This article uses algebraic notation to describe chess moves.

Kasparov versus The World was a game of chess played in 1999 over the Internet. Conducting the white pieces, Garry Kasparov faced the rest of the world in consultation, with the World Team moves to be decided by plurality vote. Over 50,000 individuals from more than 75 countries participated in the game. The host and promoter of the match was the MSN Gaming Zone, with sponsorship from the bank First USA.^[1] After 62 moves played over four months Kasparov won the game. In his words:

It is the greatest game in the history of chess. The sheer number of ideas, the complexity, and the contribution it has made to chess make it the most important game ever played.^[1]

[edit] Pre-game speculation and preparation

Prior to the game, Kasparov was considered a prohibitive favorite. He was reigning World Champion, he was playing with the advantage of the white pieces, and previous examples of majority Internet voting had produced mediocre competition. For example, Anatoly Karpov had taken the black pieces against the rest of the world earlier that year, and had won convincingly. Contrary to expectations, however, Kasparov's game produced a mixture of deep tactical and strategic ideas, and although Kasparov won, he admitted that he had never expended as much effort on any other game in his life.^{[citation needed]}

The World Team had several points in their favour, some of which were innovative for an Internet game. Firstly, four young chess stars were selected by MSN to suggest moves for the World Team. They were, in decreasing order of FIDE rating, Etienne Bacrot, Florin Felecan, Irina Krush, and Elisabeth Paehtz. Also, grandmaster Daniel King, recruited to provide a running commentary, often acted as a fifth advocate. Secondly, the moves were slowed down to a pace of one move per day; that is, Kasparov had 24 hours to consider each of his moves, and the World Team had 24 hours to respond. Thirdly, MSN provided a bulletin board for the discussion of the team's moves. It was hoped that these advantages would collectively allow for true consultation, and raise the level of play.

Kasparov played his first move 1.e4 on June 21, and the World Team voted by a 41% plurality to meet him on his home turf with the Sicilian Defence.

[edit] The game

White:Garry Kasparov

Black:The World

Opening: Sicilian Defence, Canal Attack, ECO:B52

[edit] Moves 1-10

Garry Kasparov - World Team
Sicilian Defence, B52

Position after 3.Bb5+. Kasparov chose to move into a closed game after the World Team chose his favorite Sicilian Defence. He apologized later for this move.

1.e4 c5 2.Nf3 d6 3.Bb5+

Kasparov's third move was the first real surprise of the game. He typically plays the more ambitious 3.d4 in this position, immediately opening the game. His actual move is more likely to result in a closed game with only a strategic pull for White. Kasparov apologized to the World Team for this move, but excused himself in light of his upcoming match for the World Championship against Vladimir Kramnik in 2000. Presumably he had prepared some innovations in his main lines, and did not want to reveal them in advance.

3...Bd7 4.Bxd7+ Qxd7 5.c4

Some viewers wanted Black to play 4...Nxd7, but were outvoted by those who thought Black's queen was safe on the light squares with White's light bishop off and thought Black stronger with its knight on c6. With c4, Kasparov solidified his hold on the d5 square by advancing the c-pawn before developing his queen's knight, which joined the attack on d5 on the next move. The resulting pawn formation for White is sometimes called the Maróczy Bind, a way of cramping Black's position. The World Team responded by contesting control of the d4 square.

5...Nc6 6.Nc3 Nf6 7.0-0 g6

Now Black must try to castle on its King-side and can set it up by freeing its dark bishop to either the e or g files. Rather than move the e-pawn to e6 or e5 and have the dark bishop blocked by its d-pawn, the World Team opted to fianchetto its remaining bishop, further contesting the dark central squares. Kasparov immediately broke up the center with his queen's pawn, before the black bishop could come to bear.

