Saturday, December 3, 2011

Pawn Tension part 1 (a wee lesson)

Well, I've played a lot of chess recently, and I seem to have a lot of it bubbling out of me, so hopefully this is the start of some more frequent posts ("more frequent" being a standard that is not hard to exceed). However, I do have a lot of other stuff bubbling out of me also, so we'll see which upwellings win the battle for my time.

This post (and hopefully a related one to follow) are explorations of the issues of pawn tension. It’s funny the way sometimes you see something basic in chess and then you start seeing it all over. I played a friendly game with a co-worker yesterday, and afterwards he asked me where he went wrong. I drew his attention to this position:
1. d4 d5 2. Nf3 Nf6 3. e3 Bf5 4. c4 c6 5. Bd3 Bxd3 6. Qxd3 e6


At this point, White pushed his c-pawn another square forward, which is something you should never, ever do. In fact, my computer Fritz’s evaluation of the position instantly goes from completely equal in the diagram to .4 pawns advantage for Black after White pushes the c-pawn.

The main concept here is pawn tension. In the diagram, there is tension between the black pawn at d5 and the white pawn at c4, which are mutually attacking each other. This means that Black can’t take action in the center without taking into account what might happen if White cashes in on the tension by capturing on d5. By pushing on past, White gets rid of the tension, thus giving Black a free hand for his own operations. In fact, Fritz’s preferred method of exploiting the push to c5 is for Black to play b6, immediately re-establishing pawn tension on a pair of squares that White has less control over:


This shows another reason why the push of the c-pawn is bad: it makes White’s bishop a worse piece. At this point, all of White’s center pawns are on dark squares, hemming in his remaining bishop. This is called a “bad bishop”. By contrast Black has a “good” bishop: its pawns are on squares of the opposite color. Perhaps White pushed the c-pawn in part to restrict the action of Black’s bishop, but you can see that this “restraining” pawn has become a target. In a way, the overall dynamic of this contrast is the same: White’s bad bishop can’t attack Black pawns (which are on the other color) so Black’s hand is free to do things like attacking pawns with his bishop.

In the actual game, after a few more developing moves,


Black got to play 12…e5. If Black had still needed to consider the consequences of a capture cxd4, this would have needed a whole lot more calculation. As it was, I just needed to see that there’s a potential pawn fork if the e-pawn continues forward; and after an exchange on e5, the c-pawn may also be vulnerable. After a few more exchanges in the center,


I got to play my knight to c4 (the square that White refused to contest at the very beginning), attacking both of White’s minor pieces. After 19…Nc4 20.Nb1 cxb5 21.Rxd5 b4 22.Bc1 Rfd8 I exchanged all the rooks on the d-file and my queenside pawns made a touchdown – precisely on the side of the board where White had originally advanced his own pawns.

After the game, I told my friend that his strategy had been discredited in the 1880s. I was thinking of a couple of games from the world championship match between Steinitz and Zukertort, and when I went and looked them up, it was clear why I associated them with this sort of pawn-play. They’re very cool games:

Johannes Hermann Zukertort - Wilhelm Steinitz
World Championship Match game 1, 1886

1.d4 d5 2.c4 c6 3.e3 Bf5 4.Nc3 e6 5.Nf3 Nd7 6.a3 Bd6


Look familiar? White now pushes he c-pawn forward; and on the next move, Black achieves the …e5 push
7.c5 Bc7 8.b4 e5


As in our stem game, White’s Bc1 is colossally “bad”, and Black is in control of the central tension. Black’s Bf5 is also bad theoretically; but since it’s outside the chain of black pawns, it’s a much better piece than White’s QB.
9.Be2 Ngf6 10.Bb2 e4 11.Nd2 h5 12.h3 Nf8 13.a4 Ng6 14.b5


Over the next past moves, Black has brought his knights over to the kingside and killed the pawn tension in the center, thus making sure that nothing significant is happening anywhere on the board except the sector where he plans to attack. He loved maneuvers like his Nf8-g6 here, building up a slow attack with his king still in the center. Now the knight continues his mission:
14…Nh4
The available ways of defending the g-pawn all involve some sort of positional concession, so Zukertort just pushes it, and then…
15.g3 Ng2+!? 16.Kf1 Nxe3+ 17.fxe3 Bxg3 18.Kg2 Bc7


Steinitz has give up his charging knight for two pawns in order to expose the White king. Because the rest of the board is all locked up, he can continue feeding pieces over there without much else happening. White has to find some really precise defensive moves to neutralize this very nebulous attacking setup, and Zukertort isn’t up to the task:
19.Qg1?

