The Machine: Coming Soon to a Theater Near You

At least if you live in London or New York. "The Machine" is a play revisiting the second match between Garry Kasparov and Deep(er) Blue, won by the computer when Kasparov cracked and disintegrated in the sixth and final game. Needless to say - unfortunately - the historical event is of no particular importance to the play; it's just offers a convenient scaffolding for whatever idea the playwright has in mind.

Here are a couple of representative quotes from playwright Matt Charman:

I didn't want to write a play that was just about chess. In fact, the chess is almost the least important part of the play.

[So what is the story about? What's the driving idea? The answer:] You've got these two guys [Kasparov, and Deep Blue's primary programmer and designer Feng-Hsiung Hsu] coming into America wanting what it's got to offer and, I think, both being seduced and ruined by it."

Huh? The match happened to be in the United States, but how is this a "coming to America" story? Kasparov had been here many times and has an apartment in New York, but he wasn't "coming" here for any interesting reason. As for Feng-Hsiung Hsu, he had been in the U.S. for over a decade, beginning with his time as a grad student. It's also hard to see how either person was "ruined". It was a blow for Kasparov, but his chess career and life continued successfully after that event. In fact, just two years later Kasparov began the best run of his chess career, winning something like seven consecutive super-tournaments and pushing his rating to a then-record of 2851. It was no blow for his human "opponent" either: he won, gained some fame, and has continued his very successful work in the computer industry.

So, if you have to miss one play this year, "The Machine" is it. In fact, I'd even consider leaving London or New York during the play's run.

Here's an obvious question for the playwright: why not just write an original story, preferably one that's not about chess? It seems to me that "historical fiction" is a fancy way of minimizing the need for originality and creativity and getting a little free PR (based on the familiarity of the principals or the historical events). Meanwhile, an author has the freedom to lie like a psychopath engage in a bit of artistic license, just as long as he hides behind the term "art" and includes a boilerplate disclaimer.

Please note: I'm not saying that there is anything slanderous or defamatory in this play. My point is that "historical fiction" is a genre that allows for defamation under the guise of "art". Thus while Charman's cartoons of Kasparov and Feng-Hsiung Hsu may produce characters who are just as praise- or blameworthy as the real individuals, it doesn't seem from the quotations that he has much concern for the principals' actual motivations.*

Another "winning" quote:

A piece of software beat the best and the brightest. What does that actually mean? We're suddenly not the smartest thing on the planet.

Er, no, that's not what it means, and it's hard to believe that any reasonably intelligent person who stops to think about that claim for a few moments could really believe it. I think we would all agree that Kasparov is an exceptionally intelligent individual, but few people would claim that he is - or at least was as of 1997 - the smartest person (or "thing") on the planet. It isn't even clear that intelligence is such a tight, unified concept that one can identify, even in principle, someone who is THE smartest person on the planet.

Comparatively speaking, that's a quibble; here's a more serious problem. We can grant that Deep Blue was a better chessplaying entity than Kasparov, but that's where its reputed intelligence ends. Deep Blue could only play chess, so all the things Kasparov could do that Deep Blue couldn't gives him an enormous plus in the intelligence department. Nor would reprogramming Deep Blue to perform other functions have solved the problem. Recognizing faces is a mundane and very routine skill for humans - even very young children have it down, and don't need to go to college to develop it. For computers, especially those of that era, it was a task at which they were utterly incompetent, and there are many other skills and feats that are routine for us and difficult-to-impossible for machines.

Even more fundamentally, Deep Blue couldn't have been the smartest thing on the planet, because it didn't have any smarts at all. Even if one thinks computers will eventually be conscious or thinks we are just really fancy biological computers ourselves**, no one believes that Deep Blue was conscious. (I don't recall anyone picketing IBM and accusing them of murder when they ended the project and used its processors for other tasks.) No one thinks an abacus is "smart". Useful, sure, but not smart. Unless there's someone "there", computers like Deep Blue are also useful - incredibly useful - but still not smart.

Enjoy the performance.

