Tomb Raider

The Tomb Raider franchise began in 1996 when game studio Core Design released under its parent company Eidos Interactive, a third-person 3D action adventure featuring acrobatic (and shapely) Lara Croft as the Tomb Raider navigating through traps. Since that time, the franchise has gone on to publish about fifteen game titles and inspire two movies starring Angelina Jolie. A reboot of the film franchise is in development with Alicia Vikander (from Ex Machina) in the title role.

I won a game last month that reminded me of the Tomb Raider. My opponent offered material for the possibility of trapping my queen. I stayed one step ahead of the traps and managed to escape with the material advantage intact. I'm playing Black. White's 20th move was 20.Qc2-e2, loosening the protection of the Nb3, to which I responded 20...Qc7-d7 threatening to capture the white pawn on a4 and having a follow-up threat against Nb3 for the next move. Notice that Black has a loose a7 pawn.

My opponent and I were both a little short on time, about 15 minutes to make 10 moves and reach move 30. Ideally, both sides could sink into 30-45 minute thinks and try to work out the next 8-12 plies with some level of certainty before making such committal moves. Barring that, I fell back on intuition that I could use the pawn exchanges at e4 and b4 and my well-placed rooks at c8 and d8 to aid my queen's escape. If the two white rooks came to a1 and b1, the bishop would have trouble discovering the attack of the b-rook because a1 was occupied and Bc1 allows simply Qxc3. If the minor pieces could not trap my queen, then I might be able to sac my queen for a rook, thereby gaining at least material parity. I also used a rough risk-reward calculation: if I took on a4, worst case scenario was that Ra1 forces my queen to retreat to d7 and then I would have to contend with Rxa7. So, sometimes, I used shorter variations than I really should have to substitute for calculated certainty. My opponent sweetened the reward by cutting off the protection of Bb2. 21.Nc2??

I knew that I was getting the a-pawn and at least positional play against a pair of awkward knights (if either knight goes to a1). If he tried to trap my queen with Ra1, I would get the Nb3 and tempo against the loose Bb2. So I took the bait and entered the tomb. 21...Qxa4 22.Ra1

Last chance to bail out with Qd7 Rxa7. No guts no glory. 22...Qxb3 23.Reb1

White is one move away from trapping the Black Queen with Ra3, but Black has several resources to delay that outcome. The most immediate is cxb4. This has the possibility of opening the c-file for the Black rook and it also temporarily prevents Ra3. However, White would almost certainly play Nxb4, keeping the c-file semi-closed. Another resource is dxe4, temporarily giving Black the potential of Qd5, but fxe4 leaves the queen trapped. I already began to see the possibility of a bailout sacrifice to get my queen out of trouble, but I wasn't sure it was going to work. So I went for the pawn exchanges to improve my rooks. 23...dxe4 24.fxe4

24...cxb4 25.Nxb4

A pause now that we're five moves closer to time control. I was annoyed at the weakness of my a7 pawn and the tempo that Rxa7 might get on my Bb7. Since I was already up a knight and a pawn, I calculated that 25...a5 26.Ra3 Qxa3 27.Bxa3 axb4 might be a bailout strategy. Do you see the other possibility of bailout yet? 25...a5 26.Ra3. White moved in to kill my queen.

Even though 26...Qxa3 27.Bxa3 axb4 28.Bxb4 carries the material advantage of queen (9) for rook and two knights (11), White's position seemed annoyingly consolidated. I couldn't see how I was going to organize my pieces for the next round of battle. With White's Nb4 under attack and both our time troubles becoming serious, I decided to play my ace in the hole. 26...Nd4!.

If he captures my queen with Rxb3, I capture his queen with check Nxe2+ with more even exchanges helping Black's endgame. If he captures my knight with cxd4, I capture his knight Qxb4 and get my queen away safely with the knight advantage. If he saves his queen, I save my queen with Qe6. My opponent let his time tick down to about 1 minute for 4 moves as he tried to work out this mess. He finally settled on 27.Qd2 Qe6.

At this point, I figured that White should trade knights and gain a protected passer at d5, e.g. 28.cxd4 axb4 29.d5. Another variation could have gone 28.Nc2 Nxc2 29.Rxc2. However, with his time trouble, White tried too hard to avoid exchanges and came up with a move that made his knight, bishop, and rook awkward. 28.Na2?

