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The first-move advantage in chess is the inherent advantage of the player (White) who makes the first move in chess. Chess players and theorists generally agree that White begins the game with some advantage. Since 1851, compiled statistics support this view; White consistently wins slightly more often than Black, usually scoring between 52 and 56 percent. White's winning percentage〔 White's overall winning percentage is calculated by taking the percentage of games won by White plus half the percentage of drawn games. Thus, if out of 100 games White wins 40, draws 32, and loses 28, White's total winning percentage is 40 plus half of 32, i.e. 56 percent.〕 is about the same for tournament games between humans and games between computers. However, White's advantage is less significant in blitz games and games between novices. Chess players and theoreticians have long debated whether, given perfect play by both sides, the game should end in a win for White, or a draw. Since approximately 1889, when World Champion Wilhelm Steinitz addressed this issue, the overwhelming consensus has been that a perfectly played game would end in a draw. However, a few notable players have argued that White's advantage may be sufficient to force a win: Weaver Adams and Vsevolod Rauzer claimed that White is winning after the first move 1.e4, while Hans Berliner argued that 1.d4 may win for White. Some players, including World Champions such as José Raúl Capablanca, Emanuel Lasker, and Bobby Fischer, have expressed fears of a "draw death" as chess becomes more deeply analyzed. To alleviate this danger, Capablanca and Fischer both proposed chess variants to renew interest in the game, while Lasker suggested changing how draws and stalemate are scored. Since 1988, chess theorists have challenged previously well-established views about White's advantage. Grandmaster (GM) András Adorján wrote a series of books on the theme that "Black is OK!", arguing that the general perception that White has an advantage is founded more in psychology than reality. GM Mihai Suba and others contend that sometimes White's initiative disappears for no apparent reason as a game progresses. The prevalent style of play for Black today is to seek dynamic, unbalanced positions with active counterplay, rather than merely trying to equalize. Modern writers also argue that Black has certain countervailing advantages. The consensus that White should try to win can be a psychological burden for the white player, who sometimes loses by trying too hard to win. Some symmetrical openings (i.e. those where both players make the same moves) can lead to situations where moving first is a disadvantage, either for psychological or objective reasons. ==Winning percentages== In 1946, W.F. Streeter examined the results of 5,598 games played in 45 international chess tournaments between 1851 and 1932.〔 Also available on DVD (page 167 in "Chess Review 1946" PDF file on DVD).〕 Streeter found that overall White scored 53.4% (W: 38.12; D: 30.56; L: 31.31).〔The letters W, D, and L refer to the percentage of games won, drawn, and lost, respectively.〕 White scored 52.55% in 1851–78 (W:45.52; D: 14.07; L: 40.41), 52.77% in 1881–1914 (W: 36.89; D: 31.76; L: 31.35), and 55.47% in 1919–32 (W: 36.98; D: 36.98; L: 26.04).〔 Streeter concluded, "It thus appears that it is becoming increasingly difficult to win with Black, but somewhat easier to draw."〔〔Streeter stated in the article that of the total of 5,598 games surveyed, White won 2,134, drew 1,711, and lost 1,753. These included 782 games from 7 tournaments beginning with London 1851 and ending with Paris 1878, of which White won 356, drew 110, and lost 316; 3,445 games from 22 tournaments beginning with Berlin 1881 and ending with St. Petersburg 1914, of which White won 1,271, drew 1,094, and lost 1,080; and 1,371 games from 16 tournaments beginning with Berlin 1919 and ending with London 1932, of which White won 507, drew 507, and lost 357.〕 Two decades later, statistician Arthur M. Stevens concluded in ''The Blue Book of Charts to Winning Chess'', based on a survey of 56,972 master games that he completed in 1967, that White scores 59.1%.〔Stevens 1969, p. XXIII. Of the 56,972 games Stevens collected, White won 26,445 (46.4%), drew 14,579 (25.6%), and lost 15,948 (28.0%). ''Id.''〕 However, Stevens assembled his games from those that had been published in chess magazines, rather than complete collections of all the games played in particular events.〔Stevens 1969, p. XIV.〕 More recent sources indicate that White scores approximately 54 to 56 percent. In 2005, GM Jonathan Rowson wrote that "the conventional wisdom is that White begins the game with a small advantage and, holding all other factors constant, scores approximately 56% to Black's 44%".〔Rowson 2005, p. 193.〕 International Master (IM) John Watson wrote in 1998 that White had scored 56% for most of the 20th century, but that this figure had recently slipped to 55%.