A Closer Look at the Potkin-Grischuk Pawn Ending

In the second tiebreak game of the fourth round match between Vladimir Potkin and Alexander Grischuk from the World Cup, Potkin voluntarily entered the following king and pawn ending:

(Potkin-Grischuk, round 4.4. Position after 39.Kxe1.)

It seemed lost to me before I knew the result or checked with an engine. He did indeed lose, and the one part of it I did check with an engine before writing my summary article on the tiebreaks confirmed my suspicions. What I checked was whether White could hold the position if he refrained from playing b4 (after a3), and when I worked out to my satisfaction that he couldn't, I just assumed that it was a simple win and that the course of the game bore it out.

Wrong! Grischuk won, and the position was objectively won, too, but it wasn't trivial. In fact, Grischuk erred and let the win slip, only to have Potkin give away the half point on his very next move. In a slow game, with a reasonable amount of time to think, Potkin would have worked out the draw though Grischuk wouldn't have given him the opportunity in the first place. All the same, it's a good exercise for the diligent reader to try to work out the ending from the diagram.

The first crucial moment, alluded to two paragraphs ago, comes after 39...Ke6 40.Kd2 Kd5 41.Kc3 Kc5 42.a3 Kd5.

How does Black win if White refrains from 43.b4, and chooses instead 43.h3?

Second, after 43.b4 axb4+ 44.axb4 h6 45.h3 h5 46.h4:

How should Black continue? Try to work it out to the end.

The game, with my fairly deep analysis of the pawn ending, is here.

World Cup 2011: Round 4 Tiebreaks

And then there were eight.

The bloodbath continued today, with only three draws in the 20 games played, for a total of eight draws in 36 games for the round overall. (Soon the little-known GMs Vonahzdmisak and Vopihs will propose some radical measures to lower the excessive quantity of decisive games. Since a properly-played chess game should almost certainly be drawn, the high level of wins suggests a certain lack of competence in top-level play. Accordingly, if a game is won - especially if it is won too quickly - one suggestion is that the players replay their game with colors reversed with the previous time limit doubled. But I digress...) The games have been very exciting, if not always perfectly played.

Let's start with the bare facts and the pairings for the next round, and then we'll summarize the matches.

Polgar 4.5 - Dominguez 3.5 (that's the total score; the tiebreak score was 3.5-2.5 in her favor)
Ivanchuk 3 - Bu Xiangzhi 1 (2-0)
Ponomariov 4.5 - Bruzon 3.5 (3.5-2.5)
Gashimov 4 - Nielsen 2 (3-1)
Grischuk 2.5 - Potkin 1.5 (1.5-.5)

Quarterfinal Pairings (higher-rated player listed first, pairings given in bracket order):

• Svidler - Polgar
• Ponomariov - Gashimov
• Ivanchuk - Radjabov
• Grischuk - Navara

Now for the summary. Starting with the easiest, or at least most lopsided tiebreaker, Bu Xiangzhi went down without a fight to Vassily Ivanchuk. In the first game Bu had White in a Reti, but played it very passively and was already worse after 11 moves. He tried sacrificing first one pawn and then two, hoping that his bishops would give him some compensation, but they didn't and "Chuky" won easily. In the second game Bu tried the Czech Benoni, which is a reasonable way to at least avoid letting White kill the play from the start. Again Bu tried sacrificing a pawn for some play (Benko Gambit-style here, but with less effect thanks to the Black pawn on e5), but wound up just down a pawn for nothing. He tried following with further sacrifices, but Ivanchuk collected all the gifts and won with ease.

Grischuk-Potkin also finished in two games, but it wasn't anywhere near as easy. In the first game Grischuk didn't get anything with White from the opening. The game continued for a long time, with Grischuk generally having a very slight initiative, but it never became anything serious. In Potkin's white game, he repeated the aggressive anti-KID line that proved so effective in the first game of their match; naturally, Grischuk was better prepared this time. Instead of the (probably) dubious 7...Qe8 he went for the main line with 7...c6, which has scored very well in the past. The usual rejoinder is 8.Nf3, but Potkin went for 8.Qd2 instead. If it was an attempt at surprise, it boomeranged when Grischuk uncorked 8...d5, a new pawn sacrifice that looks completely sound. At a certain point Grischuk handled the position too slowly (e.g. 19...b5 probably improves on 19...a5), and Potkin started to consolidate the extra pawn. On move 22, it was probably best to swap rooks: 22.Rxe8+ Rxe8 23.Re1, when Black must either cede the file or draw closer to a two-results-only endgame. Instead, 22.b3?! b5! 23.cxb5?! Ne4! let Grischuk's pieces start jumping all over the place, and he soon regained his material and obtained the advantage. Eventually, Potkin rejected a bad rook ending for a completely lost pawn ending (exhaustion? time trouble?), and his great run came to an end.