HT: Bob Banta

* Alert readers, especially those who disagree with what I'm writing, may think that I'm creating a caricature of Mr. Charman, and am thus guilty of doing what I've just criticized. In that case, consider this post as a satire. Now that it's art, the problem has been solved. See how easy that is?

** I grant neither assumption, or for that matter the assumption that the things we call computers exist as things in their own right as opposed to being collections of parts whose "unity" is a matter of performing functions of human interest, but I waive these challenges above for the sake of argument.

Thessaloniki Grand Prix, Round 7: Kamsky, Caruana Lead

It was a very good day for citizens of the United States at the FIDE Grand Prix tournament in Thessaloniki as they went three for three while no non-citizen managed to win. Two of them, Gata Kamsky and Fabiano Caruana (who holds dual citizenship but represents Italy) are tied for first, while the third, Hikaru Nakamura, got his first win of the event.

Kamsky's win was the cleanest, as he simply outplayed Rustam Kasimdzhanov with the black pieces in a Dutch Defense. Kasimdzhanov didn't make any obvious, egregious errors, but was beaten a bit at a time. The only really clear error came on move 27. White should have played 27.e4, temporarily sacrificing a pawn. His position was worse but wouldn't have been lost. Instead, he tried 27.exf4, but this opened the kingside files and Kamsky took speedy advantage.

Caruana's win wasn't so smooth. First one player and then the other had a very slight advantage, but it was Alexander Morozevich who was doing most of the pressing. The key moment came on move 47. Caruana threatened 47...Qb1+ 48.Nf1 Qxf1+ 49.Kxf1 Rh1#, and so Morozevich played 47.Nf1(??). That took care of the mate, but it was a blunder, and he was lost after 47...Nh3+!, forcing the win of the queen. Instead, 47.Nxf4 exf4 48.Nh5 sufficed for full equality. (Note that 48...Qb1+ 49.Kh2 Qxe4?? walks into mate starting with 50.Qc8+.) A nice gift for Caruana!

The third decisive game was Nakamura's win over Veselin Topalov. Nakamura quickly won a pawn, but in light of the locked pawn structure and Black's good knight vs. White's bad bishop, a draw was the likelier result. Nakamura thought that Topalov's decision to exchange the last pair of rooks was a mistake, though even after the trade it wasn't clear that White could win. After the game Nakamura believed he could have won more easily with 44.Bxg6, but this is a mistake: after 44...Kxg6 45.Ke5 Nf5! 46.d6 Nd4! 47.d7 Kf7! 48.Kd6 Ne6 49.f4 Kf6! it's a draw.

Another key moment came at move 50. Nakamura thought for half an hour on 50.f5 before playing it, and Topalov instantly replied with 50...Nd6, which looks like a serious (and fairly obvious) error. As Nakamura pointed out, Black needed to play 50...Kg7, aiming to park the king on f6 and bringing the knight back to d6. He didn't see a way to win after that, and it's not clear that there is one. (I'm not completely sure about that, but I'm not spotting one and the computer doesn't offer any sensible lines either.) Topalov's move allowed 51.f6, which in turns makes it possible for White's king to make further inroads.

Nevertheless, the adventures hadn't yet come to an end. After 54...Nxb5 White had any number of clear winning approaches; for example, 55.Be8 Nd6 56.f7 Kg7 57.Kg5 followed soon by Ke6, or 55...Nd4 56.Kg4 Nxb3 57.d6 Nd4 58.Bf7 Nc6 59.Kf5. In both cases, White is not just winning but easily winning. Instead though, Nakamura played 55.Be2, probably anticipating 55...Nd6 and intending to meet it with 56.Bd3, cutting off the Black king. Instead, Black played 55...Nd4!, and now Nakamura had to think. He was down to his last 4-5 minutes until the second time control (achieved by making the 60th move). He looked nervous and his time was dwindling, but to his credit he played the absolutely correct - and probably only winning move - 56.Bh5!! To make this move he had to accurately calculate that 56.Bd3 failed, to recognize that 56.Bh5 won, and to have the inner strength to undo his last move. After 56.Bh5, 56...Nf5+ was probably a better try, but Topalov was lost in any case.

