually makes a double threat and the captures of the key piece force the individual threats (not always though!). Since the Novotny's have been around for close to two centuries, problems that have only a Novotny mechanism are generally not very interesting. However, when combined with other ideas the Novotny has given rise to a large number of excellent problems.
On the side I like to dabble in chess problem composition. I am mostly interested in two and three move direct mates. I hope to convey the beauty and logic of chess problems with this blog. In the entries are some of my favorite problems and my own problems. Before looking at the problems I suggest reading this introduction to the chess problem world by the British Chess Problem Society. Also, here is a list of terminology and themes. Here is a link to my problems on yacpdb.
1. "Choose wisely" The Problemist Supplement, Sept. 2016
2. "Double checking white in a two mover" StrateGems July 2016
3. "Double check without capture" The Problemist Supplement, January 2018
4. "The disappearing Nowotny: Part I" The Problemist Supplement, March 2018
5. "The disappearing Nowotny: Part II" The Problemist Supplement, May 2018
6. "The disappearing Nowotny: Part III" The Problemist Supplement, July 2018
7. "Castling with half-battery and Fleck themes" StrateGems, July 2018
8. "The Baku Nowotny" StrateGems, January 2019
9. "The Romanian Nowotny with Fleck" The Problemist, March 2019
10. "Mirror Image" The Problemist Supplement, May 2019
11. "White King in Check" Problemas, July 2019
12. "A Simple Mechanism", StrateGems, July 2019
13. "Miniatures with castling and (partial) Fleck" Problemist Supplement, September 2019