Gashimov-Nielsen saw four decisive games in a row. Gashimov won the first rapid game with a slow Ruy, gradually building up a kingside attack that broke through. Nielsen won the rematch after a long, hard struggle. The key moments came on moves 34 and 42. Gashimov should have played 34...Rd8, not fearing 35.Nb5(?) as after 35...axb5 36.axb5 the king evacuates to safety starting with 36...Kd7. Instead, Gashimov's 34...Bxc3 was strongly met by 35.Qxd6! On move 42, Black could have kept some hopes alive with 42...Rh3: 43.Kg2 Rh2+ 44.Kxh2 Qxf2+ 45.Kh3 Qxf5+ 46.g4 Qh7+ 47.Kg2 Qe4+ 48.Kh2 and now either 48...Qe3 or 48...b6 keeps Black afloat. After Gashimov's 42...Nxf5, White obtained a winning endgame after 43.Qf4 Qxg3+ 44.Qxg3 Nxg3 45.Kg2 Ne4 46.Rxf7 and went on to equalize the match.

It was on to the 10-minute games (+10 second increments), and Gashimov again played a slow Ruy but eventually outplayed Nielsen to win again, and in the second game Gashimov went for the solid Schlechter Slav/Gruenfeld rather than repeating the Modern Benoni. It paid off, as he obtained an advantage out of the opening, and then the game and match were decided when Nielsen played 18.Be2??, an outright blunder costing him a piece. He kicked around a while longer - why not? - but there was nothing to be done, and he lost.

On now to Cuba vs. Europe, parts 1 and 2.

Starting with Ponomariov-Bruzon, Ponomariov won the first game by outplaying Bruzon from nothing on the white side of a Reti. The game was a nice illustration of how a knight can come to dominate a bishop even when that bishop isn't classically "bad". Bruzon struck back in game two with his own sideline opening, the Trompowsky. He didn't get anything from the opening either - or from the middlegame either, for that matter - but when Ponomariov blundered under pressure in the endgame, the match was tied. 42...Rd8 (preventing White's king from reaching d6) or 42...Rc8 (allowing the king to be driven back with ...Rc6+ after 43.Kd6 Ke8) would have held the balance. Instead, after the obvious but flawed 42...Ke7?/?? 43.Rf1 Rf8 44.Rxf8! Kxf8 45.Kd6 Black realized to his horror that the game cannot be saved. Even though Black could afford to lose everything if he can only eliminate the White e- and g-pawns (due to the bishop + wrong-colored rook pawn [or rook-pawn and wrong-colored bishop, if you prefer] problem), it couldn't be done.

With the psychological momentum, Bruzon won the first 10-minute game with Black, just overwhelming his opponent. Match over? Of course not! After an unusual and strategically complicated opening, Ponomariov managed to bring the position to an ending with two bishops vs. a bishop and knight, with both players having a-, g- and h-pawns. Objectively, it's probably a draw, but to hold it in what's essentially a blitz game against a great technician is nearly impossible. It took Ponomariov 47 moves from the start of that ending to win it, but win it he did.

On to blitz. Ponomariov drew the first game with Black without any adventures, and the match was finally decided in the next game. Ponomariov headed for a line where Black can win a piece for two pawns and a lot of risk, and Bruzon went for it. 17...Qd7 was natural but seems to be a mistake. Ponomariov was able to reach an ending with four connected passed pawns on the kingside as "compensation" for the piece, and while it took a while the fearsome foursome decided the issue: game and match, Ponomariov.

Finally, Polgar-Dominguez. Polgar won the first game very easily, gobbling up one pawn after another in a Grand Prix Attack sideline. A very convincing win, but then Polgar went against her style, choosing the rather bland, passive Scandinavian in an attempt to be solid. Dominguez won very easily, and the only drama was trying to figure out why Polgar continued as long as she did. (Maybe she felt Dominguez should have resigned the first game sooner than he did, and wanted "revenge"?)