The other three games were drawn, but only Bacrot-Dominguez merits mention. It was a very long game, but instructive in two ways. First, it shows both the strengths and the limits of the minority attack. White got what he wanted and saddled Black with a chronically weak c-pawn. That's the strength. On the other hand, Dominguez showed that the one weakness, by itself, wasn't the end of the world. He never had any counterplay, but even so it was very hard for White to convert this slight advantage into something major. The second instructive aspect came late in the knight ending, when Dominguez bravely and correctly sacrificed the aforementioned c-pawn with 60...Nd7. If Mikhail Botvinnik's maxim that "knight endings are pawn endings" were true, then White would have won. Instead, Black got just enough counterplay, and between that and White's backward e-pawn, Dominguez was able to hold the game.

Round 8 Pairings:

• Grischuk (4) - Caruana (5)
• Dominguez (4.5) - Morozevich (3.5)
• Topalov (3.5) - Bacrot (2.5)
• Kamsky (5) - Nakamura (3)
• Ponomariov (4) - Kasimdzhanov (3)
• Ivanchuk (1.5) - Svidler (2.5)

Thessaloniki Grand Prix, Round 6: Three Lead

Leinier Dominguez was the solo leader after five rounds of the Grand Prix tournament in Thessaloniki after winning three games in a row, and in round six he should have made it four in a row. Really should have made it. He had a big advantage against Hikaru Nakamura after just 10 moves, and after the nice shot 13.Bh6! Black was nearly busted. 13...0-0 was out of the question due to 14.Bxg7 Kxg7 15.Qg3+ followed by a knight check and 17.Qxc7. 13...Bf8 needed to be played instead, but Nakamura tried 13...gxh6 14.Qxf6 when Dominguez was probably winning. As usual, Nakamura defended tenaciously, and after the time control Dominguez let things slip.

As many as four players could have caught him in first, and two managed to do so: Fabiano Caruana (send him back!) and Gata Kamsky (thanks for sending him!). Kamsky kept Peter Svidler under pressure on the white side of an English (a Reversed Dragon) and outplayed him before the time control. Kamsky's minor pieces found their way to excellent outposts, and all Svidler could do was give up buckets of material trying for counterplay. Maybe it would have had a shot if Kamsky had to make his tough defensive decisions before the time control, but as he could do it instead just afterwards he (Kamsky) was able to win wiht ease. As for Caruana, it was a typical sort of victory in the Scotch over Etienne Bacrot. He sacrificed a couple of pawns to destroy Bacrot's structure, only to win it back with a pawn's interest on move 31. At that point Bacrot could have drawn if he could only liquidate the queenside pawns - IF. There was no simple way to achieve it, but the outcome was unclear until the rash 35...c4. That guaranteed that Black would lose the pawn for nothing, and once the players reached the time control Bacrot gave up.

Topalov-Kasimdzhanov and Grischuk-Morozevich were both Ruys that finished in a draw, but in both games one of the players had good winning chances: Kasimdzhanov in the first game and Grischuk in the latter. Finally, Ponomariov defeated the sinking Ivanchuk in just 19 moves. Chuky's 16...0-0-0 was very risky, while 18...Na7 blundered a pawn. After 19.a5 White wins at least a pawn, e.g. 19...Nbc8 20.bxc4 bxc4 21.Nxc4. As it won't just be a pawn but progress in pursuing the vulnerable Black king, Ivanchuk had enough and called it a day.

