Checkers, Anyone? Plus, Problem Pieces

by admin on March 18, 2017

Last night I won a game against Shredder in very amusing but also instructive fashion. The computer’s rating was set to 2124. (I’ve found that this rating gives me the best blend of success and challenge; setting the machine to 2300 or 2400 makes me get too accustomed to losing.)

checkers 1Position after 27. … Nh7. White to move.

FEN: r2b1rk1/1pq1nppn/p2p3p/P1pPpN2/R3P1PP/1P6/2PB1PBK/3Q2R1 w – - 0 28

As White here, I was very happy with my position. White has a space advantage on both sides of the board and Black has almost no counterplay. I was pretty sure that the idea behind Black’s last move was to try to win my h-pawn with … Nxf5 followed by … Bxh4, or at least to try to induce White to play h5. Black would then gain the square g5 for his pieces and it would become very difficult for White to open lines on the kingside.

I had the feeling this was a crucial position, so I took my one time-out here. What do you think White’s plan should be in this position? More precisely, what do you see as White’s greatest problem, and how can White address it?

To be even more specific, the two moves that I analyzed most seriously in this position were 28. Bh3 and 28. g5. Which one is better, and why?

The first move I looked at was 28. Bh3. (Actually, I thought a bit about 28. Bf3 first, but realized that I wanted to keep the d1-h5 diagonal open for the queen.) At first it seemed promising. If Black goes for the pawn with 28. … Nxf5 29. gf Bxh4? my attack is overwhelming after 30. Bxh6 Bf6 (30. … Bxf2 31. Rxg7+ Kh8 32. Rxh7+! also wins for White) 31. Qg4.

Looks great, right? But then I looked at the simple defensive move 28. … Nxf5 29. gf Kh8! and I couldn’t find a clear way for White to break through. The natural followup seemed to be 30. Qg4, which forces Black to play the really awkward-looking 30. … Bf6. But what does White do next? How does he build the pressure? The problem for White is that he has two pieces that are doing nothing: the bishop on h3 and the rook on a4. In the time it takes him to bring those pieces to relevant positions, Black will have time to play … Rg8, … Be7, maybe … Nf6, … Bf8 or … Nf8, and set up a really solid Maginot Line defense.

By contrast, the move 28. g5! immediately addresses White’s two biggest problems, the bishop on g2 and the rook on a4. White is telling Black, “Okay, you can win a pawn, but to do it you have to exchange on f5, which will free my rook to come to the kingside and free my bishop to do… Well, you’ll see what.” With 28. g5 I am getting all of my pieces into the attack; with 28. Bh3 I only got some pieces involved.

I think these arguments are so strong that one could almost play 28. g5 without analysis, but that wouldn’t be a very productive use of my time-out, so of course I did more analysis. First of all, it’s really hard for Black to decline the pawn because White’s threats rapidly become overwhelming. Shredder played 28. … Nxf5 first. If 28. … hg I would have played 29. Bh3!, very much like the game. Note that I do not want to exchange pawns on g5, because that would allow Black’s pieces to mobilize.

I played 29. ef, of course, and Shredder took the sacrifice with 29. … hg. Now comes the second most important move of the attack (which, unfortunately, I just gave away with my last note.)

checkers 2Position after 29. … hg. White to move.

FEN: r2b1rk1/1pq2ppn/p2p4/P1pPpPp1/R6P/1P6/2PB1PBK/3Q2R1 w – - 0 30

30. Bh3! …

I think I might have played the wrong move here if I had not taken my time-out. So many of us would play the “automatic recapture” 30. hg? But this would be a mistake because it allows Black to  play 30. … Bxg5 and start trading defenders for attackers. Another way to look at is that I solve Black’s two worst problems for him — I let his bishop on d8 and knight on h7 get into the game.

With the text move I more or less force Black to play … f6, hemming in both the knight and the bishop. The alternatives look even worse; 30. … gh allows 31. Bh6!, while on other moves, White regains his pawn with hg and gets a decisive attack on the h-file with Qh5 and Rh4.

30. … f6

Now I once again had two tempting options. The most swashbuckling idea is 31. hg fg 32. f6!?, sacrificing a second pawn to open up the bishop’s path to e6.