Polgar won the first 10-minute game with a bit of luck; the kind of luck you get when you put a lot of pressure on your opponent. She burned too many bridges on the white side of a 6.Bc4 Najdorf, and while Dominguez had to be very careful, a few accurate moves would give him the win. Instead, successive errors on moves 27 and 28 took the position from won to equal to completely lost. (In case you're wondering, 27...Kg8 was winning and 28...Rg1+ 29.Kxg1 Bxh4 30.Qxh4 Rg8+ followed by 31...Rg6 holds the balance. In the rematch, Polgar again played the Scandinavian and again got a passive position out of keeping with her style. Dominguez won easily.

In the first five-minute game, Polgar replayed the line that was so successful in game one, but Dominguez played much better this time. Polgar might have had a slight edge early on, but Dominguez outplayed her and obtained a serious advantage. At least twice the advantage could have been decisive (30...Nc5, 41...Rd1+ followed by 42...Rc1), but after 41...Nxa5? White was better. In fact, with 45.Rh8+ and only next 46.e7 Polgar would have been winning, but both players were in serious time trouble at this point. The game was soon drawn, and both players seemed relieved to have survived.

Finally, Polgar returned to the Sicilian in the last game and reached a position similar to what would arise via her beloved Paulsen/Taimanov. Dominguez played by far his worst white game of the match, and after the oversight 19.h5?? was crushed after 19...Nxf3. His 20.Qg3 was even worse, but he probably felt that he'd have no chance in the endgame after the "correct" 20.Bxc7 Nxe1 21.Rxe1 Rxc7. Anyway, he had no chance after 20.Qg3 either, and Polgar finished with an iron hand.

Official site (with video coverage) here.

Gelfand's Game 6 Win Over Grischuk

It's here, with my annotations. Very impressive play by Boris Gelfand!

Candidates Final, Game 6: Gelfand Wins Game, Match, and the Right to Face Anand in 2012

It was almost a must-win situation for Boris Gelfand, as Alexander Grischuk would have been a favorite had the match come down to rapid and possibly blitz games. Remarkably, Gelfand came through with a convincing victory, and by doing so he won not only the game but the match as well, and thereby qualifies for a title shot against Viswanathan Anand in 2012.

The first thing Gelfand did right was to avoid the English! Instead, the opening was a Fianchetto Gruenfeld, featuring a line that has become very popular over the past year or so. Grischuk had the first new idea, but Gelfand seemed to have a better feel for the particular middlegame that arose. Gelfand stood better, and when Grischuk chose not to play 23...f5 but allowed e4 and then d5, it was as good as over. White's forces rolled through Black's position, and it turned into a massacre.

So a big congratulations to the 42-year-old Boris Gelfand, who was responsible for two of the three classical wins (out of 30 games) in the event. He has shown once again that even if it's an exaggeration to say that life begins at 40, it certainly doesn't end at that age, either - as the "youthful" 41-year-old Anand knows as well.

Game (with notes) later.

And Now for the Game Itself

Here's game five of the Candidates' final, with my notes.

Candidates Final: Game 5 is...Drawn

Who knew? That brings the totals to a whopping 27 draws in 29 games for the Candidates. Of course this is in part a function of the short matches and the rapid tiebreaks, but it's pretty depressing nevertheless, as the point of this exercise is to determine a challenger for the CLASSICAL World Championship, not the rapid title.

This general complaint doesn't really apply to today's draw, however. Grischuk came up with a new move for White in the QGD, pressed hard and had serious winning chances until a careless moment allowed the wily Gelfand to escape with a nice tactic. In fact, Gelfand had several neat tactical tricks the second half of the game that allowed him to escape with a hard-earned draw.

So tomorrow is the last classical game, and we'll see if Gelfand can finally break Grischuk in the 1.Nf3 c5 2.c4 Nc6 3.Nc3 e5 English, or if he tries a different approach altogether. It will also be interesting to see how much of a sense of desperation he feels, if any, about facing Grischuk in rapid or possibly blitz games. Recall that in their world championship match in 2010 Topalov took some crazy risks against Anand, arguably motivated by a similar fear of Anand's prowess at faster time controls, and lost the final classical game with White. Gelfand is far more risk-averse than Topalov, he might still feel some pressure to make something happen tomorrow. We'll see!

