I have been studying chess with the (excellent) book: The right way to play chess by David Pritchard. In the end of chapter 1 there are some exercises and I got a different answer from the book. The postion it is as below:
lichess.org/editor/r3k2r/pp5p/1P1Bn1p1/2pP4/1R6/1n3P2/P2p1KPP/1R3B2_w_kq_-_0_1r3k2r/pp5p/1P1Bn1p1/2pP4/1R6/1n3P2/P2p1KPP/1R3B2 w kq - 0 1
and the exercise is the question 6.
On the whole board, how many possible (i.e. legal) black moves are there? (count the pawn promotion as one move).
The book's answer is 29.
Do you agree? because I have a different one.
yup, 29, assuming you can still castle both ways.
Just a quick glance, 29.
@BurpinBishop But the white bishop at D6 is blocking the castle both sides. So I don't count those as a moves.
...0-0-0 is perfectly legal provided K+R had not moved before.
I got 32 Right now,
-2 of h pawn
-2 of h rook
-1 of g pawn
-7 of e knight
-4 of king (Counting castling)
-2 of c pawn
-0 of b pawn
-3 of a pawn
-3 of a rook
-4 of b knight
-4 different pawn promotions
2+2+1+7+4+2+0+3+3+4+4=5+7+6+6+4+4=12+20=32
@Pablo-No I use the same method for counting them. But why 4 different pawn promotions? I think the pawn of D2 only have one move and therefore one way of promotion: d2-d1.
Edit: now I see the question On the whole board, how many possible (i.e. legal) black moves are there? (count the pawn promotion as one move).
The book's answer is 29.
So 32-3 redundant moves is 29, the book is fine, what's the problem?
Hey Sirs! I just notice thanks to all of you that I was missing the 0-0-0 castling. So now I agree with the answer of the book...hehe. Thank you. I'm completely sure because I count them in the Lichess analysis border. See you.
P.S.
It's kind of frustrating have to do a check mate every forum post. xd
Interesting, I got 30 assuming 0-0-0 is possible. If 0-0-0 is not possible then it's 29. 0-0 is illegal because it's castling through check. 0-0-0 is legal unless the black king or rook has moved prior, so that information must be given for the problem to be fair.