But before you start swashing and buckling, ask yourself if it really makes sense. Do I have to sacrifice a second pawn to activate my bishop? Are there other ways? Also, this idea starts to allow Black’s bishop and knight to have a purpose in life again.

There is another way to activate the bishop, and that brings us to the title of this post: checkers, anyone? I am going to move my bishop right up the board as if it were a checker: g2-h3-g4-h5-g6! And there is not a thing that Black can do about it.

31. Bg4! Qf7 32. Be3?! …

It turns out that this was unnecessarily cautious: the move 32. Bh5! wins by force. After 32. … Qxd5 33. Bg6 Rf7 (Black’s best try, according to the computer) 34. Qh5!! has two beautiful points. First, if Black takes the bishop with 34. … Qxd2, then 35. Bxf7+ forces mate. A key point is that Black cannot achieve a perpetual after an eventual … Qxf2+ Rg2, because White’s rook on a4 controls both checking square, h4 and f4. Isn’t that neat? The second beautiful point is that 34. … Nf8 is answered by 35. c4! Black’s queen has nowhere to go that would defend f7!

Unfortunately I missed both of these tactical tricks, and I couldn’t convince myself that the bishop sacrifice was actually justified. So I calmly defended my weaknesses.

32. … gh??

After this it’s an easy win for White. Black should have played 32. … g6, fighting for the light squares. I think White is still much better after 33. fg Qxg6 34. Be6+ Kh8 35. f4! and a blizzard of White pieces will descend on Black’s kingside. But there would still be work to be done, and a computer might be able to defend Black’s position. (It’s very unlikely that a human would.)

checkers 3Position after 32. … gh. White to move.

FEN: r2b1rk1/1p3qpn/p2p1p2/P1pPpP2/R5Bp/1P2B3/2P2P1K/3Q2R1 w – - 0 33

Now back to the game. Even with two extra pawns, Black is powerless to resist White’s slow-motion ”checkers attack.”

33. Bh5! Qe7 34. Bg6 e4 35. Qh5 Ng5 36. Bxg5 Qe5+ 37. Kh1 Black resigns.

This game shows really clearly the importance of asking yourself, “What are my worst pieces?” and also, “What are my opponent’s worst pieces?” White’s whole strategy revolves around making his problem pieces (the rook on a4 and the light-squared bishop) useful, while hemming in Black’s problem pieces (the dark-squared bishop and the knight on h7). Even when White had chances to open lines on the kingside — something one usually wants to do when attacking — I refrained from doing so because the strategic value of keeping Black’s problem pieces out of action was paramount.

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Yesterday I watched the PRO Chess League for the first time since week 2. (By the way, I finally found out that PRO is an abbreviation for Professional Rapid Online. That’s why it is obnoxiously capitalized all the time.)

Naturally, I jinxed the team I was rooting for, the San Jose Hackers. In a match where almost nothing went right, they lost to the Webster Windmills, 9½-6½. Through three rounds it was fairly close, with round-by-round scores of 2-2, 1½-2½, and 2-2, but because Webster had draw odds, San Jose needed to win the last round 3-1. Instead they lost 3-1, and thus their season ended.

In the other match that was going on at the same time, the St. Louis Arch Bishops, headed by Wesley So, squeaked by San Diego by a score of 8½-7½. They were aided greatly by So’s 4-0 result, which as I’ll show you below was somewhat miraculous.

So the two St. Louis teams beat the two California teams, and next week’s championship of the Pacific Division will take place on the banks of the Mississippi instead of the shores of the Pacific. But in the age of the Internet, does physical location matter any more? After all, one of the San Jose players was logging in from Azerbaijan, where the closest water is the Caspian Sea.

In the other three division championships next week, we’ll have Norway against Gorky, Montreal against Buenos Aires, and Marseilles against Stockholm.

The commentary by Alex Yermolinsky and David Pruess on last night’s matches was entertaining, as always. The chess was, well, interesting. During the roughly 45 minutes when I was watching, there were several amazing turns of fortune that unfortunately had more to do with blunders than brilliancies.