He’s getting the queen out of the way so that his king can run back to the center (and hopefully even the queenside) but this is the wrong way to do it. He should move the queen to f1, overprotecting the h3 pawn and gaining a tempo by attacking the undefended Bf5. After the bishop retreats, White can play Kf2 and the king will continue his run to safety. Then the game will go on; Fritz thinks that White has a slight advantage, but there isn't any clear plan on the board for him to undertake.

In response to Qf1, Black must retreat the Bf5, since after
19.Qf1 Qd7? 20.bxc6 bxc6 21.Nb5!


White is suddenly doing very worthwhile things on the queenside. Black can’t capture the knight since the bishop recapture pins his queen. And Black’s queen can’t defend both bishops at the same time, so after 21…Be6 22.Nd6+! Black doesn’t want to leave the knight sitting there in the heart of his position, blocking the attacking Bc7; but after 22…Bxd6 23.cxd6 Qxd6 24.Ba3! suddenly White’s “bad” bishop is very actively placed, and after 24…Qd7 25.Kf2 the White king continues his trek to safety.
As it is, after
19.Qg1? Rh6 (threatening to win the queen with Rg6+) 20.Kf1 Rg6 21.Qf2 Qd7 22.bxc6 bxc6


with Black’s rook already in attacking position at g6, White has no time for Nb5 here, because after 23.Nb5 Bxh3+ 24.Ke1 Bg3 White’s queen is pinned and lost. Black will just move his king in response to Nd6+ here. So White must defend g3 with another piece:
23.Rg1 Bxh3+ 24.Ke1 Ng4 25.Bxg4 Bxg4 26.Ne2 Qe7 27.Nf4 Rh6 28.Bc3 g5 29.Ne2 Rf6 30.Qg2 Rf3!


Steinitz must have enjoyed making this move: he always did say that you should attack a pawn chain at its base. If you compare this diagram and the previous one, you’ll see that Steinitz’s pieces have been moving forward while White’s are basically just shuffling around. That trend will continue.
31.Nf1
If 31.Nxf3 exf3 32.Qf2 fxe2 then Black has just gotten two knights for his rook; factoring in the knight that he originally sacrificed, and the pawns he’s picked up along the way, that leaves him with three pawns for the exchange, a massive material advantage.
31...Rb8
Steinitz adds insult to injury by taking control of the open file in White’s preferred sector of the board.
32.Kd2 f5 33.a5 f4 34.Rh1 Qf7


Black has just kept building up. It’s now impossible for White to avoid the loss of major material.
35.Re1 fxe3+ 36.Nxe3 Rf2


The White queen’s only flight square is g1; but then Qf3 comes and the Ne2 falls, then the king behind it. So….
37.Qxf2 Qxf2 38.Nxg4 Bf4+ 39.Kc2 hxg4 40.Bd2 e3


This seems to have been a tremendous time scramble, but even so I think I would have been embarrassed into resigning at this point. Note, however, that Rh8+ doesn’t win Black’s rook, as it is protected by his bishop. Given what happens later, that might have been a good try, though.
41.Bc1 Qg2 42.Kc3 Kd7 43.Rh7+ Ke6 44.Rh6+ Kf5 45.Bxe3 Bxe3 46.Rf1+


Yes, apparently this really happened in a world championship game: White gives check with an unprotected rook next to the black queen, and Black doesn’t take it. One for the ages.
46…Bf4 0–1

Okay, this is enough for the moment; hopefully I’ll be posting the second Zukertort-Steinitz encounter and another relevant game anon.

