4 ms·

So judging from the omission of the bishop and the queen, the computer really hated calculating diagonals, huh? I would've assumed that calculating the knight's

So judging from the omission of the bishop and the queen, the computer really hated calculating diagonals, huh? I would've assumed that calculating the knight's movements would've been the bigger headache.

InitialLastName 3y ago
The queen is there. It was probably a more interesting game to keep the knights for their moveset rather than keep the bishops (given the need to reduce to 6x6). Between the ~half-sized board, the intrinsic limitations in where they can go, and the reduced pawn movement, bishops would be very clumsy if left in.
Sharlin 3y ago
I don’t think there’s anything difficult in calculating a knight’s moves. On the other hand rooks, bishops, and queens generate many moves at a time, making the game tree much wider, which might make a difference, or it might not. But anyway, as noted by the sibling, queens were there (except in the second game, in which Kruskal played without and the computer played with, to even the odds), and the omission of bishops in particular had nothing to do with evaluation difficulty per se.
- Sesse__ 3y ago
  Humans are probably worse with knights than any other piece, relative to computers. Queen is a possible second; queen endgames are super-complex for humans since there are so many options and very few of them can be easily pruned. (I guess you can say that humans are bad with knights and computers are good with queens, especially endgame queens.) Diagonal sliders do create lots of headaches for bitboards, but those were not used for chess before 1967 or so, i.e., more than a decade later. Generally one uses magic bitboards today (basically a perfect hashing technique to extract the bits of the diagonals a piece can attack into a neat little linear bit line), but they depend on fast multiplier and a fair amount of RAM for LUTs, which would of course not have been available on the MANIAC. I would assume that MANIAC just looped over all possible moves in the move generation phase.
  - Sharlin 3y ago
    Thanks, interesting!
silisili 3y ago
They retained the queen, it was just the human played without one against the computer for some reason. Probably to give MANIAC a fighting chance.

InitialLastName 3y ago

The queen is there. It was probably a more interesting game to keep the knights for their moveset rather than keep the bishops (given the need to reduce to 6x6). Between the ~half-sized board, the intrinsic limitations in where they can go, and the reduced pawn movement, bishops would be very clumsy if left in.

Sharlin 3y ago

I don’t think there’s anything difficult in calculating a knight’s moves. On the other hand rooks, bishops, and queens generate many moves at a time, making the game tree much wider, which might make a difference, or it might not. But anyway, as noted by the sibling, queens were there (except in the second game, in which Kruskal played without and the computer played with, to even the odds), and the omission of bishops in particular had nothing to do with evaluation difficulty per se.

Sesse__ 3y ago
Humans are probably worse with knights than any other piece, relative to computers. Queen is a possible second; queen endgames are super-complex for humans since there are so many options and very few of them can be easily pruned. (I guess you can say that humans are bad with knights and computers are good with queens, especially endgame queens.) Diagonal sliders do create lots of headaches for bitboards, but those were not used for chess before 1967 or so, i.e., more than a decade later. Generally one uses magic bitboards today (basically a perfect hashing technique to extract the bits of the diagonals a piece can attack into a neat little linear bit line), but they depend on fast multiplier and a fair amount of RAM for LUTs, which would of course not have been available on the MANIAC. I would assume that MANIAC just looped over all possible moves in the move generation phase.
- Sharlin 3y ago
  Thanks, interesting!

silisili 3y ago

They retained the queen, it was just the human played without one against the computer for some reason. Probably to give MANIAC a fighting chance.