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Science Isn't Dead, But It Is Ailing - Part 6
by Your Raving Roving Science Correspondent [Jay Guevara] »
February 20, 2021
Saturday Afternoon Chess thread 02-20-2021

WGM Maria Fominykh (RUS)
No movie thread today.
Beginner Problem - Black To Play (1316)
Goal: Black can force mate in 3 moves
Hint: Get the rook to the back rank

8/6pk/p5p1/8/1pB1n3/1P2bbP1/P4r1P/5RK1 b - - 0 1

Checkmate
Intermediate Problem - White To Play (1311)
This is one of those rare occasions that you can force checkmate with only one knight (with the help of your king, of course)
Goal: White can force mate in 3 moves
Hint: Allow Black to advance his pawn and trap his king

8/8/8/4N3/8/7p/5K1k/8 w - - 0 1
Advanced Problem - White To Play (1285)
Usually, if I can't solve a problem, I'll cheat and give it to my app to solve, since I'm usually running out of time before I need to publish the chess thread. But I wanted to solve this one myself so I kept at it over a period of days and finally figured it out. I thought it was quite a tough nut to crack, but maybe some of you will have an easier go of it.
But I did feed to to my app to test my solution, and it seems to hold up. The app usually finds lines that I miss, and sometimes it's enough to demonstrate that my proposed win is flawed, but not this time. I was able to handle all of the unanticipated moves it threw at me -- my solution withstood all of the shocks. The decision tree did get a bit complicated, though.
So the goal is to obtain an overwhelmingly winning position for White.

8/2r2pRP/8/2p5/7r/8/k1K4p/6R1 w - - 0 1

(Click to enlarge)

(Click to enlarge)


Icelandic Sweater Babe #1

Icelandic Sweater Babe #2

(Click to enlarge)
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Problem Solutions
Beginner Problem - Black To Play

8/6pk/p5p1/8/1pB1n3/1P2bbP1/P4r1P/5RK1 b - - 0 1
My original solution was a mate in 3: 1...Rxa2+ 2.Rf2 Bxf2+ 3.Kf1 Ra1#. But no, NaCly Dog had to be a big smarty-pants and cook my solution by coming up with a better one:
1...Rg2+
2.Kh1 Rg1#
So it's a mate in two. Nicely done, Salty.
Intermediate Problem - White To Play

8/8/8/4N3/8/7p/5K1k/8 w - - 0 1
This is one of those exercises that are included in every beginning endgame book. The trick is to maneuver the knight so it can check on the corner square while Black's own pawn hemn him in:
1.Ng4+ Kh1
2.Kf1 h2
3.Nf2#
Advanced Problem - White To Play

8/2r2pRP/8/2p5/7r/8/k1K4p/6R1 w - - 0 1
1.Ra1+ Kxa1
2.Rg4! Ra7
The pawn that is about to queen cannot be captured: 2...Rxh7?? 3.Ra4#
Nor can Black queen his own pawn: 2...h1=Q 3.h8=Q+ Rxh8 (3...Ka2 4.Qb2#) 4.Ra4#
Nor can the obstructing rook be captured: 2...Rxg4 3.h8=Q+ Rd4 4.Qa8+ and mate to follow
3. Rxh4 Ra2+
Again, Black cannot queen his pawn: 3...h1=Q 4.h8=Q+ Ka2 5.Qb2#
There is also no hope in 3...Ra8 4.Ra4+ (4.h8=Q+ Rxh8 5.Ra4#) 4...Rxa4 5.h8=Q+ Ka2 6.Qb2#
4. Kc1 h1=Q+
5. Rxh1 Ra8
6. h8=Q+ Rxh8
7. Rxh8 and wins
Hope to see you all next week!
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Note: that cryptic line of letters and numbers you see underneath each board diagram is a representation of the position in what is known as "Forsyth-Edwards Notation", or F.E.N. It's actually readable by humans. Most computer applications nowadays can read FEN, so those of you who may want to study the position, you can copy the line of FEN and paste into your chess app and it should automatically recreate the position on its display board. Or, Windows users can just "triple click" on it and the entire line will be highlighted so you can copy and paste it into your chess app.
___________
So that about wraps it up for this week. Chess thread tips, suggestions, bribes, rumors, threats, and insults may be sent to my yahoo address: OregonMuse little-a-in-a-circle yahoo dott com.

posted by OregonMuse at
05:24 PM
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