George Duke wrote on Tue, Jan 31, 2012 04:21 PM UTC:
Thanks Jorg, I got to rechecking not sovereign (Quintessence 3.5, 2) but
TABLE OF SOVEREIGN VALUES(II)Venator below. Corrections when several will
P/T P/V Mate# be entried. Sovereign (Venator 3.5/5) would not
CANNON 4.5 3 be surprising Mate# turns out 4 or 6, not 5,
CANNON PAWN 2.2 4 though '5' checks out the second test on paper
QUADRA-PAWN 2.0 3 only. A generality: Mating Number >=3, the
HALF DUCK 4.5 2 set-up position of checkmate is attainable in
NAHBI 5.0 2 practice over the board. However, mating
UNICORN 6.5 1 numbers 2 and 1 tend to need computer veri-
DABBABANTE 5.5 2 fication. A subclass of '1's, (Rook 5.0/1)
SISSA 6.0 1 for one, of course are obvious cases without
WOLF 3.75 2 computer. For example, White Venators c4, d3,
PRIEST 4.25 2 d4, f4, f5, King c2, beat Black King d1.
WATER ROOK 3.0 2 Checkmate. It's important to test the plausible last two or three moves. A last move by White could be Venator g5-d4, delivering the Checkmate. So '5' is probably the right Mate# sovereign (Venator 3.5/5). How can a mating number be '0'? They belong not exclusively to cases of piece-types having negative value; it may have some value but not for check or checkmate, for eventual follow-up.