Round 7 Pairings:

• Ivanchuk (1) - Grischuk (3.5)
• Svidler (2) - Ponomariov (3.5)
• Kasimdzhanov (3) - Kamsky (4)
• Nakamura (2) - Topalov (3.5)
• Bacrot (2) - Dominguez (4)
• Morozevich (3.5) - Caruana (4)

Thessaloniki Grand Prix, Round 5: Dominguez the Sole Winner, Sole Leader

Coming into round 5 seven players led the FIDE Grand Prix in Thessaloniki, and only one - Rustam Kasimdzhanov had White. Normally we'd think this would give him a leg up, but instead he was the day's only loser. His opponent, Leinier Dominguez, has now won three in a row and enjoys the sole lead with 3.5 points. Dominguez played the solid Bogo-Indian, in shocking violation of the guild's policy of playing the Gruenfeld whenever possible, and was rewarded for his insouciance. Kasimdzhanov misassessed the rook ending he started to head for with the exchanging combination starting with 22.Qxe4 and directly permitted with 26.Rc5. The resulting ending wasn't lost but it was very difficult, and some neat moves like 28...Kf8, 33...Re2 and 39...Ke8 helped push White over the edge.

The other five games went in every direction. Ivanchuk-Kamsky was drawn in just 25 moves and in half an hour, but the other draws all made it to at least the second time control. Svidler-Topalov saw White gain an advantage after 23...Nf8, but the position re-equalized after the natural 26.Ne5. (26.Nd2 was better, even though it doesn't force Black to initiate the swap.) Ponomariov-Grischuk was a Berlin that always looked pretty comfortable for Black. Interestingly, Grischuk wasn't completely sure that the final position was drawn, so the endgame mavens among you may wish to delve and see.

Two games made it past move 80, both Gruenfelds. Bacrot-Morozevich saw Moro down the exchange in return for a pawn and a beautiful knight. Soon he was even a little better, and refused a draw by repetition. Soon he regretted it, and after inaccuracies on moves 60 and 61 and an outright error on move 64 (he needed to try 64...Nxb5) he was lost. The key moment came on move 66, when Bacrot had to decide which way to move the king: to the kingside, to deal with Black's most dangerous pawns, or to the queenside, to support his own passer and free his rook to deal with the pawns. He chose wrongly, keeping the king on the kingside with 66.Rb8 followed by 67.Ke4-f3. Instead, 66.Kd4 followed by 67.Kc5 probably won.

Nakamura-Caruana initially followed a somewhat similar trajectory: Nakamura's inaccuracies just before and after the time control turned an equal position into one that favored Black and may have been winning. Nakamura had some compensation for a couple of pawns, but had Caruana immediately started the plan he initiated a move later it might not have been enough. Instead of 45...c5, it would have been better to consolidate with 45...Kf7 and 46...Bc8 (or vice-versa). As things went, Nakamura got one of his pawns back, and while Caruana tried for a long time to win the resulting same-colored bishop ending he was unable to break through against Nakamura's accurate defense.

Round 6 Pairings:

• Grischuk (3) - Morozevich (3)
• Caruana (3) - Bacrot (2)
• Dominguez (3.5) - Nakamura (1.5)
• Topalov (3) - Kasimdzhanov (2.5)
• Kamsky (3) - Svidler (2)
• Ponomariov (2.5) - Ivanchuk (1)

Thessaloniki Grand Prix, Round 4: Seven Lead!

Two players won today in round 4 of the FIDE Grand Prix in Thessaloniki, Veselin Topalov and Leinier Dominguez, and as a result they share the lead with five others going into the first rest day.

Topalov blitzed Vassily Ivanchuk off the board in just 21 moves, but this was primarily Ivanchuk imploding rather than a collapse due to his opponent's heavy pressure. Topalov had a small initiative after 17.dxe6, but it shouldn't have been anything too worrisome after 17...Nxe6 18.Qa4+ Kf8. Black's king isn't where it wants to be, but White's kingside structure isn't a dream come true either. Instead, Ivanchuk played one bad move after another, and his reward was a lost piece and a terrible king.

