I have trouble understanding null move pruning. I understand the concept of a free move for the side that just played a move, but what I don't understand is the code part:

int score = -negamax(-beta,-beta+1,depht-1-R)

Why do we pass in for the second parameter -beta + 1, why not -alpha?

  • This looks to me like a coding question rather than a chess one
    – David
    Oct 25, 2021 at 21:48
  • 1
    I thought coding questions were allowed. Oct 26, 2021 at 8:52
  • They are, but few people will know the answer
    – David
    Oct 26, 2021 at 9:34
  • Well do you understand PVS/Negascout? The principle of the null window is same. Nov 10, 2021 at 15:26
  • Haven't looked at PVS or Negascout. Nov 11, 2021 at 16:48


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