8.d4 cxd4 9.Nxd4 Bg7 10.Nde2

The center was too hot for the white knight on d4, because the World Team was threatening a discovered attack by moving the black knight away from f6, unmasking the g7 bishop. Exchanging knights on c6 would have been silly for Kasparov, as it would have brought a black pawn to c6, giving the World Team greater control of d5; instead a retreat was in order. All of Kasparov's moves up to this point were considered good according to opening theory of the time, but the line has since fallen out of favor, precisely because of what occurred next in this game. If White had wanted to achieve the strategic aims of this opening line, i.e. cramping Black's position without allowing counterplay, then either a different move (10.Nc2) or a different move order was necessary.

After 10...Qe6!. This was a novelty by the World Team that blew the game wide open. The black queen is forking two central pawns and White can not save them unless it joins battle for the center.

10...Qe6!

Black finally secured the opportunity to castle but refused to be so defensive. This move was a novelty by the World Team, i.e. a move which had never before been played in a recorded game. Krush discovered and analyzed the move, and enlisted Paehtz to recommend it as well, to give it a better chance of winning the vote. Their combined advocacy, plus much discussion on the bulletin board, was enough to gain it 53% of the vote. After this move, MSN requested that the four official analysts not coordinate with each other, perhaps to ensure a greater variety of recommendations. The analysts worked in isolation from each other thereafter.^{[citation needed]}

By this point in the game, several aspects of the cooperation within the World Team had become apparent:

• It was clear from a look at the voting results that, although the World Team was managing to pick theoretically correct moves, many rank amateurs were voting as well. Demonstrably bad moves were garnering a significant percentage of the votes; even worse, on move 12, about 2.4% of the voters chose illegal moves which did not get the World Team out of check.

• The World Team was not coordinating well with itself on the bulletin board. Typical posts were brash, emotionally heated, and confrontational; profanity flowed freely. Much more energy was being spent on flame wars than on analysis.

The tenth move was a turning point for the World Team, not only because it increased Krush's stature and energized the World Team, but because it blew the position on the board wide open. The black queen forked Kasparov's central pawns; he could not save them both. Counterattacking with 11.Qb3 would have been met by 11...0-0 12.Qxb7 Rfc8, and the World Team would have won back a central pawn with a favorable game. Kasparov was forced to enter the maelstrom with the next several moves.

[edit] Moves 11-20

After 14...axb6. The position is now materially even but Black has a lead in development and control of the center to compensate for the doubled pawns and centralized King.

11.Nd5 Qxe4 12.Nc7+ Kd7 13.Nxa8 Qxc4 14.Nb6+ axb6

After forced moves on both sides, Kasparov made a desperado move with his knight to double the World Team's pawns. Materially the game was still even, with a knight and two pawns balancing a rook. Positionally, the World Team had the disadvantages of doubled pawns and a centralized king, but the advantage of a lead in development and a central pawn mass. With no central pawns, Kasparov had no obvious way to expose the black king. In the judgment of most commentators, the World Team was at least equal, and it was perhaps Kasparov who was fighting uphill.

Kasparov rose to the challenge with an excellent move picked from alternatives which would have let the World Team take a strong initiative. For instance, it was tempting to harass the black queen and possibly fianchetto the white queen with 15.b3, but this would have invited the World Team to switch wings and initiate a kingside attack with 15...Qh4. Or, to blindly follow the rule "never move a piece twice in the opening when you can develop another piece" with 15.Be3 would have allowed the World Team to play 15...Nd5, bringing the black knight to the square it most fervently wished to occupy. Kasparov's actual move contested d5, somewhat blunted the effect of the black bishop on g7, and retained a compact, flexible position.

15.Nc3!

On the fifteenth move the World Team hotly debated a number of promising alternatives, including 15...e6 (still contesting d5), 15...d5 (occupying d5 outright!), 15...Ne4 (trading off Kasparov's best-placed piece), 15...Rd8 (intending to artificially castle and mobilize the central pawns), 15...Ra8 (pressuring the queenside and threatening a rook lift via a5), and 15...b5 (threatening to dislodge the white knight and pressure the queenside). The plethora of strong options available to the World Team was reflected in the analysts' recommending four different moves.