Dominguez beat Peter Svidler after the latter failed to preserve his king in a queen and rook ending. Svidler needed to play the overtly passive 26...Qf8 rather than the more active-looking 26...Qb7. The question is which White piece to contain, and it turned out that it was more important to keep White's queen off e8 than White's rook from a7. 29.f5 left Svidler in trouble, but the game wasn't decided until Black played the natural but erroneous 33...Kh8. Understandably, Black wanted to avoid allowing Qxe6 to come with check; the more important detail was that Black needed to keep extra control over f7. Thus after 33...Kh8 34.f6 White threatens 35.Ra8+ Qxa8 36.Qxg7#. If Black played 34...Rc8, then 35.f7 wins right away thanks to the threat of 36.Qh5#. This wouldn't be a factor had Black played 33...Kg8, as 34.f6 Rc8 35.f7+ just blunders the pawn: 35...Qxf7. Black tried 34...Rc7 instead, but after 35.Rf1 (threatening to take on g7 and continue 37.Rf8+, mating) 35...Rf7 36.Rf3 White is mating; the only question is how much material Black wants to throw into the wood chipper to delay it by a few moves.

Of the four draws, I'll take note of two. Kamsky-Ponomariov was even throughout, except for one fascinating moment right after the first time control. Kamsky should have played 42.Rxc5, when he should be able to neutralize Ponomariov's pressure after 42...Rxe4 43.Qb1 (e.g. 43...Re2 44.Qf1, or 43...Rd4 44.Rd5 Rxc4 45.Rd8+ Kh8 46.Qb2 etc.). Instead he played 42.Nf6+, but after 42...Qxf6 43.Rxc5 he was fortunate that Ponomariov missed 43...Qe7, which basically wins on the spot. Black threatens White's rook, and also threatens 44...Qe1+ 45.Kg2 Re2, when White cannot save his queen and cover the mate threat starting with ...Qxf2+. 44.Rc6! is the best try, aiming to meet 44...Qe1+ 45.Kg2 Re2 with 46.Rxg6+! If Black takes the rook, White has perpetual check; if he tries instead 46...Kf8? White wins with 47.Qf5.

Fortunately for Black in this variation, but unfortunately for Ponomariov, who must rue the missed opportunity, Black can improve with 44...Qb7! Now the rook sac is in vain: 45.Rxg6+ fxg6 46.Qxg6+ Qg7, forces a queen trade. If the rook retreats, however, e.g. 45.Rc5, then Black forces a speedy mate with 45...Re1+ 46.Kh2 Qf3. Instead of the winning 43...Qe7, Ponomariov instead returned the queen to f3, and Kamsky managed to hold starting with 44.Qd2.

The other especially noteworthy draw was the mind-boggling battle between Morozevich and Nakamura. Rather than give any hints or clues about it, I'll leave it to you to replay, analyze and simply enjoy it on your own. I'll note only that it was a remarkably well-played game considering its wildness.

Tomorrow (Sunday) is a rest day, and on Monday round 5 will occur with these pairings:

• Ponomariov (2) - Grischuk (2.5)
• Ivanchuk (.5) - Kamsky (2.5)
• Svidler (1.5) - Topalov (2.5)
• Kasimdzhanov (2.5) - Dominguez (2.5)
• Nakamura (1) - Caruana (2.5)
• Bacrot (1.5) - Morozevich (2.5)

Thessaloniki Grand Prix, Round 3: Ivanchuk Loses A Won Game

Five of the six games in round 3 of the FIDE Grand Prix in Thessaloniki were drawn, and of the five four of them were logical; that is, neither side ever had a serious advantage. Kamsky-Grischuk was another story, as Kamsky had a huge time advantage and an outright win in his grasp with 27.Nxf7! Nxf7 28.Nxg6. White's attack is too strong, and Black has loose material on h5, f8 and e7. Kamsky waited one more move before firing away with his attack, but 29...Qa2+! (perhaps Kamsky had missed this a few moves back?) gave Grischuk just enough to survive. Enough to survive, but not to equalize: Kamsky could have played on with 34.Qh7+ Kf8 35.Qe4 (or likewise two moves later); instead, he took the repetition and called it a day - pretty understandably, taking into account his own vulnerable-looking king and the ridiculous (and loose) bishop on h2. (Note, however, that after 35...Qxh2? White has 36.Rg2 Qh1 37.Nh7+, when Black loses the rook on f6 for nothing [at least nothing but the bishop captured on move 35], as White will otherwise win Black's queen with a discovered attack.)

