As part of solving IBM September Ponder this challenge https://researchweb.watson.ibm.com/haifa/ponderthis/challenges/September2017.html
The 960 different Fischer variations of the initial chess board positions using FEN Notation (https://en.wikipedia.org/wiki/Forsyth–Edwards_Notation)
BBNNQRKR
BBNNRKQR
BBNNRKRQ
BBNNRQKR
BBNQNRKR
BBNQRKNR
BBNQRKRN
BBNQRNKR
BBNRKNQR
BBNRKNRQ
BBNRKQNR
BBNRKQRN
BBNRKRNQ
BBNRKRQN
BBNRNKQR
BBNRNKRQ
BBNRNQKR
BBNRQKNR
BBNRQKRN
BBNRQNKR
BBQNNRKR
BBQNRKNR
BBQNRKRN
BBQNRNKR
BBQRKNNR
BBQRKNRN
BBQRKRNN
BBQRNKNR
BBQRNKRN
BBQRNNKR
BBRKNNQR
BBRKNNRQ
BBRKNQNR
BBRKNQRN
BBRKNRNQ
BBRKNRQN
BBRKQNNR
BBRKQNRN
BBRKQRNN
BBRKRNNQ
BBRKRNQN
BBRKRQNN
BBRNKNQR
BBRNKNRQ
BBRNKQNR
BBRNKQRN
BBRNKRNQ
BBRNKRQN
BBRNNKQR
BBRNNKRQ
BBRNNQKR
BBRNQKNR
BBRNQKRN
BBRNQNKR
BBRQKNNR
BBRQKNRN
BBRQKRNN
BBRQNKNR
BBRQNKRN
BBRQNNKR
BNNBQRKR
BNNBRKQR
BNNBRKRQ
BNNBRQKR
BNNQRBKR
BNNQRKRB
BNNRKBQR
BNNRKBRQ
BNNRKQRB
BNNRKRQB
BNNRQBKR
BNNRQKRB
BNQBNRKR
BNQBRKNR
BNQBRKRN
BNQBRNKR
BNQNRBKR
BNQNRKRB
BNQRKBNR
BNQRKBRN
BNQRKNRB
BNQRKRNB
BNQRNBKR
BNQRNKRB
BNRBKNQR
BNRBKNRQ
BNRBKQNR
BNRBKQRN
BNRBKRNQ
BNRBKRQN
BNRBNKQR
BNRBNKRQ
BNRBNQKR
BNRBQKNR
BNRBQKRN
BNRBQNKR
BNRKNBQR
BNRKNBRQ
BNRKNQRB
BNRKNRQB
BNRKQBNR
BNRKQBRN
BNRKQNRB
BNRKQRNB
BNRKRBNQ
BNRKRBQN
BNRKRNQB
BNRKRQNB
BNRNKBQR
BNRNKBRQ
BNRNKQRB
BNRNKRQB
BNRNQBKR
BNRNQKRB
BNRQKBNR
BNRQKBRN
BNRQKNRB
BNRQKRNB
BNRQNBKR
BNRQNKRB
BQNBNRKR
BQNBRKNR
BQNBRKRN
BQNBRNKR
BQNNRBKR
BQNNRKRB
BQNRKBNR
BQNRKBRN
BQNRKNRB
BQNRKRNB
BQNRNBKR
BQNRNKRB
BQRBKNNR
BQRBKNRN
BQRBKRNN
BQRBNKNR
BQRBNKRN
BQRBNNKR
BQRKNBNR
BQRKNBRN
BQRKNNRB
BQRKNRNB
BQRKRBNN
BQRKRNNB
BQRNKBNR
BQRNKBRN
BQRNKNRB
BQRNKRNB
BQRNNBKR
BQRNNKRB
BRKBNNQR
BRKBNNRQ
BRKBNQNR
BRKBNQRN
BRKBNRNQ
BRKBNRQN
BRKBQNNR
BRKBQNRN
BRKBQRNN
BRKBRNNQ
BRKBRNQN
BRKBRQNN
BRKNNBQR
BRKNNBRQ
BRKNNQRB
BRKNNRQB