By this point in the game, several chess clubs had begun posting daily analysis to complement what was available on the official bulletin board and Web site of the game. The weightiest of these was the GM School, a consortium of Russian grandmasters. For the World Team's 15th move, they recommended 15...b5, along with Paehtz. Some people expected the unofficial recommendation of the GM School to be influential, particularly when the official analysts could not agree, but 15...b5 came in a distant second with 15% of the vote. In first place was Jon Speelman's idea of 15...Ra8 with 48% of the vote.^[1]

15...Ra8

The results of the vote were a reflection of the increasing coordination of the World Team. Krush was maintaining an analysis tree, and continually updating with all the suggestions and refutations from the bulletin board. Not only did the analysis tree allow the World Team to work with less duplication of effort, it served as a standing, detailed argument for the correctness of the recommended move.

In short, Krush was facilitating two tasks simultaneously: not only discovering a good move, but building a consensus that it was indeed a good move. Given that she had become the center of all the cooperative effort of the World Team (as opposed to individual effort, however heroic), even players of much greater strength began sharing their ideas with her, so that she would incorporate them into her analysis. In particular, Alexander Khalifman of the GM School struck up a constructive correspondence with her.^{[citation needed]}

16.a4!

This move was directed at the World's maneuverer 16...Ra5, which could now be met by 17.Nb5!, paralyzing the black queenside. Simultaneously, Kasparov threatened a rook lift of his own via Ra3, which could disrupt Black's plans in several continuations. Finally, 16.a4 prevented the World Team's doubled b-pawns from advancing, thus making them future targets. The game remained very unclear and dynamic, but it suddenly appeared to be the World Team which was fighting to retain its balance.

Again for the 16th move the four analysts made four different recommendations. This time Krush's suggestion of 16...Ne4 garnered 50% of the vote to 14% for 16...Nd4 in second place.

After 18.Qb3. Kasparov responded to the aggressive play of the World Team with a fork by his Queen. The World Team however, aided by Alexander Khalifman, found suitable counterplay.

16...Ne4 17.Nxe4 Qxe4 18.Qb3

On its 16th move, The World Team forced Kasparov to trade off his only piece that was not on the back rank, and simultaneously unmasked the action of the g7 bishop. Kasparov responded with a queen fork of the black pawns on b6 and f7. The loss of a pawn appeared unavoidable, but the World Team uncovered ways to gain some counterplay. The bulletin board debate raged between playing 18...e6 19.Qxb6 Nd4, to make sure it was the weak doubled pawn which went missing, or the more aggressive immediate 18...Nd4, allowing 19.Qxf7. Khalifman, however, found the extremely subtle move 18...f5, and after chewing it over, the bulletin board was more or less convinced.

The strength of the bulletin board consensus was tested when the other three analysts unanimously recommended 18...Nd4. The vote came out with 43% in favor of Krush's recommendation of 18...f5, and 35% in favor of the otherwise unanimous recommendation of 18...Nd4. This sparked loud grumbling on the bulletin board that Krush had "taken over the game". Those who complained were not overstating Krush's influence; her recommendations were selected every single move from the 10th to the 50th.

18...f5!

The World Team conceded Kasparov the b6 pawn, but for a price. After 19.Qxb6 Nd4, the World Team would have had dual threats of Nc2 and Ra6, ensuring very active play for the pawn. If instead Kasparov continued developing with 19.Be3, the World Team could have offered a queen trade with 19...Qb4, and banked on the central pawn mass to be quite strong in any endgame. But rather than these, Kasparov once again found a powerful continuation: a developing move with stronger attacking possibilities.

19.Bg5

Kasparov, up against much stiffer resistance from the World Team than he had imagined possible, began to drop hints that he was effectively playing against the GM School, and not against the Internet as a whole, but move 19 (among others) debunked that theory. The GM School recommended 19...Qd4, while the bulletin board found a flaw in their analysis, and generally favored 19...Qb4 as being more forcing. Furthermore, for much of the game, a few top grandmasters of the GM School were busy with other commitments, and the World Team analysis was driven instead by a handful of dedicated IM's and FM's, along with dozens of amateurs exploring and double-checking countless lines with strong chess software.