As for the one decisive game, it was a catastrophe for Ivanchuk. He had a colossal advantage against Dominguez, missing an easy outright win on move 26 with 26.Be5 (he had time, too, but it's one of those moves you either "see" quickly or you don't; more time is unlikely to help), and then a more subtle win on move 31 (31.Nxg7 Rxd6 32.Qe8+ Kh7 33.Nh5! - not too difficult either, if one has time on the clock) and yet a third win the next move (32.Nxg7 followed by 33.Ne8). Even after these errors he was still better, and would have had good winning chances after 37.Nf6+ or especially 37.Nc7. Instead, he uncorked the ridiculous 37.f4??, hanging his knight.

The finish was if anything even more amazing. Back in 2009 the same players had another time scramble. Ivanchuk knocked over some pieces then, and although he was winning at the time control he felt bad about the toppled pieces and offered a draw. In act of remarkable sportsmanship, Dominguez didn't take the knight but went for a perpetual check, to pay Ivanchuk back for the 2009 game, but Ivanchuk's flag fell on the last move of the time control and the arbiters declared the forfeit - even as Dominguez tried to declare the game drawn! Alas...

Round 4 Pairings:

• Grischuk (2) - Bacrot (1)
• Morozevich (2) - Nakamura (.5)
• Caruana (2) - Kasimdzhanov (2)
• Dominguez (1.5) - Svidler (1.5)
• Topalov (1.5) - Ivanchuk (.5)
• Kamsky (2) - Ponomariov (1.5)

Thessaloniki Grand Prix, Round 2

Aside from a 19-move draw between Dominguez and Ponomariov, the action in round 2 of the FIDE Grand Prix event in Thessaloniki was plentiful once more. The other two draws had more life: Bacrot-Kasimdzhanov tested the suddenly resurgent Exchange Gruenfeld with 8.Rb1, while Topalov-Kamsky was a more offbeat Gruenfeld that saw Kamsky do most of the pressing.

In none of those three games was anyone really close to winning, but that obviously can't be said about the other three contests. Morozevich-Svidler was a startling blowout, won by White in just 22 moves. Morozevich played the Spanish Four Knights, and Svidler played Rubinstein's well-known pawn sacrifice. Morozevich returned the pawn for queenside play, and it seems that Svidler was a bit too interested in making something happen on the kingside rather than neutralizing his opponent's queenside play. The plan with 16...e4 and 17...Rh6 was a bit too optimistic, and 18...Nh4 was far too optimistic. Moro calculated and captured his way to what was by the end an overwhelming victory.

The second decisive game went considerably longer, with Caruana grinding down Ivanchuk on the white side of a Ruy Lopez, Steinitz Variation. In fact Black's position was tenable for a long time, but 44...Kf6 was a mistake that let White's queenside passers decide the game. Black probably should have played 44...Ra6, and on 45.Rd5 Rba7, freezing White's a- and b-pawns for the time being. Failing to do so, he was quickly overrun.

Finally, the third game was still longer - it went 121 moves! Nakamura was again the victim, as he was in round 1, of an impressive technical endgame won by his opponent. Grischuk grabbed a couple of pawns on the white side of a Neo-Archangelsk Ruy, and although his pawn structure was pretty ugly he managed to keep his material advantage into an endgame. After White's 52nd move both sides had a rook and a dark-squared bishop, while White had doubled f-pawns and a d-pawn against Black's lone f-pawn. No pawns were exchanged for the rest of the game, but the rooks came off at move 90. White eventually won by combining threats to Black's f-pawn with the power of his passed d-pawn (the "principle of two weaknesses" in action). Not a pleasant start for Nakamura: two blacks, 190 moves, and zero points. At least he's warmed up.

Round 3 Pairings (Scores in parentheses):

• Kamsky (1.5) - Grischuk (1.5)
• Ponomariov (1) - Topalov (1)
• Ivanchuk (.5) - Dominguez (.5)
• Svidler (1) - Caruana (1.5)
• Kasimdzhanov (1.5) - Morozevich (1.5)
• Nakamura (0) - Bacrot (.5)

USCF Rating Changes

United States Chess Federation members with ratings below 2355 may be interested to know that their "K-factor" has changed. Now their ratings will be more volatile, which is good news if their ratings are going up; not so good if they're taking a plunge. At least you're forewarned!