BRKNQBNR
BRKNQBRN
BRKNQNRB
BRKNQRNB
BRKNRBNQ
BRKNRBQN
BRKNRNQB
BRKNRQNB
BRKQNBNR
BRKQNBRN
BRKQNNRB
BRKQNRNB
BRKQRBNN
BRKQRNNB
BRKRNBNQ
BRKRNBQN
BRKRNNQB
BRKRNQNB
BRKRQBNN
BRKRQNNB
BRNBKNQR
BRNBKNRQ
BRNBKQNR
BRNBKQRN
BRNBKRNQ
BRNBKRQN
BRNBNKQR
BRNBNKRQ
BRNBNQKR
BRNBQKNR
BRNBQKRN
BRNBQNKR
BRNKNBQR
BRNKNBRQ
BRNKNQRB
BRNKNRQB
BRNKQBNR
BRNKQBRN
BRNKQNRB
BRNKQRNB
BRNKRBNQ
BRNKRBQN
BRNKRNQB
BRNKRQNB
BRNNKBQR
BRNNKBRQ
BRNNKQRB
BRNNKRQB
BRNNQBKR
BRNNQKRB
BRNQKBNR
BRNQKBRN
BRNQKNRB
BRNQKRNB
BRNQNBKR
BRNQNKRB
BRQBKNNR
BRQBKNRN
BRQBKRNN
BRQBNKNR
BRQBNKRN
BRQBNNKR
BRQKNBNR
BRQKNBRN
BRQKNNRB
BRQKNRNB
BRQKRBNN
BRQKRNNB
BRQNKBNR
BRQNKBRN
BRQNKNRB
BRQNKRNB
BRQNNBKR
BRQNNKRB
NBBNQRKR
NBBNRKQR
NBBNRKRQ
NBBNRQKR
NBBQNRKR
NBBQRKNR
NBBQRKRN
NBBQRNKR
NBBRKNQR
NBBRKNRQ
NBBRKQNR
NBBRKQRN
NBBRKRNQ
NBBRKRQN
NBBRNKQR
NBBRNKRQ
NBBRNQKR
NBBRQKNR
NBBRQKRN
NBBRQNKR
NBNQBRKR
NBNQRKBR
NBNRBKQR
NBNRBKRQ
NBNRBQKR
NBNRKQBR
NBNRKRBQ
NBNRQKBR
NBQNBRKR
NBQNRKBR
NBQRBKNR
NBQRBKRN
NBQRBNKR
NBQRKNBR
NBQRKRBN
NBQRNKBR
NBRKBNQR
NBRKBNRQ
NBRKBQNR
NBRKBQRN
NBRKBRNQ
NBRKBRQN
NBRKNQBR
NBRKNRBQ
NBRKQNBR
NBRKQRBN
NBRKRNBQ
NBRKRQBN
NBRNBKQR
NBRNBKRQ
NBRNBQKR
NBRNKQBR
NBRNKRBQ
NBRNQKBR
NBRQBKNR
NBRQBKRN
NBRQBNKR
NBRQKNBR
NBRQKRBN
NBRQNKBR
NNBBQRKR
NNBBRKQR
NNBBRKRQ
NNBBRQKR
NNBQRBKR
NNBQRKRB
NNBRKBQR
NNBRKBRQ
NNBRKQRB
NNBRKRQB
NNBRQBKR
NNBRQKRB
NNQBBRKR
NNQBRKBR
NNQRBBKR
NNQRBKRB
NNQRKBBR
NNQRKRBB
NNRBBKQR
NNRBBKRQ
NNRBBQKR
NNRBKQBR
NNRBKRBQ
NNRBQKBR
NNRKBBQR
NNRKBBRQ
NNRKBQRB
NNRKBRQB
NNRKQBBR
NNRKQRBB
NNRKRBBQ
NNRKRQBB
NNRQBBKR
NNRQBKRB
NNRQKBBR
NNRQKRBB
NQBBNRKR
NQBBRKNR
NQBBRKRN
NQBBRNKR
NQBNRBKR
NQBNRKRB
NQBRKBNR
NQBRKBRN
NQBRKNRB
NQBRKRNB
NQBRNBKR
NQBRNKRB
NQNBBRKR
NQNBRKBR
NQNRBBKR
NQNRBKRB
NQNRKBBR
NQNRKRBB
NQRBBKNR
NQRBBKRN
NQRBBNKR
NQRBKNBR
NQRBKRBN
NQRBNKBR
NQRKBBNR
NQRKBBRN
NQRKBNRB
NQRKBRNB
NQRKNBBR