On this particular move, the voting was further complicated by a large faction in favour of 19...Nd4, with a counter-attack, and this was the recommendation of both Felecan and Paehtz. The winning total of 35% for 19...Qb4 was the lowest winning total for any move of the game, perhaps because the move essentially forced Kasparov to intensify his attack on the kingside. Note that a queen trade was strategically out of the question for White, as it leads to a favourable endgame for Black.

After 20.Qf7. Black can grab a pawn and protect its bishop with 20...Qxb2. But this puts terrific pressure on the e7 pawn and the Black King.

19...Qb4 20.Qf7

On move twenty it was tempting for the World Team to grab a pawn and protect the g7 bishop with 20...Qxb2, daring the white rooks to occupy whichever files they chose, but in many continuations the World Team's king would sit rather uncomfortably in the center. After much debate on the bulletin board, no clear refutation of the pawn grab was discovered, but it was still deemed too risky by many. Bacrot, Felecan, Paehtz, and King independently agreed, and by a large margin the World Team decided to protect its bishop and close the e-file with

20...Be5

Kasparov of course did not fall for the simple trap of grabbing the h-pawn, because 21.Qxh7 Rh8 (skewering Kasparov's queen and h-pawn) 22.Qxg6 Bxh2+ 23.Kh1 Qg4 would have won at least a piece for the World Team. Instead he opted for a simple defensive move which restored his threat to plunder the black kingside.

[edit] Moves 21-30

21.h3

A few World Team members favored shoring up the kingside with 21...Rh8, effectively admitting that the 15th move was a mistake. To defend in that way would have left Black with a very passive position, and invited Kasparov to activate his pieces. Instead, the World Team opted to play actively, exchanging the kingside pawns for Kasparov's queenside pawns. This line showed that the pressure the black rook exerted on the queenside was not illusory, and Kasparov's reply on move 16, albeit brilliant, did create a weakness.

After 25...Bd4. The game has now started to become an endgame. White and Black are in a race to get their h- and b-pawns respectively, promoted.

21...Rxa4 22.Rxa4 Qxa4 23.Qxh7 Bxb2 24.Qxg6 Qe4 25.Qf7 Bd4

The dust settled, and the material was still even, with a rook balancing a knight and two pawns. With a pair of rooks exchanged, and neither side having pawn levers to use against the enemy king, both kings were safe enough that direct attacks became less likely. Therefore, although the queens remained on the board, the game started to take the character of an endgame, with the struggle to promote a pawn rising to the foreground. Indeed, Kasparov could have immediately begun marching his h-pawn forward, and the World Team would have had difficulty restraining it. On the other hand, the World Team's b-pawn would have been able to advance equally quickly, making the position very double-edged. Rather than launching the race at once, Kasparov made a subtle move to tie down the World Team into a more passive position.

26.Qb3

Kasparov hit at the weak b-pawn, and prepared Be3. The World Team did not want to trade bishops, and considered the consolidating move 26...Bc5 so that 27.Be3 could be met with 27...Nd4. However, Kasparov had the even deeper threat of first using his queen to help his rook into play. After 26...Bc5 27.Qb1!, the World Team could not have accepted a queen exchange which would bring the white rook to life, but moving away the queen would allow 28.Re1, and suddenly the white pieces would be coordinating very well.

In keeping with its play throughout the game, the World Team found a sharp, active alternative in 26...f4, which extensive analysis showed to be at least as good as 26...Bc5. However, Krush's recommendation on behalf of the bulletin board once again stood alone against the unanimous recommendations of the other three analysts. In an extremely close vote, 26...f4 edged out 26...Bc5 by a margin of 42.61% to 42.14%.

26...f4!

The World Team blocked off Kasparov's bishop from its na