# Superultra (NNUE)
## Overview
Superultra is a UCI compliant chess engine that uses an alpha-beta search framework, various heuristics and optimization techniques, and an efficiently updatable neural network (NNUE) in order to analyze chess positions and calculate moves.
## Usage
Superultra supports the UCI Protocol but does not come with a GUI (like most UCI chess engines). It is recomended to download a UCI Compatable GUI such as cutechess.
## Features
### Board Representation
* Bitboards
* Magic Bitboards for efficient slider attack generation
### Search
* Iterative Deepening
* Aspiration Windows
* Parallel Search with Lazy SMP
* Principle Variation Search
* Transposition Table with 4 buckets and aging (shared across threads)
* Move Ordering
* Countermove Heuristic
* Killer Heuristic
* Continuation History Heuristic and History Heuristic (with gravity)
* MVV/LVA
* SEE
* Transposition Table Move
* Pruning, Reductions, and Extensions
* Null Move Pruning
* Razoring
* Reverse Futility Pruning
* Probcut
* Quiet Move Pruning
* Move Count Pruning
* Futility Pruning
* History Pruning
* SEE Pruning
* Singular Extensions + Multicut Pruning
* Late Move Reductions
* Quiescence Search
* Time Management
* Best move stability
* Score stability
* Complexity based on the percentage of time spent searching moves that are not the best move
### Evaluation
* Efficiently Updatable Neural Network
* (768x10-->512)x2-->1 architecture
* Perspective
* Crelu Activation Function
* 10 King Buckets (mirrored)
* 8 Output Weight Buckets