Saturday, September 24, 2011

You gotta love it

This sort of victory is probably at least partially responsible for my poorer tournament results, but you’ve still gotta love it when something like this happens:

Shernoff-Count Mulningsvelin, FICS blitz 2011
I am giving my opponent the title of Count, because he generously did his best to make me look like Paul Morphy in that opera box...

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. f4 Qc7 7. Bd3 Nbd7 8. Nf3 b5 9. O-O b4 10. Ne2 Bb7 11. Ng3

We have a fairly normal Sicilian


11...Nc5 12. Qe1 a5 13. Bb5+ Bc6 14. Bxc6+ Qxc6 15. e5 dxe5 16. fxe5 Nfe4 17. Ng5 Nxg5 18. Bxg5 Ne6 19. Be3

It’s now an even more typical Sicilian in that Black has (a) no development (b) no presence in the center, but is still okay. But now Black goes crazy and starts grabbing pawns – not a recommended action when your opponent can bring all three major pieces to the center, where your king is.


19...Qxc2

I was anticipating 19... g6 20. Qf2 Nd8 and I wasn’t sure how to proceed. Fritz then makes the easily-findable moves 21. Bb6 Qe6 22. Ne4 Bh6 and awards White a clear advantage from opening up the queenside with 23. a3!
After Black's capture, I considered preserving my precious queenside pawns with 20.Rf2 and Qf1, with threats against f7 and b5, but I decided that my queen would be better off on d1, ready to come to f3 which is strong...

20. Rc1 Qxb2??
I didn’t give Black’s previous move a question mark because Fritz actually thinks it’s the best move! But that’s only because it follows up with 20... Qd3, keeping my queen off d1.
21. Qd1 Qxe5?
and here f3 is of course still a winning possibility; but Black’s kind capture on c2 has opened up a new diagonal for my queen:
22. Qa4+


22... Kd8 23. Rfd1+ Qd6 24. Bb6+ Nc7 25. Bxc7+
1-0

Thursday, August 11, 2011

Fourth of July games

For a few years now, my friend and neighbor Tom Panelas has been running a bank of chess boards at our local fourth of July shindig it the park down the street from where I live. This year, I showed up fairly early and ended up manning two boards for most of the afternoon, mostly against kids who were under 10 in age and under 1000 in playing strength. I did have one tremendously entertaining game, though, against Adam J, captain of the Wendell Philips High School chess team, and I wanted to share it because it’s become sort of a tradition for me to tremendously embarrass myself on the internet at least once a year.

But first I wanted to share a game against one of the few grown-ups to challenge me, just to show that I had some measure of general coherency during the afternoon. This game started off as a fairly normal English:

Grown-up - Shernoff [A20]
Nichols Park 4th of July, 04.07.2011
1.c4 e5 2.e3 f5 3.a3 Nf6 4.Nc3 g6 5.d3 Bg7 6.Nf3 Nc6 7.b4 0–0


After it was no longer an issue, I noticed that White could have taken my e-pawn after b4-b5 around here. Here, it doesn’t really work, because of 8.b5 Ne7 9.Nxe5 Ng4 and Black gets into trouble on the long diagonal. But he should definitely do it on the next move, or play Be2 and castle, because he ends up wasting too much time with these meaningless pawn moves on the queenside.
8.Bb2 d5 9.c5?!


Okay, I’ve got the big center, he isn’t castled but I am, ergo I should push a center pawn. The f-pawn is keeping a knight off e4 for me, so I think I’ll push the d-pawn.

9...d4 10.Qb3+ Kh8 11.exd4?! (better is 11.Ne2) 11...exd4!?

After 11...Nxd4 12.Nxd4 exd4 13.Ne2 Re8, Fritz awards me an advantage of .69 of a pawn, but this isn’t likely to result in the sort of game I want to play outdoors on a hot afternoon.

12.Nb5?

