Sharper, a Chess Engine Communication Protocol aka Winboard compliant chess engine by Albert Bertilsson, written in C++. Sharper emerged in 2002 and 2003 from Albert's former engine #Chess, which was written in C# [1]. Released in 2003 [2], Sharper became a reference engine for Perft and Divide results.
Card-Sharpers [3]

Features

Board Representation

• 0x88
• Piece-Lists
• Bitboards

Search

• Iterative Deepening
  Aspiration Windows
• Alpha-Beta
• Transposition Table
  Zobrist Hashing
• Quiescence Search
• Verified Null Move Pruning
• Fractional Extensions
  Check Extensions
  One Reply Extensions
  Pawns to 7th Rank
  Promotions
• Move Ordering
  MVV/LVA
  History Heuristic
  Piece-Square Tables

Evaluation

• Material
  Bishop Pair
• Piece-Square Tables ^[5]
• King Safety
• Pawn Structure
  Pawn Hash Table

Misc

• Opening Book
• Perft and Divide
• Pondering

See also

• #Chess
• SharpChess by Peter Hughes

Forum Posts

2003

February ...

• To Uri, about perft speeds by Albert Bertilsson, Winboard Forum, February 14, 2003 » Perft
• Perft 9, confirmed by Sharper too... by Albert Bertilsson, Winboard Forum, February 16, 2003
• Why have a UnMakeMove or UndoMove function (not as stupid as it sounds)? by Albert Bertilsson, CCC, February 24, 2003 » Unmake Move
• New engine, Sharper 0.02! by Albert Bertilsson, Winboard Forum, March 09, 2003
• Sharper version 0.03 released! by Albert Bertilsson, Winboard Forum, March 12, 2003
• Adding knowledge to the evaluation, what am I doing wrong? by Albert Bertilsson, CCC, March 13, 2003
• WACNEW 40% less fails when Sharper get 12x the time by Albert Bertilsson, CCC, March 17, 2003 » Win at Chess
• What's best low BF or good WAC result? by Albert Bertilsson, CCC, March 18, 2003 » Branching Factor
• Buggy check extensions, back to square one =(. by Albert Bertilsson, CCC, March 20, 2003 » Check Extensions
• Sharper 0.04 released by Albert Bertilsson, Winboard Forum, March 22, 2003
• I search for an opening book for my engine... by Albert Bertilsson, CCC, March 26, 2003

April ...

• Sharper 0.06 released! by Albert Bertilsson, Winboard Forum, April 04, 2003
• My engine doesn't understand this position neither do I by Albert Bertilsson, CCC, April 25, 2003
• Sharper 0.07 by Albert Bertilsson, Winboard Forum, April 26, 2003
• Dual processor owners, please help me with 15 min of CPU time by Albert Bertilsson, CCC, May 23, 2003

June ...

• Sharper 0.10 released by Albert Bertilsson, Winboard Forum, June 25, 2003
• Problem with extending to maxdepth by Albert Bertilsson, CCC, June 26, 2003 » Extensions
• Improvements in BF makes my MoveGen suck =( by Albert Bertilsson, CCC, June 26, 2003 » Branching Factor, Move Generation
• Program settings (Re: Programmers Should Take A Cue From Chessmaster) by Albert Bertilsson, CCC, July 04, 2003 » Piece-Square Tables
• How stable is stable enough for you? by Albert Bertilsson, CCC, July 24, 2003
• Sharper 0.11 released by Albert Bertilsson, Winboard Forum, July 27, 2003
• Sharper 0.12 released by Albert Bertilsson, Winboard Forum, July 31, 2003

August ...

• Sharper 0.14 released! by Albert Bertilsson, Winboard Forum, August 03, 2003
• Sharper version 0.16 released by Albert Bertilsson, Winboard Forum, October 22, 2003
• Highest perft for initial position? by Albert Bertilsson, CCC, November 07, 2003 » Perft
• Anybody interested in a new version of Sharper? by Albert Bertilsson, Winboard Forum, November 24, 2003
• Sharper 0.17 released by Albert Bertilsson, Winboard Forum, November 27, 2003
• A few Sharper pertfhash 8 benchmarks by Frederic Louguet, CCC, December 18, 2003

2004

• Newer version of Sharper is available by Albert Bertilsson, Winboard Forum, January 11, 2004
• Improving the endgame of my engine by Albert Bertilsson, CCC, April 08, 2004 » Endgame

2010 ...

• perft/divide bug in roce38 and Sharper? [SOLVED] by thedrunkard, Winboard Forum, October 16, 2013 » Perft, ROCE

External Links

Chess Engine

• Sharper (Wayback Machine)
• Sharper 0.17 in CCRL 40/4

Misc

• Sharper from Wikipedia
• sharper - Wiktionary
• Sharp from Wikipedia

References

1. ^ #Chess (Wayback Machine)
2. ^ New engine, Sharper 0.02! by Albert Bertilsson, Winboard Forum, March 09, 2003
3. ^ Card-sharpers by candlelight by Feliks Pęczarski, oil on canvas, 1845, Current location: National Museum, Warsaw, Wikimedia Commons, Card sharp from Wikipedia
4. ^ Features based on History.txt, November 2003
5. ^ Program settings (Re: Programmers Should Take A Cue From Chessmaster) by Albert Bertilsson, CCC, July 04, 2003

What links here?