With the remaining time on my clock, I retreated while picking on the awkward rook. 28...Nb5 29.Ra4 Nd6 30.Qf2 Bc6. With a piece and a pawn down and the possibility of losing the rook, my opponent resigned. Black's most straightforward win goes 31.Ra3 Nb5 32.Ra4 Qb3 going back to the tomb to loot more treasure.

Repeater

About a year ago, I blogged about an ending involving the snare-like properties of Plants vs. Zombies Winter Melon. Funny enough, a friend who didn't know I like PvZ noticed and we compared notes on the Survival:Endless levels. Here is my setup, which got me to level 1000 before I quit.

Well, I managed to survive some of my own attempts to mentally defeat myself and I won the club championship for a second year in a row. I struggled through the qualifier, grabbing the sixth seed. Funny enough, all four past club champions ended up on one side of the 8-man bracket. I defeated two players that I beat in last year's championship, this time more quickly as they each lasted 3 games each instead of last year's 8- and 6-game matches. But the finals this year took 8 games. Adding in the 9-game qualifier, the road to the championship lasted 23 games this year; last year it took 24 games.

I could complain about the length of the club championship, but perhaps the blame would be misplaced. I lack the stamina to concentrate on chess for a whole weekend swiss. Right now, I'm taking a break from chess, hoping that my natural rhythms will bring me back to it in time for the club championship qualifier after the New Year.

For now, here is the retrospective on 2015's year in chess, especially benchmarked against last year's assessment

On the positive side:
• Played 35 rated regular games, about 33% less than last year (54).
• Had fun for the first 6 months.
• Pushed my peak rating up to 2133, 1 point higher than last year (2132), but slid back down to 2105.
• Won the club championship for a second time
• Contended for the state championship for the second time (semifinalist)
• Finished the year with a plus score against experts for the second time 8W-8D-6L
• Five of my games against strong players went into trappy lines I had prepared resulting in 3 wins, 2 draws

On the negative side:
• Many of my games - wins, losses, and draws - seemed to be decided on luck as opposed to good technique
• I didn't win any money, didn't finish at the top of any non-match tournaments, and felt too tired to play in weekend swisses

Fewer positives, but also fewer negatives. I'm debating whether I have enough motivation to contend for the championship again. But Plants versus Zombies also has a Threepeater plant...

Winter Melon

When I'm not playing chess, sometimes I play Plants versus Zombies. One of my favorite weapons to plant is the Winter Melon which not only causes splash damage, but it also slows down the zombies over a 3x3 area.

Recently, I almost gave away my copy of Chernev's Practical Chess Openings. But after my last endgame debacle, I went looking for a reference on rook versus two connected pawns and found it in Chernev's book. Perusing the beginning pages, I ran across some pawn endings that were far from trivial. In each of these three endgame studies, it is helpful to remember that the attacking king can be used like the Winter Melon to slow down the enemy pawn.

Practical Chess Endings #23
Grigoriev 1928

White to play and win

It should be clear after a little calculation that a pure pawn race leads to a draw. Even though White's pawn can queen with check, Black's pawn first reaches b3 and gains a tempo because of the check on White's king. e.g. 1.g4? b5 2.g5 b4 3.g6 b3+ 4.Kd2 b2 5.g7 b1Q 6.g8Q+ 7.Qb3=. Because of this, White embarks on a short walk with his king to c4, forcing Black to mirror the same short walk to a4. When Black's pawn checks the White king during its advance, White moves the king back toward c2 via d3. This forces Black to move his king back to a2. White then queens with check and wins. In the drawing line above, Black moves his king zero times to White's one time. In the following winning line, White and Black each move their kings four times before White queens with check.1.Kc3! Ka3 2.Kc4! Ka4 3.g4! b5+ 4.Kd3! b4 5.g5! b3 6.g6! b2 7.Kc2! Ka3 8.g7! Ka2 9.g8Q+! Ka3 10.Qb3#

