One popular branch of chess variants is Capablanca Chess. Originally proposed in the 1600s by Carrera, and proposed again in the 1800s by Bird, and propsed yet again in the 20th century by Capablanca, this is one of the more popular types of chess variants that people have proposed versions of.
There are some 126,000 possible Capablanca opening setups, where the bishops are on opposite colors, and where the queen is to the left of the queen. However, looking at all of the Capablanca opening setups which have actually been proposed, I have observed that:
- All of the opening setups have the king and a powerful (R+N,B+N, or Queen) piece in the center files
- All of the proposed opening setups are symmetrical with the rooks, knights, and bishops
- All of the proposed opening setups have the rooks either in the corners, or one file closer to the center than the corners.
Here is a list of proposed Capa chess setups I know about:
RNBAQKMBNR Capa 1 (1.Mh3 mating threat)
RNABQKBMNR Capa 2
MRNBQKBNRA Paulowich 1 link
ARNBQKBNRM Paulowich 2 link
RNMBQKBANR Nalls link
RNBQAKMBNR Teutonic link (1. Mh3 mating threat)
Any without a link here are listed on on the Capablanca Chess Wiki page.
And some more proposed opening setups, since not nearly enough Capa opening setups have been proposed :)
Setups which suffer from white being able to threaten mate on the first move:
BRNAQKMNRB Mh3 (Capa 1)
RNBQAKMBNR Mh3 (Teutonic)
So, for aspiring Chess variant inventors, that leaves us with the following possible Capa opening setups:
QRBNAKNBRM RQBNMKNBAR NRBQAKMBRN RBNQAKMNBR NRBMQKABRN BRNMQKANRB RBNMQKANBR QRBNMKNBRA NRBQKMABRN RMBNQKNBAR ARBNQKNBRM RQBNKMNBAR BRQNMKNARB RBQNMKNABR NRQBMKBARN NRQBKABMRN RNQBKABMNR NRBAQKMBRN BRQNKANMRB BRANQKNMRB RBANQKNMBR BRNAQKMNRB RBNAQKMNBR MRBNQKNBRA QRBNKMNBRA RQBNKANBMR BRMNQKNARB RBMNQKNABR QRBNKANBRM NRBQKAMBRN NRQBAKBMRN BRNQKAMNRB RBNQKAMNBR RNQBAKBMNR BRQNAKNMRB RBQNAKNMBR NRBQMKABRN NRQBKMBARN BRQNKMNARB BRNQMKANRB RBNQMKANBR