Knight and Bishop Checkmate on a Large Board

The bishop and knight checkmate against a lone king occurs extremely rarely in normal chess games.  (I have never encountered it.)  But I see it as an interesting case study on the abilities of the pieces.  Are the knight, bishop, and king strong enough to corral the opposing king into the corner?  Indeed they are, and the crux of the most common method is a procedure called a “W-maneuver”.

Playing through the W-maneuver has a very tenuous feel to it, with the defending king on the brink of escape at one point.  This makes me want to kick its tires a little, to see if the bishop and knight checkmate is “almost impossible”.  One way to do this is to see if the mate can be forced on a larger board, say 10×10.  What about 100×100?  Someone asked exactly this question on chess.stackexchange, and I used an endgame tablebase program I wrote to answer it.

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