The first thing we found out was that you can throw endgame theory away when there are only a few seconds left on the clock. We saw a K+R+N versus K+R endgame and a K+R+B versus K+R endgame only a few minutes apart, and in both cases the stronger side won even though the endgames are well-known to be draws.

First, GM Ioan-Cristian Chirila (White) for San Jose and GM Vasil Durarbayli (Black) for Webster reached the following position.

march9-1Black to move.

FEN: 8/8/8/8/8/1K6/3RN3/1k3r2 b – - 0 1

Earlier Durarbayli had been in fine shape, but somehow he let his rook get too passive and drifted into, as Yermolinsky said, the “only winning position” for White in this endgame. If Black’s rook were on the eighth rank instead of the first, he would be able to harass White’s king with 1. … Rb8+ and there would be no win for White. But in the game, Black is in a mating net and lost after 1. … Kh1 2. Ra2+ Kb1 3. Nc3+ Kc1 4. Rc2 mate.

But the worst was yet to come. Ten minutes later, Michael Brown (White), playing for St. Louis, reached the following position against Varuzhan Akobyan (Black), playing for San Diego.

march9-2White to move.

FEN: 8/8/7K/R7/4bk2/8/8/6r1 w – - 0 1

Yermolinsky said that in the old days, one seldom even saw the K+R+B versus K+R endgame being played out. Grandmasters just assumed that the defender knew the several drawing techniques, and they would offer a draw. But in the era of Fischer clocks and sudden-death time controls, those gentlemanly ways have changed forever. The endgame usually comes up when one or both players have only a few seconds left per move, and very often the rook and bishop win, even at the GM level.

The position shown is drawn with correct play, but what happened was a comedy of errors that left poor Yermolinsky at a loss for words. Brown played 1. Ra4?, which loses. The correct move is not hard to find: you just have to defend Black’s main threat, which is the check on g6. So 1. Ra6 should draw. Also, the computer points out another cool drawing resource: 1. Rg5!, when the rook can’t be taken due to stalemate. This drives Black’s rook right off the seventh rank and forces some regrouping. A nice resource to know about.

Akobian played 1. … Rg6+ 2. Kh5 (forced). As Yermolinsky pointed out, 2. … Rb6 wins here. White’s rook has to stay on the fourth rank to prevent … Bf3+, and the king cannot move at all. So after 3. Rc4 Rb1, White’s only way out of mate is 4. Kh6, but now 4. … Rb7 forces mate.

If you have to choose a losing position for White, it’s actually better to have the Philidor position, with the king on h4. The win in that position demands considerably more subtlety from Black. The reason is that White can defend checks on the h-file from either side, putting his rook on the fifth rank to stop checks from above or on the third rank to stop checks from below.

Now it was Akobian’s turn to blunder with 2. … Rg8? This leads to something called the Szen position, a known draw, after 3. Ra6. But not known to Brown — or if he did know it, it went clear out of his head with only seconds left. 

Brown played 3. Kh6? Rg6+ 4. Kh5. Given a second chance to play … Rb6, Akobian whiffed again with 4. … Rg7? This time, Brown correctly played 5. Ra6, reaching the Szen position. But his joy was short-lived! Akobian played 5. … Rc7 and Brown now played the comical 6. Kh6???, walking into mate-in-one with 6. … Rh7 mate!

After the Brown-Akobian fiasco was done, Pruess apologized to Yermo on behalf of American chess: “Alex can’t handle how bad we are at endgames in the U.S.” Yermolinsky said, addressing all young American players, “Can’t you find two hours away from your [opening] databases and study this endgame so that you don’t embarrass yourself?”

Ironically, the “entertaining” style of chess favored by the PRO Chess League probably discourages true professionalism. There is less incentive to learn to play these highly theoretical endgames right, when you know they will probably be decided by a terrible blunder.

Sandwiched between these two endgames was a third miraculous save or tragic opportunity missed, depending on how you look at it.

march9-3White to move.

8/p3r1kp/1pQ2p2/6p1/4nPP1/P6P/1P4K1/8 w – - 0 1

Joshua Sheng (White) is playing for San Diego against Wesley So (Black). Sheng is the fourth board, a bona fide millennial, born in the year 2000 and rated 2375. Wesley So needs no introduction; he has simply been the most dominant player in the world over the last half year. But in this game, Sheng has So on the ropes, and is playing what could be the game of his young career.

