But there are only 5 captures.flok wrote:tomitank wrote:100 - 975 + 325 - 325 + 325 = 550Please do because I can't figure it out.AlvaroBegue wrote:No, that's not it at all. It's -550. I can break it down if you can't figure it out. But don't start with the material value of the queen, because the pawn is the first thing to go.
First of all: why an odd number of additions? there are 6 pieces?
Let's imagine the sequence of moves if everyone captures everything till the end (although they don't have to: Either player could stop and take the "stand pat" score, like in quiescence search).
qxP, Nxq, nxN, Nxn, nxN
Let's write down the sequence of captured piece values, with sign:
+100, -975, +325, -325, +325
Now compute the partial sums (material balance at each step):
+100, -875, -550, -875, -550
Now start at the penultimate place in the list (the second -875) and think of whether the player to move would prefer the material balance at that time (the number we are looking at) or the result of the recapture (the next element in the list).
+100, -875, -550, >>-875<<, -550
In this case it was black's turn, and black would rather see -550 than -875, because in the convention of signs we are using in this post, higher means better for black. So we replace the -875 with -550 and we move back.
+100, -875, >>-550<<, -550, -550
White is indifferent as to whether to pick the -550 from not standing pat or the -550 from recapturing.
+100, >>-875<<, -550, -550, -550
It's black's turn, so black would rather take the -550 from recapturing.
>>+100<<, -550, -550, -550, -550
It's white's turn, so -550 is better than +100.
-550, -550, -550, -550, -550
The result of SEE is the first number, so -550.