NQRKNRBB
NQRKRBBN
NQRKRNBB
NQRNBBKR
NQRNBKRB
NQRNKBBR
NQRNKRBB
NRBBKNQR
NRBBKNRQ
NRBBKQNR
NRBBKQRN
NRBBKRNQ
NRBBKRQN
NRBBNKQR
NRBBNKRQ
NRBBNQKR
NRBBQKNR
NRBBQKRN
NRBBQNKR
NRBKNBQR
NRBKNBRQ
NRBKNQRB
NRBKNRQB
NRBKQBNR
NRBKQBRN
NRBKQNRB
NRBKQRNB
NRBKRBNQ
NRBKRBQN
NRBKRNQB
NRBKRQNB
NRBNKBQR
NRBNKBRQ
NRBNKQRB
NRBNKRQB
NRBNQBKR
NRBNQKRB
NRBQKBNR
NRBQKBRN
NRBQKNRB
NRBQKRNB
NRBQNBKR
NRBQNKRB
NRKBBNQR
NRKBBNRQ
NRKBBQNR
NRKBBQRN
NRKBBRNQ
NRKBBRQN
NRKBNQBR
NRKBNRBQ
NRKBQNBR
NRKBQRBN
NRKBRNBQ
NRKBRQBN
NRKNBBQR
NRKNBBRQ
NRKNBQRB
NRKNBRQB
NRKNQBBR
NRKNQRBB
NRKNRBBQ
NRKNRQBB
NRKQBBNR
NRKQBBRN
NRKQBNRB
NRKQBRNB
NRKQNBBR
NRKQNRBB
NRKQRBBN
NRKQRNBB
NRKRBBNQ
NRKRBBQN
NRKRBNQB
NRKRBQNB
NRKRNBBQ
NRKRNQBB
NRKRQBBN
NRKRQNBB
NRNBBKQR
NRNBBKRQ
NRNBBQKR
NRNBKQBR
NRNBKRBQ
NRNBQKBR
NRNKBBQR
NRNKBBRQ
NRNKBQRB
NRNKBRQB
NRNKQBBR
NRNKQRBB
NRNKRBBQ
NRNKRQBB
NRNQBBKR
NRNQBKRB
NRNQKBBR
NRNQKRBB
NRQBBKNR
NRQBBKRN
NRQBBNKR
NRQBKNBR
NRQBKRBN
NRQBNKBR
NRQKBBNR
NRQKBBRN
NRQKBNRB
NRQKBRNB
NRQKNBBR
NRQKNRBB
NRQKRBBN
NRQKRNBB
NRQNBBKR
NRQNBKRB
NRQNKBBR
NRQNKRBB
QBBNNRKR
QBBNRKNR
QBBNRKRN
QBBNRNKR
QBBRKNNR
QBBRKNRN
QBBRKRNN
QBBRNKNR
QBBRNKRN
QBBRNNKR
QBNNBRKR
QBNNRKBR
QBNRBKNR
QBNRBKRN
QBNRBNKR
QBNRKNBR
QBNRKRBN
QBNRNKBR
QBRKBNNR
QBRKBNRN
QBRKBRNN
QBRKNNBR
QBRKNRBN
QBRKRNBN
QBRNBKNR
QBRNBKRN
QBRNBNKR
QBRNKNBR
QBRNKRBN
QBRNNKBR
QNBBNRKR
QNBBRKNR
QNBBRKRN
QNBBRNKR
QNBNRBKR
QNBNRKRB
QNBRKBNR
QNBRKBRN
QNBRKNRB
QNBRKRNB
QNBRNBKR
QNBRNKRB
QNNBBRKR
QNNBRKBR
QNNRBBKR
QNNRBKRB
QNNRKBBR
QNNRKRBB
QNRBBKNR
QNRBBKRN
QNRBBNKR
QNRBKNBR
QNRBKRBN
QNRBNKBR
QNRKBBNR
QNRKBBRN
QNRKBNRB
QNRKBRNB
QNRKNBBR
QNRKNRBB
QNRKRBBN
QNRKRNBB
QNRNBBKR
QNRNBKRB
QNRNKBBR
QNRNKRBB
QRBBKNNR
QRBBKNRN
QRBBKRNN
QRBBNKNR
QRBBNKRN
QRBBNNKR
QRBKNBNR
QRBKNBRN
QRBKNNRB
QRBKNRNB
QRBKRBNN
QRBKRNNB
QRBNKBNR
QRBNKBRN
QRBNKNRB
QRBNKRNB
QRBNNBKR
