syd-format

format used to store a whole chess tree, heavily inspired by viriformat

specifications

for each tree:

• 4B: store the size of tree as u32
• 32B: store the root as marlin format
• recursively :
  • 2B: the bestmove
  • 2B: the score of the position
  • 1B: depth*3+bound
  • 1B: the number of child
  • for each child :
    • 2B: store the move to go to that child
    • store the child

so the root is 42B, and every other node is 8B

moves

a Move is stored into 2 bytes :

• 6-bit from square
• 6-bit to square
• 2-bit promotion type (normal piece number - 1)
• 2-bit flag, 1 for ep 2 for castling 3 for promotions and 0 for the rest

all integers are stored in little endian

all scores are stored stm-relative as i16