This looks natural and aggressive, but it’s wrong, because the knight doesn’t have a safe retreat. After 12.Ne2, Fritz rates the position equal, as it doesn’t trust my ability to hold the pawn at d4 after the upcoming b4-b5 push.

12...Re8+ 13.Be2


13...Nd5
and again, this is an overplay, but I was pretty sure he’d grab the d-pawn. Better is 13...Nh5, when I’m holding the d4 pawn solidly and White can’t stop both Nf4 (with trouble for the Be2) and a6 (with trouble for the Nb5).

14.Nbxd4? (14.g3 is the only move) 14...Nf4


15.Nxc6
This is a natural move: White gets rid of his en-prise piece while attacking my queen, and is ready to exchange his Bb2 with check, thus preserving it from capture. However...

15...Rxe2+ 16.Kf1 Rxb2
Whoopsies!

17.Qxb2 17...Qxd3+ 0–1

Okay, on to the main show. It is essential to realize that I had just been playing for two or three hours against small children and my whole attitude was focused on playing quickly and grabbing material (the above game was played after this one). It took me a while to adjust when faced with a real player.

Adam J - Shernoff
Nichols Park 4th of July, 04.07.2011
1.h4


Oh! He’s one of those players. Wants to bring the rook out first. Well, I can cover h3 with my bishop.

1...d5 2.h5

Hmm. A new square for his rook. Well, I can cover that with my queen.

2...e5


3.h6
Man, he really wants to bring that rook out, doesn’t he? At this point, I’m not expecting the game to be very difficult.

3...Nxh6 4.Rh5 Nc6 5.Nf3 Bd6?!

I was just thinking in terms of sitting tight in the center without thinking too much and waiting for him to hang something. Fritz already wants me to start playing more constructively with moves like
5...e4, which I will follow up with other moves like Qf6 (if 6.Ne5 then 6...Nxe5 7.Rxe5 Be6 first), Bc5, and 0-0-0. Black dominates the center and is efficiently developed.

6.Nc3 Be6 7.a4 Qf6 8.a5


8...a6?

Stupid, stupid, stupid. I actually thought “Well, if I don’t fix the pawn here, he’ll just push it another square and I’ll have to lose a tempo playing b6 anyway.” Of course if that happens then – Hello! – he’ll have lost another tempo ALSO, pushing the pawn that extra square.
Sadly for the future quality of this game, Adam is playing badly enough (with this “push both rook pawns” garbage) to convince me that he’ll soon tank, but without actually playing badly enough to instantly lose. Well, that’s not true – White had a fairly crushing line here if he’d just started to think positively and targeted f2, instead of just waiting for a blunder:
After 8...e4


9.Ng5 (9.Ng1 Qxf2+! 10.Kxf2 Ng4+ and Bg3#) 9...Ng4 and white is forced to take twice on e4 with his knights, as 10.Nh3 is met by 10...Nxf2 11.Nxf2 Bg3. Sadly, this line remained unplayed.
Instead,

I realized that I had to start playing constructively here, and decided to cleverly play Nb4 and Qg6 here, threatening the brutal Nxc2+ and the Rh5. Unfortunately, I violated basic chess precepts like “Hey, he gets to make moves also” and “BTW, you should pay attention to what those are.”

8...a6 9.Ra4 Nb4 10.d4


10...Qg6?

By now I really should react to him in the center and take the d-pawn, but then he takes back with his knight which then defends c2 and I’d have to think of something new to do and do a bunch more calculating, and it was too hot for that, plus the little kid on my other board kept yelling at me to move more quickly, and...

11.dxe5 Qxh5 12.exd6

Ooops! Now my Nb4 is hanging, and I react badly...


12...Nc6? (12...c5!) 13.dxc7 0–0


Now I figure I’ll just round up the c7 pawn and crush him... somehow. In fact, Fritz calls this position equal, a measure of how badly I’ve played over the last few moves. And as often happens when you’ve blown an advantage but don’t realize it, I get frustrated trying to find good lines that aren’t there anymore, and make matters worse. Much, much worse.

14.Qd3 Rac8 15.Ng5


Hey! He’s threatening mate! How’d he do that?