QRBNNKRB
QRKBBNNR
QRKBBNRN
QRKBBRNN
QRKBNNBR
QRKBNRBN
QRKBRNBN
QRKNBBNR
QRKNBBRN
QRKNBNRB
QRKNBRNB
QRKNNBBR
QRKNNRBB
QRKNRBBN
QRKNRNBB
QRKRBBNN
QRKRBNNB
QRKRNBBN
QRKRNNBB
QRNBBKNR
QRNBBKRN
QRNBBNKR
QRNBKNBR
QRNBKRBN
QRNBNKBR
QRNKBBNR
QRNKBBRN
QRNKBNRB
QRNKBRNB
QRNKNBBR
QRNKNRBB
QRNKRBBN
QRNKRNBB
QRNNBBKR
QRNNBKRB
QRNNKBBR
QRNNKRBB
RBBKNNQR
RBBKNNRQ
RBBKNQNR
RBBKNQRN
RBBKNRNQ
RBBKNRQN
RBBKQNNR
RBBKQNRN
RBBKQRNN
RBBKRNNQ
RBBKRNQN
RBBKRQNN
RBBNKNQR
RBBNKNRQ
RBBNKQNR
RBBNKQRN
RBBNKRNQ
RBBNKRQN
RBBNNKQR
RBBNNKRQ
RBBNNQKR
RBBNQKNR
RBBNQKRN
RBBNQNKR
RBBQKNNR
RBBQKNRN
RBBQKRNN
RBBQNKNR
RBBQNKRN
RBBQNNKR
RBKNBNQR
RBKNBNRQ
RBKNBQNR
RBKNBQRN
RBKNBRNQ
RBKNBRQN
RBKNNQBR
RBKNNRBQ
RBKNQNBR
RBKNQRBN
RBKNRNBQ
RBKNRQBN
RBKQBNNR
RBKQBNRN
RBKQBRNN
RBKQNNBR
RBKQNRBN
RBKQRNBN
RBKRBNNQ
RBKRBNQN
RBKRBQNN
RBKRNNBQ
RBKRNQBN
RBKRQNBN
RBNKBNQR
RBNKBNRQ
RBNKBQNR
RBNKBQRN
RBNKBRNQ
RBNKBRQN
RBNKNQBR
RBNKNRBQ
RBNKQNBR
RBNKQRBN
RBNKRNBQ
RBNKRQBN
RBNNBKQR
RBNNBKRQ
RBNNBQKR
RBNNKQBR
RBNNKRBQ
RBNNQKBR
RBNQBKNR
RBNQBKRN
RBNQBNKR
RBNQKNBR
RBNQKRBN
RBNQNKBR
RBQKBNNR
RBQKBNRN
RBQKBRNN
RBQKNNBR
RBQKNRBN
RBQKRNBN
RBQNBKNR
RBQNBKRN
RBQNBNKR
RBQNKNBR
RBQNKRBN
RBQNNKBR
RKBBNNQR
RKBBNNRQ
RKBBNQNR
RKBBNQRN
RKBBNRNQ
RKBBNRQN
RKBBQNNR
RKBBQNRN
RKBBQRNN
RKBBRNNQ
RKBBRNQN
RKBBRQNN
RKBNNBQR
RKBNNBRQ
RKBNNQRB
RKBNNRQB
RKBNQBNR
RKBNQBRN
RKBNQNRB
RKBNQRNB
RKBNRBNQ
RKBNRBQN
RKBNRNQB
RKBNRQNB
RKBQNBNR
RKBQNBRN
RKBQNNRB
RKBQNRNB
RKBQRBNN
RKBQRNNB
RKBRNBNQ
RKBRNBQN
RKBRNNQB
RKBRNQNB
RKBRQBNN
RKBRQNNB
RKNBBNQR
RKNBBNRQ
RKNBBQNR
RKNBBQRN
RKNBBRNQ
RKNBBRQN
RKNBNQBR
RKNBNRBQ
RKNBQNBR
RKNBQRBN
RKNBRNBQ
RKNBRQBN
RKNNBBQR
RKNNBBRQ
RKNNBQRB
RKNNBRQB
RKNNQBBR
RKNNQRBB
RKNNRBBQ
RKNNRQBB
RKNQBBNR
RKNQBBRN
RKNQBNRB
RKNQBRNB
RKNQNBBR
RKNQNRBB
RKNQRBBN
RKNQRNBB
RKNRBBNQ
RKNRBBQN
RKNRBNQB
RKNRBQNB
RKNRNBBQ
RKNRNQBB
RKNRQBBN
RKNRQNBB