Practical Chess Endings #24
Duras 1905

White to play and win

I have previously generalized that it is dangerous to step on a square that allows the opponent to queen with check, but in this study, that's the only move that wins. If 1.Kc4?, then Black steps in front of his own pawn 1...Kg6 or 1...Kg5 and can draw by hightailing it to b8, preventing White from queening. The key idea is to invest time moving the White king from c5 to f2. This forces Black to move his king to h2 where it will be checked by the new White queen. 1.Kc5! g5 2.b4! g4 3.Kd4! g3 4.Ke3! Kg5 {slowed} 5.b5! Kg4 {slowed} 6.b6! g2 7.Kf2! Kh3 {slowed} 8.b7! Kh2 {forced onto a queen-with-check square} 9.b8Q+ Kh3 10.Qg3#

Practical Chess Endings #25
Mandler 1938

White to play and win

Notice that White has a bishop pawn this time instead of a knight pawn in the two other studies. Again, one idea I have in endgames is that you should try to gobble your opponent's pawns as fast as you can. Here 1.Kxb7? only draws because Black can run down White's pawn beginning with 1...Kb3! 2.f4 (2.Kc6 Kc4! 3.f4 Kd4!=) 2...Kc4! 3.f5 Kd5!=. Of course, a pure pawn race only draws. 1.f4? b5 2.f5 b4 3.f6 b3 4.f7 b2 5.f8Q b1Q=. Instead, White wins by doing triple duty with his king: 1.blocking the Black king from chasing White's pawn along the a2-f7 diagonal, 2.slowing down Black's pawn advance later moves, and 3.helping to threaten mate after the pawns queen. 1.Kd6! Ka3 {slowed} (1...b5 2.Kc5 Kb3 3.Kxb5 Kc3 4.Kc5 {and White will preserve his pawn for the win.}) 2.Kc5! Ka4 {slowed} 3.f4! b5 4.f5 b4 5.Kc4 b3 6.Kc3! Ka3 {forced onto a queen-with-check square} 7.f6 b2 8.f7 b1Q 9.f8Q+ Ka4 10.Qa8+! Kb5 11.Qb8+ Kc5 12.Qxb1.

Endgame Caveat #5: Space Invaders

Researching for this post, I came across this 80's music video at YouTube. Cross-links at YouTube eventually led me to this free online Space Invaders game.

The Lucena position is an intermediate endgame position involving a non-rook pawn on its 5th rank, with the defender's king cut off from the queening square, generally precluding a Philidor defense.

The first caveat is that just because your king is cut off doesn't mean that the Lucena is inexorable. If Black doesn't pay attention, White could try 1. Ke2 Rf7? 2. Rf1!. Exchanging rooks allows a drawn pawn ending. If the Black rook moves away from the f-file, the White King crosses to g1 and White can choose either the Philidor (camp the rook on a3 until the pawn reaches g3, then go to a8 and harass the Black King from behind) or even the First Rank defense against a rook pawn or a knight pawn (just shuffle the rook back and forth from a1 to f1).

Black to play wins starting with 1... Kh4 2. Rh1+ Kg3 3. Rg1+ Kh3 4. Rh1+ Kg2 driving the rook away. After Rh6

Now 5... g3 6. Rg6 Kh2 7. Rh6+ Kg1 8. Rg6 g2 9. Rg7 sets up Lucena

Standard Lucena continues with 9... Re8+ 10. Kd2 Re5 11. Rg8 Kf2 12. Rf8+ Kg3 13. Rg8+ Kf3 14. Rf8+ Kg4 15. Rg8+ Rg5

The Space Invader will land at g1, spelling doom for the White King. Notice that the White King on d2 is too far after 16. Rxg5+ Kxg5 17. Ke2. From the previous diagram, had Black proceeded with 9... Rf5 10. Rg8 Kh2 11. Rh8+ Kg3 12. Rg8+ Kh3 13. Rh8+ Kg4 14. Rg8+ Rg5? 15. Rxg5+ Kxg5 16. Kf2 would be a draw.

Whew! So that's the background. From the first diagram, what if we move Black's King and Pawn back one step?

1... Kh5 2. Rh1+ Kg4 3. Rg1+ Kh4 4. Rh1+ Kg3 5. Rg1+ Kh4. Black's attempt to land the Space Invader is repelled because he can't protect the pawn at g5 while driving the rook away as he did before. The crucial thing is that the White Rook maintains distance from the Black King and Pawn. If White plays Rg2 to stall at any point, then he may be lost again. e.g. 1... Rf7 2. Rg2? Kh5! 3 Rh2+ Kg4 4. Rg2+ Kh4 5. Rh2+ Kg3 and the rook has to run, giving Black time to get into the Lucena groove with g4. Even spotting Black another file won't always give him the win.

