Verified Null-Move Pruning
Abstract
In this article we review standard null-move pruning and introduce our extended version of it, which we call verified null-move pruning. In verified null-move pruning, whenever the shallow null-move search indicates a fail-high, instead of cutting off the search from the current node, the search is continued with reduced depth. Our experiments with verified null-move pruning show that on average, it constructs a smaller search tree with greater tactical strength in comparison to standard null-move pruning. Moreover, unlike standard null-move pruning, which fails badly in zugzwang positions, verified null-move pruning manages to detect most zugzwangs and in such cases conducts a re-search to obtain the correct result. In addition, verified null-move pruning is very easy to implement, and any standard null-move pruning program can use verified null-move pruning by modifying only a few lines of code.
- Publication:
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arXiv e-prints
- Pub Date:
- August 2008
- DOI:
- 10.48550/arXiv.0808.1125
- arXiv:
- arXiv:0808.1125
- Bibcode:
- 2008arXiv0808.1125D
- Keywords:
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- Computer Science - Artificial Intelligence;
- I.2.8
- E-Print:
- 9 pages