RKQBBNNR
RKQBBNRN
RKQBBRNN
RKQBNNBR
RKQBNRBN
RKQBRNBN
RKQNBBNR
RKQNBBRN
RKQNBNRB
RKQNBRNB
RKQNNBBR
RKQNNRBB
RKQNRBBN
RKQNRNBB
RKQRBBNN
RKQRBNNB
RKQRNBBN
RKQRNNBB
RKRBBNNQ
RKRBBNQN
RKRBBQNN
RKRBNNBQ
RKRBNQBN
RKRBQNBN
RKRNBBNQ
RKRNBBQN
RKRNBNQB
RKRNBQNB
RKRNNBBQ
RKRNNQBB
RKRNQBBN
RKRNQNBB
RKRQBBNN
RKRQBNNB
RKRQNBBN
RKRQNNBB
RNBBKNQR
RNBBKNRQ
RNBBKQNR
RNBBKQRN
RNBBKRNQ
RNBBKRQN
RNBBNKQR
RNBBNKRQ
RNBBNQKR
RNBBQKNR
RNBBQKRN
RNBBQNKR
RNBKNBQR
RNBKNBRQ
RNBKNQRB
RNBKNRQB
RNBKQBNR
RNBKQBRN
RNBKQNRB
RNBKQRNB
RNBKRBNQ
RNBKRBQN
RNBKRNQB
RNBKRQNB
RNBNKBQR
RNBNKBRQ
RNBNKQRB
RNBNKRQB
RNBNQBKR
RNBNQKRB
RNBQKBNR
RNBQKBRN
RNBQKNRB
RNBQKRNB
RNBQNBKR
RNBQNKRB
RNKBBNQR
RNKBBNRQ
RNKBBQNR
RNKBBQRN
RNKBBRNQ
RNKBBRQN
RNKBNQBR
RNKBNRBQ
RNKBQNBR
RNKBQRBN
RNKBRNBQ
RNKBRQBN
RNKNBBQR
RNKNBBRQ
RNKNBQRB
RNKNBRQB
RNKNQBBR
RNKNQRBB
RNKNRBBQ
RNKNRQBB
RNKQBBNR
RNKQBBRN
RNKQBNRB
RNKQBRNB
RNKQNBBR
RNKQNRBB
RNKQRBBN
RNKQRNBB
RNKRBBNQ
RNKRBBQN
RNKRBNQB
RNKRBQNB
RNKRNBBQ
RNKRNQBB
RNKRQBBN
RNKRQNBB
RNNBBKQR
RNNBBKRQ
RNNBBQKR
RNNBKQBR
RNNBKRBQ
RNNBQKBR
RNNKBBQR
RNNKBBRQ
RNNKBQRB
RNNKBRQB
RNNKQBBR
RNNKQRBB
RNNKRBBQ
RNNKRQBB
RNNQBBKR
RNNQBKRB
RNNQKBBR
RNNQKRBB
RNQBBKNR
RNQBBKRN
RNQBBNKR
RNQBKNBR
RNQBKRBN
RNQBNKBR
RNQKBBNR
RNQKBBRN
RNQKBNRB
RNQKBRNB
RNQKNBBR
RNQKNRBB
RNQKRBBN
RNQKRNBB
RNQNBBKR
RNQNBKRB
RNQNKBBR
RNQNKRBB
RQBBKNNR
RQBBKNRN
RQBBKRNN
RQBBNKNR
RQBBNKRN
RQBBNNKR
RQBKNBNR
RQBKNBRN
RQBKNNRB
RQBKNRNB
RQBKRBNN
RQBKRNNB
RQBNKBNR
RQBNKBRN
RQBNKNRB
RQBNKRNB
RQBNNBKR
RQBNNKRB
RQKBBNNR
RQKBBNRN
RQKBBRNN
RQKBNNBR
RQKBNRBN
RQKBRNBN
RQKNBBNR
RQKNBBRN
RQKNBNRB
RQKNBRNB
RQKNNBBR
RQKNNRBB
RQKNRBBN
RQKNRNBB
RQKRBBNN
RQKRBNNB
RQKRNBBN
RQKRNNBB
RQNBBKNR
RQNBBKRN
RQNBBNKR
RQNBKNBR
RQNBKRBN
RQNBNKBR
RQNKBBNR
RQNKBBRN
RQNKBNRB
RQNKBRNB
RQNKNBBR
RQNKNRBB
RQNKRBBN
RQNKRNBB
RQNNBBKR
RQNNBKRB
RQNNKBBR
RQNNKRBB