As long as White keeps his king in the red zone and his rook at g1, he should be able to draw using the Space Invaders defense. One subtlety is that with White to move or a Black finesse, 1...Re7 2. Kd2? is losing. 2... Re5! protects g5 and creates enough forward momentum to let the pawn squeak to g4. 3. Kd3 (second thoughts?) Kf5! 4. Kd4 (4. Rf1+ Kg4 5. Rg1+ (5. Kd4 Ra5) Kf3 6. Rf1+ Kg2) Re4+ 5. Kd3 and either 5... g4 or 5... Rf4 stay on track toward Lucena.

There is still some trickiness to deal with. After 5... g4 6. Rf1+ Rf4 7. Rg1 Kg5 8. Ke2 threatens the aforementioned drawing maneuver, but calmly advancing 8... Kh4 removes the danger of Rf1. e.g. 9. Rf1 Rxf1 10. Kxf1 Kh3. After the trickier 5... Rf4 6. Ke2 g4! is the lone winning move followed by 7. Rf1 g3! another lone winner. Game Over, Man!

A long time ago, I read Jeremy Silman's When a Philidor Position Goes Bad. But missing so many RPvR endgames at ChessTempo continues to reinforce that it's not all just Lucena and Philidor.

Dragon's Lair

"Dragon's Lair: The fantasy adventure where you become a valiant knight, on a quest to rescue the fair princess from the clutches of an evil dragon. You control the actions of a daring adventurer, finding his way through the castle of a dark wizard, who has enchanted it with treacherous monsters and obstacles. In the mysterious caverns below the castle, your odyssey continues against the awesome forces that oppose your efforts to reach the Dragon's Lair. Lead on, adventurer. Your quest awaits!"

One of my favorite video games growing up was Dragon’s Lair. If I were to join the Knights Errant, I would be sorely tempted to replace the lame Sir Soapstone with Dirk the Daring. Dirk was always dying quickly and spectacularly. Man, did that machine eat quarters, two at a time. Now that I own the CD from Digital Leisure, I can use it to illustrate my chess blog. In a couple of scenes, slithering briars did Dirk in. Dragons and briars: that’s all the tie-ins I need for yet another themed post!

In my last post, I compared the thicket of variations in opening theory to a briar patch. Well, in Thursday night’s game, I dived right in and not surprisingly got totally excoriated. I decided to go into the heavy theory of the Sicilian Dragon, which I’ve only experienced from the Black side. The Dragon used to be one of my favorite defenses, but I got tired of being outbooked by teenage chess players whose ratings far underestimated their dragon-specific proficiency. Plus, perhaps the greatest dragon slayer of all time said that all he had to do was “sac, sac, mate.” My opponent had shown me what he does in a certain line of the 9.0-0-0 Sicilian Dragon that I always found annoying as Black. Armed with my new direction and this inside information, I decided I would turn the tables and see if I could surprise my opponent.

It didn't work out. The dragon bishop had me pinned with back rank threats in the late middlegame Just when I neutralized the dragon's fiery breath down the long diagonal, a pair of pint-sized Giddy Goons marched down the board and finished me off.

In the game, Dirk the Daring has five lives. In my postgame analysis, Fritz showed me five chances to get an even game. But I blew them all.

At the end of Dragon’s Lair, Dirk meets the dragon Singe and the love interest Princess Daphne. This is me after Nathaniel’s dragon got through with me.

My opponent claimed that by move 21, we were still in his opening theory. I had only memorized up to move 18. But there were two surprises: In my losing effort, I had fun. And I learned a few things. Many thanks to my opponent for explaining some nuances to me. His technique was not quite perfect, but good enough to win. My swindling technique was far from perfect, but I placed myself in a position to at least to have some chances. Strange how I didn’t feel nearly so bad as I felt after my last loss a few weeks ago. I’m on a streak of three losses in a row with five games coming up against experts. I hope I don’t become too comfortable with losing. I consider myself a pretty good sport - win or lose - with consistent gentlemanly behavior one of my highest ideals, but I still want to win and win in fine style. Without a competitive spirit, I might as well take up being a problemist.

Two knights battling on a chessboard