〔 The website Chessgames.com holds regularly updated statistics on its games database. As of January 12, 2015, White had won 37.50%, 34.90% were drawn, and Black had won 27.60% out of 739,769 games, resulting in a total White winning percentage of 54.95%.〔These percentages can be found here: (【引用サイトリンク】 title=Statistics of www.chessgames.com )〕 New In Chess observed in its 2000 Yearbook that of the 731,740 games in its database, White scored 54.8% overall; with the two most popular opening moves, White scored 54.1% in 349,855 games beginning 1.e4, and 56.1% in 296,200 games beginning 1.d4. The main reason that 1.e4 was less effective than 1.d4 was the Sicilian Defence (1.e4 c5), which gave White only a 52.3% score in 145,996 games.〔 A graph similar to that in the 2000 Yearbook can be found at (【引用サイトリンク】 title=How to Read NIC Statistics (Valid till volume 62) ) The New in Chess statistics just give the number of games played and White's overall winning percentage without breaking it down into white wins, draws, and black wins.〕 Statistician Jeff Sonas, in examining data from 266,000 games played between 1994 and 2001, concluded that White scored 54.1767% plus 0.001164 times White's Elo rating advantage, treating White's rating advantage as +390 if it is better than +390, or −460 if it is worse than −460. He found that White's advantage is equivalent to 35 rating points, i.e. if White has a rating 35 points below Black's, each player will have an expected score of 50%. Sonas also found that White's advantage is smaller (53%) in rapid games than in games at a slower ("classical") time control.〔(【引用サイトリンク】 title=The Sonas Rating Formula — Better Than Elo? )〕 In the 462 games played at the 2009 World Blitz Chess Championship, White scored only 52.16% (W38.96 D26.41 L 34.63).〔(【引用サイトリンク】 title=World Blitz Championship: Carlsen wins by three-point margin )〕〔(【引用サイトリンク】 title=Interesting tidbits about World Blitz Championship )〕 Other writers conclude that there is a positive correlation between the players' ratings and White's score. According to GM Evgeny Sveshnikov, statistics show that White has no advantage over Black in games between beginners, but "if the players are stronger, White has the lead".〔Adorján 2004, p. 69 (statement by Sveshnikov dated May 12, 1994).〕 An analysis of the results of games in ChessBase's Mega 2003 database between players with similar Elo ratings, commissioned by GM András Adorján, showed that as the players' ratings went up, the percentage of draws increased, the proportion of decisive games that White won increased, and White's overall winning percentage increased.〔Adorján 2004, pp. 67–68.〕 For example, taking the highest and lowest of Adorján's rating categories of 1669 games played by the highest-rated players (Elo ratings 2700 and above), White scored 55.7% overall (W26.5 D58.4 L15.2), whereas of 34,924 games played by the lowest-rated players (Elo ratings below 2100), White scored 53.1% overall (W37.0 D32.1 L30.8).〔Adorján 2004, p. 68. Of the 1669 games played by the highest-rated players, White won 442, drew 974, and lost 253. Of the 34,924 games played by the lowest-rated players, White won 12,700, drew 11,015, and lost 10,579.〕 Adorján also analyzed the results of games played at the very highest level: World Championship matches. Of 755 games played in 34 matches between 1886 and 1990, White won 234 (31.0%), drew 397 (52.6%), and lost 124 (16.4%), for a total white winning percentage of 57.3%.〔Adorján 2004, p. 154.〕 In the last five matches in Adorjan's survey, all between Anatoly Karpov and Garry Kasparov, White won 31 (25.8%), drew 80 (66.7%), and lost 9 (7.5%), for a total white winning percentage of 59.2%. Chess Engines Grand Tournament (CEGT) tests computer chess engines by playing them against each other, with time controls of forty moves in one hundred and twenty minutes per player (40/120), and also 40/20 and 40/4, and uses the results of those games to compile a rating list for each time control. At the slowest time control (40/120), White has scored 55.4% (W34.7 D41.3 L24.0) in games played among 38 of the strongest chess engines (as of May 27, 2009).〔Out of 22,592 games, White won 7,843, drew 9,321, and lost 5,423. (【引用サイトリンク】 title=CEGT 40/120 Rating List )〕 At 40/20, White has scored 54.6% (W37.0 D35.2 L27.8) in games played among 284 engines (as of May 24, 2009).〔Of 327,112 completed games, White won 120,982, drew 115,146, and lost 90,984. (【引用サイトリンク】 title=CEGT 40/20 Rating List )〕 At the fastest time control (40/4), White has scored 54.8% (W39.6 D30.5 L30.0), in games played among 128 programs (as of May 28, 2009).〔Of 470,740 games, White won 186,275, drew 143,409, and lost 141,056. (【引用サイトリンク】 title=CEGT 40/4 Rating List )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「First-move advantage in chess」の詳細全文を読む スポンサード リンク
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