Kevin Pacey wrote on Thu, Feb 18, 2016 09:42 PM UTC:
H.G. wrote:
K.Pacey> in Raumschach there are possible mating positions with a K & B plus R
"How do you envisage that? Even in a corner the bare King can only be limited to a plane, and the other pieces would have to cover 4 squares in that plane (including the one the bare King is on). A Bishop could check and cover one of those at the same time, but the only way for a Rook to cover the other two would put it in a place that blocks the Bishop from checking.
I think you need at least two Rooks to have a mate position. And I am not sure that is forcible."
Hi H.G.
I imagined the lone K in a corner on the upper level. The superior side's K would be in opposition to it on the same file (say), same level. The superior side's B would be on the square between them on the same file, same level. The superior side's R (the mating piece) would be on the same corner square as the lone king, except one level below it. The R would be protected by the B. Thus, aside from the superior side's K guarding 4 critical squares, the B guards 2 critical squares (including one on the upper level), and the R guards 2 critical squares (including one on the level below the Ks). That's if I've visualized this all correctly.