Windmill (chess)

In chess, a windmill is a tactic in which a combination of discovered checks and regular checks, usually by a rook and a bishop, can win massive amounts of material. This tactic is also sometimes referred to as a see-saw.

Examples

In the game pictured at right,Carlos Torre-Repetto makes use of the windmill tactic against Emanuel Lasker to win two pawns and a bishop and enter into a winning endgame (although the bishop had to be given back). The move 25. Bf6!, hanging the queen, sets up the windmill. Black must accept the sacrifice, as his own queen is unprotected, and any attempt to stop the windmill would simply give White the queen. Then 25. ... Qxh5 26. Rxg7+ Kh8 27. Rxf7+ Discovered check, by the bishop. White simply repeats the regular check/discovered check pattern, taking as many pieces as he can with his rook. 27. ...Kg8 28. Rg7+ Kh8 29. Rxb7+ Kg8 30. Rg7+ Kh8 31. Rg5+ Kh7 32. Rxh5 White concludes the windmill by taking the black queen.

Another example is in Bobby Fischer's Game of the Century, from moves 18 to 23. In this case, the windmill involved a knight and a bishop.

Windmill

A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain, pump water, or both. Thus they often were gristmills, windpumps, or both. The majority of modern windmills take the form of wind turbines used to generate electricity, or windpumps used to pump water, either for land drainage or to extract groundwater.

Windmills in antiquity

The windwheel of the Greek engineer Heron of Alexandria in the first century is the earliest known instance of using a wind-driven wheel to power a machine. Another early example of a wind-driven wheel was the prayer wheel, which has been used in Tibet and China since the fourth century. It has been claimed that the Babylonian emperor Hammurabi planned to use wind power for his ambitious irrigation project in the seventeenth century BCE.

Horizontal windmills

The first practical windmills had sails that rotated in a horizontal plane, around a vertical axis. According to Ahmad Y. al-Hassan, these panemone windmills were invented in eastern Persia as recorded by the Persian geographer Estakhri in the ninth century. The authenticity of an earlier anecdote of a windmill involving the second caliph Umar (AD 634–644) is questioned on the grounds that it appears in a tenth-century document. Made of six to 12 sails covered in reed matting or cloth material, these windmills were used to grind grain or draw up water, and were quite different from the later European vertical windmills. Windmills were in widespread use across the Middle East and Central Asia, and later spread to China and India from there.

Windmill (song)

"Windmill" is a song and a single made by the German power metal band Helloween taken from the album Chameleon. It was released in some countries as Windmill. In Japan, it was released as Step Out of Hell.

Single track listing

Japanese Version

Personnel

References

List of G.I. Joe: A Real American Hero characters (S–Z)

This is an alphabetical List of G.I. Joe: A Real American Hero characters whose code names start with the letters S-Z.

Salvo

Salvo is the G.I. Joe Team's Anti-Armor Trooper. His real name is David K. Hasle, and he was born in Arlington, Virginia. Salvo was first released as an action figure in 1990, and again in 2005. Both versions have the T-shirt slogan 'The Right of Might'.

Salvo's primary military specialty is anti-armor trooper. He also specializes in repairing "TOW/Dragon" missiles. Salvo expresses a deep distrust of advanced electronic weaponry. He prefers to use mass quantities of conventional explosives to overwhelm enemy forces.

In the Marvel Comics G.I. Joe series, he first appeared in issue #114. There, he fights as part of a large scale operation against Cobra forces in the fictional country of Benzheen. Steeler, Dusty, Salvo, Rock'N'Roll and Hot Seat get into vehicular based combat against the missile expert Metal-Head He is later part of the Joe team on-site who defends G.I. Joe headquarters in Utah against a Cobra assault.

Chess

Chess is a two-player board game played on a chessboard, a checkered gameboard with 64 squares arranged in an eight-by-eight grid. Chess is played by millions of people worldwide, both amateurs and professionals.

Each player begins the game with 16 pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. Each of the six piece types moves differently. The most powerful piece is the queen and the least powerful piece is the pawn. The objective is to 'checkmate' the opponent's king by placing it under an inescapable threat of capture. To this end, a player's pieces are used to attack and capture the opponent's pieces, while supporting their own. In addition to checkmate, the game can be won by voluntary resignation by the opponent, which typically occurs when too much material is lost, or if checkmate appears unavoidable. A game may also result in a draw in several ways.

Chess is believed to have originated in India, some time before the 7th century; the Indian game of chaturanga is also the likely ancestor of xiangqi and shogi. The pieces took on their current powers in Spain in the late 15th century; the rules were finally standardized in the 19th century.

Chess annotation symbols

When annotating chess games, commentators frequently use widely recognized annotation symbols. Question marks and exclamation points that denote a move as bad or good are ubiquitous in chess literature. Some publications intended for an international audience, such as the Chess Informant have a wide range of additional symbols that transcend language barriers.

The common symbols for evaluating the merits of a move are "??", "?", "?!", "!?", "!", and "!!". In these cases, the corresponding symbol is juxtaposed in the text immediately after the move (e.g. Re7? or Kh1!?, see algebraic chess notation).

Use of these annotation symbols is subjective, as different annotators use the same symbols differently. Moreover, an annotator's use of symbols is often influenced by the player's strength: a positional misjudgment that an annotator might give a "??" if played by a strong grandmaster might pass unremarked if played by a beginner.

Annotators' use of punctuation also may possibly be influenced by the result of the game (regardless of the actual quality of the move); one possible example came in the 11th game of the 1972 World Championship, when Spassky played an unexpected move, 14.Nb1, retreating the knight to its initial square. Spassky won the game, and several annotators gave the move two exclamation points. Edmar Mednis asserted that if Spassky had lost the game, the move would likely have been given two question marks instead.

Computer chess

Computer chess is computer architecture encompassing hardware and software capable of playing chess autonomously without human guidance. Computer chess acts as solo entertainment (allowing players to practice and to better themselves when no sufficiently strong human opponents are available), as aids to chess analysis, for computer chess competitions, and as research to provide insights into human cognition.

Current chess engines are able to defeat even the strongest human players under normal conditions. Whether computation could ever solve chess remains an open question.

Availability

Chess-playing computers are now accessible to the average consumer. From the mid-1970s to the present day, dedicated chess computers have been available for purchase. There are many chess engines such as Stockfish, Crafty, Fruit and GNU Chess that can be downloaded from the Internet for free. These engines are able to play a game that, when run on an up-to-date personal computer, can defeat most master players under tournament conditions. Top programs such as the proprietary Shredder or Fritz or the open source program Stockfish have surpassed even world champion caliber players at blitz and short time controls. In October 2008 Rybka was rated top in the CCRL,CEGT, CSS,SSDF, and WBEC rating lists and has won many recent official computer chess tournaments such as CCT 8 and 9, the 2006 Dutch Open Computer Championship, the 16th IPCCC, and the 15th World Computer Chess Championship. As of February 03, 2016, Stockfish is the top rated chess program on the IPON rating list.