Hi Kevin. The 91-hex board endgame databases that I generated take into account colorbound pieces, including the distinction between "central" and "non-central" colorbound pieces. The results are available on these pages, with a link from this page. For the KNBvK endgame, I use the suffix "(xc)" for the central-B case and "(xn)" for the non-central-B case. The central-B case has a slightly higher winning percentage (0.98% vs 0.25%), but both of these percentages are quite small. Over 99% of all positions in both endgames are drawn.