15...Nf5??


Way dumb. I was concerned about not only blocking the mate, but getting my knight back into play and having my queen defend against the mate so the knight could move again. I just didn’t calculate. After 15...Bf5 16.Qxd5 Rxc7 Black is doing all right again.

16.Nxd5??

16.g4, forking my queen and knight, is, umm, much stronger.

16...Ne5??????

There’s a game against Portisch where Vlastimil Hort says “My hand should be cut off for making this move.” This is that kind of move. It’s wrong on just so many levels.
First of all, I saw perfectly well that he would just play Qe4 and my knight can’t be maintained on that square, so he’ll get to capture on e6. Second, since in my pride I want to pretend that I moved the knight to e5 for a reason, so I won’t retreat it to c6, which is in fact its best square.

17.Qe4 Ng6 18.Nxe6 fxe6 19.Qxe6+ Kh8 20.Rc4


Hey! Did I mention that my knight should really be on c6? White now has a colossal advantage. Among his threats is Nb6. I play yet another move without thinking, simply making stupid threats by reflex under the theory that eventually he’ll just screw up on his own:

20... Rfe8?? 21.Qxe8+! Rxe8 22.c8Q


Hey! Did I mention that my knight should be on c6?
Now I really had to do some thinking. I’m down a piece and a pawn, and I’m going to lose more pawns on the queenside because of his back-rank threats.

22...Nge7!?

Fritz wants me to fork immediately with 22...Nd6 23.Qc5 (23.Qd7 Qxd5) 23...Nxc4 24.Qxc4. I regarded this as insufficient (Fritz rates White as ahead by 3.2 pawns) and went for a potentially bigger regain of material.

23.Qxb7 Nd6 24.Qxa6

Did I ever mention that it was stupid of me to push this pawn to a6? Did I?


24...Nxc4 25.Nf4??

Adam sees that if he recaptures on c4, I’ll capture on d5. But that just means that he should put that hanging piece on d5 to work first, and capture 25.Nxe7! Then there’s really no hope for me. Now I’m still nominally behind in material, but I have chances because his development is so poor. On the other hand, I still have back-rank problems and he’s got an a-pawn that’s pretty close to queening. Still not any easy game for either player.

25...Qc5

He needs to move his e-pawn one or two spaces here and get his bishops out. But unfortunately I think he decided that defending the a-pawn was important. It is, I suppose, but not as much as his development. And if he can get the queens off along with that, so much the better: 26.e3 Nxa5 27.Qb5, hitting e8, and his remaining queenside pawns will roll me up.


26.Bd2?? Nxb2?

26...Nxd2 27.Kxd2 Qb4+ would have won the Nf4, but who’s calculating when I can just enter his position like this?


27.f3?

This is a pretty awful move, but it’s actually really difficult to play White’s position now. After 27.Nd3 Qxc2 28.Nxb2 Qxb2 29.e3 Qa1+, White loses coordination. So the very best move is 27.c3!!, so that White can play Nd3 on the next move without losing the c-pawn. Then 27. c3 Nd5 28.Nd3 Nxd3 29.Qxd3 and Fritz calls this position equal. These two are by far White’s best lines, which shows how careful he has to be here.

27...Qxc2 28.Qb5 (Maybe I’ll drop the rook) Rd8 29.Bb4 (Maybe I’ll drop the knight) Nf5
Now he’s making it obvious, but Adam’s actually been playing little one-mover threats for a long time now. It’s almost as if he’s caught my disease from earlier in the game.
30.a6 Qc1+ 31.Kf2 Nd1+
Yes, I actually missed a mate with 31...Qe3+ 32.Ke1 Rd1
32.Kg1 Nde3 33.Qb6


Okay, showtime! I’ve got one hell of a bind, and the Bf1 is evaporating, but my Rd8 is also hanging with mate, and I don’t want to put it on g8 and have him try to conjure some smothered mate (or Ng6+ & Q-h-file mate) or queening his a-pawn... I wanted it to be over, quickly and permanently. So I enlisted the help of Susan, the vastly underrated little girl on the other board (“Hey! That’s cheating!” said Adam) to check my calculations as I finished things off with checks.

