Bob Greenwade wrote on Sat, Feb 24, 2024 04:41 PM UTC:
221. Spiral and 222. Plummet. This is a pair that I found courtesy of the British Chess Problem Society's Glossary of Fairy Chess Definitions. That document calls them SpiralSpringer and Diagonal SpiralSpringer respectively, but since I already have a piece called Springer, I decided to drop that part; and "Diagonal Springer" seemed so contrived and awkward that I consulted a thesaurus to find the opposite of spiral. Plummet is what I settled on.
For a change, figuring out the XBetza for the pieces was actually easier than figuring out how to describe the moves in text. Perhaps the simplest description of the Spiral makes a series of (1,2) moves in a zigzag of either 45° turns or 135° turns, with every other step directly orthogonal from the starting point. (Nabr(abz)Nafl(afz)N)
The blue arrows here show probably the clearest visualization of the Spiral's move; it can be interpolated to the other three orthogonal directions.
The Plummet does roughly the same thing, but moves so that every other step is directly diagonal from the starting point. (Nabl(abz)Nafr(afz)N)
Again, the blue arrows show the clearest visualization, which can be interp;olated to the other three diagonal directions.
While the Spiral does bear a superficial resemblance to the Springer, I think they're distinctive enough to tell apart.
221. Spiral and 222. Plummet. This is a pair that I found courtesy of the British Chess Problem Society's Glossary of Fairy Chess Definitions. That document calls them SpiralSpringer and Diagonal SpiralSpringer respectively, but since I already have a piece called Springer, I decided to drop that part; and "Diagonal Springer" seemed so contrived and awkward that I consulted a thesaurus to find the opposite of spiral. Plummet is what I settled on.
For a change, figuring out the XBetza for the pieces was actually easier than figuring out how to describe the moves in text. Perhaps the simplest description of the Spiral makes a series of (1,2) moves in a zigzag of either 45° turns or 135° turns, with every other step directly orthogonal from the starting point. (Nabr(abz)Nafl(afz)N)
The blue arrows here show probably the clearest visualization of the Spiral's move; it can be interpolated to the other three orthogonal directions.
The Plummet does roughly the same thing, but moves so that every other step is directly diagonal from the starting point. (Nabl(abz)Nafr(afz)N)
Again, the blue arrows show the clearest visualization, which can be interp;olated to the other three diagonal directions.
While the Spiral does bear a superficial resemblance to the Springer, I think they're distinctive enough to tell apart.