I'll have today's game (with notes) later on...stay tuned.

Candidates Final, Game 4: Dr(y)awn

Game 4 was another attempt by a Grischuk opponent to get something with White in the English, but - as usual - to no avail. Gelfand was quickly dissatisfied with his attempt to obtain an advantage and offered a draw on move 18. Grischuk, whose odds get better and better as they near the tiebreaks, took it after a minute's thought, and the match is now at 2-2 with two classical games to go.

The game, such as it is, can be replayed here with my light notes.

Grischuk On 9...b5, and What We Can Learn From This

In Chess in Translation's rendering of the postgame press conference of the last Grischuk-Gelfand game, Grischuk discusses Gelfand's great novelty:

Well, what can I say? 9…b5 is a very interesting novelty. It was a little unexpected, as after all the pawn’s under attack twice. In principle, however, it’s no wonder there’s such a possibility – after all, White first gave up the bishop for a knight, and then started jumping around with the queen: 7. Qb3, 8. Qxc4. And then Black has something dynamic and tactical like that. It wasn’t a great surprise for me.

Compare this to Sergey Shipov's characteristically colorful remark upon seeing 9...b5: "I nearly fell off my chair!" Shipov isn't as strong a player as Grischuk, of course, but he's no slouch. In his best days he reached a peak of something like 2662, so this isn't the exuberance of an amateur. I think two things are at work here. First, Shipov is a commentator and not a player, so he can be emotionally open. A competitors in the heat of battle ought to bolt his emotions, or at least keep them under control.

The second thing - and here's what I find most interesting - is this. Grischuk was surprised - he admits it (he doesn't admit that it was a "great" surprise, but it was a surprise nonetheless), and the picture in the first link suggests surprise as well. But what I really like about Grischuk's response is how he proceeds after acknowledging that the move was unexpected. He points to features of his own play that could justify a move like 9...b5, and that's doubly advantageous.

For one thing, it means he kept his objectivity. Rather than thinking 9...b5 "must be" bad, he recognized that he was in no position to cast the first stone against this "sinful" move. As a result, he didn't assume that the most ambitious approach must be correct, and instead worked hard to make sure that nothing went too terribly wrong.

Second, by telling such a story about his own "sins" (trading the bishop for the knight and making multiple queen moves), he kept his equanimity. Keeping his objectivity was a matter of maintaining proper rationality, while keeping his equanimity refers to the emotional side of things. Rather than getting his blood a-boiling, he could calm himself by realizing - or at least telling himself a story - that suggested that Gelfand's novelty had a full right to be played.

As a result, Grischuk kept his cool and his wits about him, got down to the hard work of thinking things through (no knee-jerk reaction here), and held the position. That's a good lesson for us as well, when we see a new, even shocking move in the opening. Keep your wits, philosophize about whether your opponent has a "right" to such moves, and then get to work!

Candidates Final, Game 3: A Short but Savory Draw

When I first saw today's game, after it was over, and observed that Grischuk drew with White in just 14 moves, I thought "Here we go again: Grischuk is using the same cynical strategy all over again of trying to draw his way to the blitz tiebreak!" But after looking carefully at the game, I don't think that was the case here. Grischuk tried a new approach against the Queen's Gambit Declined today, which already suggests that he was playing with some ambition, and what really shook things up was Gelfand's incredible novelty on move 9, 9...b5!! To all appearances it's completely sound, and Grischuk had to be very careful over the next few moves not to be worse. In the final position, it looks like approximate equality, with Gelfand having full compensation for a sacrificed pawn, but not more. Both players had to work at the board, and while the game certainly could have continued, it wasn't a pseudo-game like several of the Grischuk-Kramnik "battles".

The match is thus tied at 1.5-1.5, and will resume on Monday; Sunday is a rest day. Meanwhile, enjoy replaying today's game with my notes, which are fairly extensive, especially for a 14-move game!

This Week's ChessVideos Show: Grischuk-Gelfand, Game 1

It's just what the title suggests, so I'll forgo any further description and move on to the logistical information: the show is here, it's free (with free registration), and will be available on-demand for the next month or so.