33...Qxf1+ 34.Kh2 Ng4+!


Susan had not anticipated this, but she felt very proud of herself for being able to calculate that on 35.fxg4+ Qxf4+, 36. Kh3 Qg3 is mate, and if the white king steps back instead (before or after 26.g3 Qxg3+) then Rd1 mates. So Adam didn’t take the knight, but after

35.Kh3 Nf2+

Susan was shocked to discover that 36.Kh2 is met by Qh1#, so Adam played
36.Qxf2
and the rest of the game wasn’t that difficult.

What a fourth of July!
More games from the Skokie tournament that I won coming in a bit...

Thursday, July 28, 2011

May tournament round 1

Hello, everyone!

I’ve finally gotten a few moments to start answering the questions in the quiz I posed a while back.

Actually, I’m going to do that by going through my games from the May tournament that I won. There’s a surprising amount of stuff in some fairly simple-looking games. This is the first game in that tournament, and the answer to the first quiz position.

But first another little quiz:
White has given check, seeking compensation for his pawn minus in his bishop pair and better development:


There are themes of Re7+ if the king moves to the second rank, and Kd8 is met by Nxg7 followed by (...Rf8, Nh5) Bxf6+. What about Kf8, which avoids these problems?


Okay, here's the game:

Vytas Vytsauskas - Leon Shernoff [A27] Skokie G/90, 5.6.2011

after a mutually misplayed opening, we reached this position. I was definitely playing myself back into shape in this first-round game, and for some reason couldn’t see any difference between the various Nc6 moves! I knew I was going to play …d6 and …b6 soon and then the knight(s) dance to those squares and onwards; I wasn’t seeing any difference in where they went first. Luckily, at the last minute my hand reached out and threw the knight onto a5 without any conscious intervention on my part.

Also part of the "playing myself back into shape" thing: I thought I was okay at this point, but it turns out I’m definitely not!


9… Na5 10.Qxe7+ Kxe7 11.Bd3 h6


Black is playing very slowly and for the greatest possible advantage: I see that my knights can kick the butt of White’s doubled pawn complex, so I don’t want him to be able to exchange one of them with Bg5.

The course of the game will show what I was aiming for, since it gets implemented pretty much without opposition. It may seem a little strange here, but White should have taken a bunch of moves to exchange his bishop and inflict a similar weakness on Black: 12.Ba3+-b4xa5 was best. Fritz then gives White an advantage of almost a pawn.

12.0–0? b6 13.Nd4?!

Similarly, even here, better is 13.Re1+ Kf8 14.Ba3+ d6 15.Bb4 Nb7 and suddenly White’s space advantage is actually useful and his pieces aren’t tied down to his weaknesses like they end up in the game.

13… Ba6 14.Nf5+

At first, I was worried about 14.Nb5, because I consider Vito a better calculater than I am; and there’s lots of stuff that could go wrong for Black after this move. But 14…Bxb5 15.Re1+ Kd8 16.cxb5 Nxd5 is safe enough.

14...Kf8 15.Ne3 d6


16.Bd2?!

Again, the bishop should go to a3 to exchange off the first knight that appears on c5. On d2 it is just in the way, and something of a target.

16…Nd7


How should White respond to this move? It threatens Ne5, irrevocably winning a pawn, and thus provokes 17.f4. But it’s not hard to see that White will lose a pawn soon anyway, so maybe it was better to just try and get active and avoid making this new weakness. After all, once Black takes on c4, that opens things up a bit for White’s bishops. Fritz has White only down half a pawn after
17.Rfe1 Ne5 18.Bf1 Nexc4 19.Rad1


which is way better than the game continuation.

In fact, if Black takes on c4 with the bishop to avoid the pin:
18...Bxc4 19.Nxc4 Naxc4 20.Bc1 g5 21.Re4 Na5 22.f4


Fritz calls this position equal, though I respectfully think that the extra pawn is still a pawn here. Granted, neither of these is a position that White wants to achieve out of the opening; but it’s loads better than what actually happens to him.