HT: Allen Becker & Brian Karen.

Encyclopedia of Chess Combinations, 4th Ed.: A Short Review

Chess Informant (CI) - the publisher - doesn't just publish the Informant - the book. Case in point: the fourth edition of the Encyclopedia of Chess Combinations. This is an old-style CI book: there's no English (or any other natural language) in the body of the text; all you'll find are diagrams, chess notation, and their standard symbols. (One exception: at the top of the page the theme covered on that page is given in English; non-English readers are likely to find the equivalent in their language in the table of contents.)

Tactics books are a dime a dozen (metaphorically; the literal price is considerably greater), so what's different about this one; what do you get for your $44-51? For starters, you get a lot of puzzles: 3001, to be precise. In general, the positions are challenging. Often knowing the theme will give you a good idea about the first move (you won't be shocked to know that in most cases the first move in the puzzles from the chapter "Demolition of Pawn Structure" will involve sacrificing a piece for a pawn in the general vicinity of the victim's king), but that's almost never enough to fully and properly solve the puzzle. Until you're around 1900 or so, you're probably better off working on other tactics book (or software, or tactics websites).

If you are 1900 and up though, it's worth considering because the puzzles are sorted by themes, which is relatively rare for advanced tactics books. In my view both kinds of tactics books are valuable: those where the puzzles are divided up by themes and those where one has no advance idea of what to look for. There are 10 themes in the book, each further subdivided into three sub-sections: "combinations with attack on the king", "combinations to achieve equality", and "other combinations". The 10 themes, with my occasional explanations and/or comments in parentheses, are:

• Annihilation of Defense [Typically removing a piece that guards another piece or a key square.]
• Blockade [Blocking a line, an escape square, etc. Not to be confused with Nimzowitsch's idea.]
• Clearance [Freeing a square or line for the benefit of another piece.]
• Deflection [Drawing a defender away from another defensive responsibility.]
• Discovered Attack [Not necessarily a discovered check.]
• Pinning
• Demolition of Pawn Structure
• Decoy [Not to be confused with deflection. The idea here is to draw the target piece to a bad square.]
• Interference [A move that forces the defender to block a crucial defensive line.]
• Double Attack

If you're a strong player and already have an impressive collection of (unused) tactics books, I wouldn't claim that this is the book for you, the one that will finally make everything fall into place. If you don't have a lot of advanced tactics books though, and especially if you don't have any that are sorted by theme, then it's worth considering - especially since $44-51 for 3001 puzzles is a good ratio. It's not worth getting if it's your 15th tactics book (meaning an advanced book for an advanced player), but if it's your first or maybe even your fifth, it might be.

Ordering info from the publisher.

Ordering info for U.S. buyers.

Informants 113-115 On DVD

As I've already reviewed Informants 113, 114 and 115 when they come out in book form, I won't repeat here what I said though you can find the reviews of each by clicking on the links above. My conclusion about those volumes, and with the Informant in general, now that the publishers have revitalized this venerable series, is positive. They aren't for everyone, but for strong club players - around 1800-1900 and up - the volumes can be both instructive and entertaining.

If it sounds interesting and you haven't already purchased those volumes, this is an excellent way to do it. The price for buying the three-pack on disc is considerably less than the cost for getting each Informant one volume at a time. The books run about $38 a pop, while this three-pack goes for about $64 from the publisher's site. Add to the savings the convenience of being able to examine the games (and all the other sections too) using ChessBase, Chess Assistant a PGN viewer or even the proprietary Informant format and it's an all-around good deal.

So if you're interested in the Informant and don't yet have these issues, it's definitely worth considering - especially for U.S. buyers, who can get it here for $57 (plus shipping). Highly recommended (for stronger/more ambitious club players, and up).