Yermolinsky was explaining the winning strategy. First White should grab as much space as he can with 1. f5, and push his a-pawn to a5. Then he should play Kf3 and threaten to trade into a winning K+P endgame. I’m not quite clear on the last part … but if Yermo says so, there must be some way to do it.

Instead Sheng played 1. h4 gf 2. Kf3 Nc5. It seems as if White is making progress, but So has a surprise for him. 3. Kxf4 Ne3+ 4. Kg3 Re3+ 5. Kg2 Re2+. It’s perpetual check! White has no way to get away from Re1+, Re2+, and Re3+. Unless, of course, he plays 6. Kf3??, which is what Sheng did. So said “Thank you!” and played 6. … Ne5+, forking the king and queen.

Wow. In the space of 6 moves, So went from possibly losing (or at least facing a long hard defense), to an ingenious draw on the spot, to a win! As Yermolinsky said, that’s the kind of year he’s been having.

Some lessons from last night’s proceedings –

For adults, don’t underestimate the kids.

For kids, don’t underestimate the importance of endgames.

For all players, a knight in time trouble is worth double. (This is my revision of the proverb “A knight on the rim is dim.”) In a time scramble, with lots of pieces on the board, knights can be worth as much as rooks, because of their ability to fork other pieces combined with humans’ inability to spot those forks.

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PRO Chess League Week 2 Playoffs

March 8, 2017

Second round of the playoffs for the PRO Chess League. The first week (which I didn’t watch) must have been incredibly exciting, with none of the matches decided by more than 9½-6½. The San Jose Hackers, our curious mix of local and Azerbaijani talent, pulled off an exciting upset. As the #6 seed, they defeated […]

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An Honor to Have Played You

March 4, 2017

Yesterday I found out on Facebook that Walter Shipman had died. I guess it’s not too much of a surprise, as he was 87 years old, but he is one of those few people who seem determined to keep on going forever. Somehow that plan never seems to work, but he gave it a good […]

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Taking Your Time

March 2, 2017

Here’s a position that I got to against the computer. What do you think about it? What is White’s plan? Should he attack on the kingside or the queenside or the center? Should he go fast or go slow? Position after 14. … b5. White to move. FEN: r4rk1/2pqbpp1/p1n1p2p/1p1nP3/3PN3/2PQ1N2/PP1B2PP/3R1RK1 w – – 0 15 Shredder […]

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PRO Chess League Regular Season Complete

February 23, 2017

Wow, that was fast! It seems like just yesterday that I was writing a post about the first week of the PRO Chess League. Now the season is already over! That’s because it was only seven weeks long. Next week the playoffs will begin, and for people who haven’t been paying attention previously, this might […]

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Alternative Chess Facts. Plus, Reality TV!

February 13, 2017

In honor of our new “alternative facts” universe, I decided to delete my chess rating against Shredder (the computer program) and start over with no rating. After 925 games against it, I was unsatisfied with the fact that my rating had gone below 2000. It just wasn’t right! The alternative fact is that my rating […]

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“The Edge of the Truth” (Computer go and chess)

February 5, 2017

Last year I wrote a couple posts about AlphaGo, the computer go program developed by a team at Google that beat Lee Sedol (one of the world’s top players), 4-1, in a five-game match. If you’ve forgotten, you can read my post-match thoughts here. For several months nothing more was heard about the program, but […]

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My Worst Game Ever Against the Computer

February 3, 2017

Since my last post was about my best game (possibly) against the computer, fairness requires that I now show you my worst game, which I played yesterday. As ghastly as it is, there is still a fascinating train-wreck-in-slow-motion beauty to it. Shredder — Dana Mackenzie (40 moves/10 minutes) 1. e4 e5 2. Nc3 Nf6 3. […]

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Happy Halloween … Oops, Wrong Time of Year

January 18, 2017

Yesterday I wasted a ton of time playing against Shredder on my computer, and losing game after game… Finally I “dumbed the computer down” to a rating of 1977 just so that I would have a chance to win. And what do you know? I got a chance to play probably my nicest combination ever […]

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