The question of whether White can/should just shed a pawn early and try to get compensation through the opening of the position for his bishops will keep recurring over the next several moves.

17.f4 Nc5 18.Be2 Re8


This is the position that I put up as a quiz last month. The question is how to respond to Black’s pressure on the e-file. In fact, my main concern here was how to get my Rh8 into action. If I play …g6 (instead of Re8), intending …Kg7, then he plays f5, and suddenly it looks like his kingside pieces are doing something real. Likewise, after …f6 he has Bh5, and I don’t want this to happen either. I could walk my king to h7; but that’s way lame considering how much time it takes and considering that since we’re on the verge of an ending, the king will soon have to walk all the way back to the center. So I decided to probe by developing the other rook, and see if I could develop my pieces this way.

19.Rf3?!

After this, Black achieves a total bind unhindered. I thought that White had to try 19.Kf2, protecting both pieces on the e-file, as after the game move I have 19…f5, solving my development problems and fixing the weak Pf4.

Well, it turns out that 19.Kf2 loses a pawn to Ne4xc3 and Rxe3 – in fact this is a general threat of 18…Re8 (so Fritz in fact also prefers 19.Rf3). I hadn’t noticed this at all during the game (like I said, I was definitely playing myself back into shape at this point) because I was mainly concerned with how to get the Rh8 into play. However, shedding a pawn is not necessarily bad for White if it opens up things for his bishops and gets his pieces active. There are two ways to attempt this: 19.Kf2 and 19.Rae1.

As Todd pointed out, 19.Kf2 has the flaw of not developing further, while uncastling the king. On the other hand, it turns out to allow Bxa5 (finally!), which almost balances out these flaws:
19.Kf2 Ne4+ (19...Re4!? ×f4, c4) 20.Ke1 Nxc3 21.Bxc3 Rxe3 22.Bxa5 Bxc4


(looks scary, but…) 23.Rf2 bxa5 24.Kd2 Rxe2 25.Rxe2 Bxe2 26.Kxe2 with a rook and pawn ending that most of us humans would consider quite blowable – Black has two extra pawns, but one them is doubled and isolated, and the other is backwards on an open file. Plus, White is about to activate his rook first.

Certainly, White’s chances are way better than in the game.

19.Rae1 looks much more constructive, and (but?) carries with it the possibility (risk?) of much more active/dynamic/complex play to justify the additional material sacrifice. In short, this is the line to go for if you think White should be pursuing radical remedies here:

19…Ne4 20.Bc1 Nxc3 21.Bd3


and now Todd gives
21...Ne4 22.Bb2 Nf6 23.g4
when White has full counterplay. Fritz plays more dynamically for Black, giving 22...Nc5 (instead of Nf6) 23.Nf5 f6 24.Rxe8+ Kxe8 25.Re1+


and awards Black an advantage of a third of a pawn, but the possibilities here of Re7, or (…Kd8) Nxg7-h5 render this fairly meaningless in human terms.

Quiz Answer!
The move that best avoids these possibilities, 25…Kf8??, sadly runs into 26.Nxd6! with back-rank awfulness (26...cxd6 27.Bg6).

In any case, the two bishops and the undeveloped Rh8 are really showcased in these lines. Black’s extra pawn is fairly meaningless at the moment.

However, Black has a more dynamic possibility himself, grabbing another pawn with 21…Nxa2 (instead of 21…Ne4), and the black knights start to dance on the queenside:


21…Nxa2 22.Ba3 (22.Bd2 Nb3) 22...Nc3 23.Bb4 Na4


Finally, the white bishop has reached b4, but it’s not enough. White has two possibilities, and both are fairly messy, but they also seem fairly won for Black (given enough time):
24.Bc2 Nc5 25.Bxa5 bxa5 26.Kf2


and White is ready to play 27.Ra1, but this doesn’t seem like enough.

The other line is


24.Nf5 Nc5 25.Rxe8+ Kxe8 26.Re1+ Kd8 27.Bf1 Bxc4 (27...g6 28.Nd4) 28.Bxa5 Bxf1 29.Kxf1 bxa5 and White is down three pawns at the moment.


After taking on g7, Fritz rates Black's advantage at only 1.3, which again is much less than in the game, but still should really be losing, especially as it's much harder for White to get at Black's queenside pawns in this line.

At any rate, we can now appreciate the complications that White could have spawned, instead of the continuation in the game where Black just gets to sit on him without worries:


19.Rf3?! f5! 20.Kf1 g6

Now I have a choice of developing my kingside with Kf/g7 and Re8, or Rh7-e7.
Fritz prefers to swoop in immediately with

20...Re4 21.Re1 Bxc4 22.Nxc4 Nxc4 23.Bc1 b5


which indeed looks quite dominating. But it only gets this far by rejecting (20...Re4 ) 21.Nxf5 Nxc4 22.Bxc4 Bxc4+ 23.Kg1 Bxd5


when White has genuine activity, potentially meaningful pawn imbalances, and opposite colored bishops. To a human, this is much less attractive for Black than what happens in the game. Especially in a G/90 situation, the trouble-free situation is the one to go for.

Back to the game:


21.Rd1 Re4 22.Be1 Bxc4

White is ready to defend his c-pawn with Rd4, so Black needs to take.

Depending on your point of view, my move is either an inaccuracy or a clever trap. I wanted to exchange two pairs of minor pieces, which I can force by 22...Nxc4, but I didn't see that my Ba6 was defended, so thought I had to take with the bishop first.

23.Nxc4 Nxc4


24.Bxc4

All’s well that ends well: he decides to trade everything anyway. Fritz tries to keep the minors on, but then finds out that this loses more material (this would be the clever trap): 24.Rd4 Ne3+ 25.Kg1 (25.Kf2 Ng4+ 26.Kf1 Nxh2+) 25...Nxd5.

24...Rxc4


25.Rd4?
This is a big mistake, as now White can’t avoid the loss of another pawn via the following maneuver, and he’ll be left with an awful minor piece. Correct was
25.Bf2 Ne4 26.Bd4 Rh7
when White’s only one pawn down with a lousy position, and Black will have trouble making progress without allowing the exchange of his knight. As the game goes, White not only loses another pawn, his bishop is a huge albatross around his neck.

25...Rxd4 26.cxd4 Ne4 27.Ke2 Nf6 28.Kd3 Nxd5 29.Kc4 c6 30.a4 a5 31.h3 h5 32.Bd2 Kf7 33.g3 Re8 34.Kd3 Re4 35.Kc4


There has been none of the White counterplay we’ve seen in the earlier sidelines. Fritz awards Black a 3.6 pawn advantage, even though White is only two pawns down on the board and has the more centralized king.

Now Fritz wants Black to play 35...Nc7 (with the idea of c6-c5) 36.Rd3 d5+ 37.Kc3 h4 38.gxh4 Ne6 at which point it gives Black a four-pawn advantage. However, I stick to my ultra-solid style of cashing in:
35...Re2 36.Kd3 Rh2 37.h4 Rh1 38.Kc4 Rb1 39.Ra3


Now that my Rb1 is holding my one weak(ish) pawn on b6 (against Rb3), I can swing my knight to e4, causing White’s bishop a bit of embarrassment. I’m hoping for something like (magically move Black’s knight to e4 in the above diagram) Kd3 Rd1 Ra2, or Bc3 Rc1 where the bishop is pinned, and I get to exchange all the pieces, leaving me with a dead-won pawn ending. I like dead-won pawn endings. But even without that, the next order of business is N-f6-e4 and Ke6-d5.

Best for White is probably (39…Nf6) 40.Kd3 Ne4 41.Be3, but there’s no doubt about the outcome after I bring my king to d5. Instead, White blunders.

39...Nf6 40.Rb3?? d5+ 41.Kc3 Ne4+
0–1

because of …Rxb3 and Nxd2