x
Chess - Play & Learn

Chess.com

FREE - in Win Phone Store

# 9/15/2011 - Mate in 9

• #1
• #2

freshbacon & lycanwerewolf PROO

• #3

I was surprised I got the first 3 moves correct.

• #4

Too easy for Thursday

• #5

lett!!

• #6

Clever puzzle.

• #7

You have to start off with your Knight in order to free a path up for your Bishop.  If you start off with your Rook, then you pretty much come to a dead end.  Black has an option to capture your Knight with his pawn, but that willl only lead to a Mate in 3.  After that, all of the moves are forced and Black's fate is sealed.

.

The following is a copy of Post #155 on Page 8 by @elindauer:

I take decisions in these puzzles exactly the way I play OTB.  My goal is to find the best move with the least amount of calculation.  In this case, I solved the puzzle in 3 steps:

phase 1: calculating forcing lines

- check material, see that white is winning.

- start calculating forcing lines.  My first glance was Rd7+ Kb8 Rxg7.  I evaluate this as winning for white but not resignable yet.  This becomes my main line.

- consider other forcing checks / captures.  I happened to look at Nb5+ next.  First I tried Nb5+ cxb5 Rd7+.  The king has a couple choices, I tried Kb8 Be5+ Ka8 and ran into a wall.  I evaluate this as worse then my main line and discard it.  I note that letting the king get to a8 kills my attack, and try Nb5+ cxb5 Be5+ Kc6.  I look for forcing continuations, and see Rc3+, Bd7+ ... oh, Bd7+ Kc5 Bd6#... is mate!  ok.  So Nb5 cxb5 wins for white.

Now I looked at Nb5+ Kb8 Bd4+ Ka8 Nc7+ Kg8.  I can see that Ne6+ here wins the exchange, and I already evaluate this as better than my main line.  So I cut off my calculation and call this my main line.

Return to calculating forcing lines in the original position... Nd5+ cxd5 ... wait, no, Nd5+ Kb8 transposes to the main line and this is black's option.  No need to calculate Nd5+ cxd5 since black will only play this if it worse for me then my main line.  Ignore.

So I am ready to move.  I go to the puzzle and play Nb5+ Kb8 Be5+ Ka8 Nc7+.

Phase 2: where to put the knight.

- from phase 1 I already have a main line: Ne6+ Ka8 Nxc8.  I extend a little farther and see Rxc8 Bxg7 picking up another pawn too.  I evaluate this as totally winning for white.  In time trouble I would play this instantly.  With a few minutes to spare, I calculate the alternatives:

- Na6+ Ka8 and I see nothing better then just Nc7+ repeating moves.  Discard.

- Ne8+... aha this allows Rd8... Ka8 Rd8+ Bc8 Rxc8+ Kb7.  I can't stop calculating just yet since the knight is pinned.  However I see that Rc7+ followed by Ne6 will save the knight.  Since I prefer to win the bishop then to win the exchange, and I can see that there is still some life in this line left to calculate, I evaluate this as better then Ne6+ and continue...

- Rd8+ Rxd8... Ne6+... nothing really coming to mind here.  I am ready to move.

So I go to the puzzle and play Ne8+ Ka8 Rd8+ Bc8 Rxc8+ Kb7.

Phase 3: calculating the win.

Same song, different verse.  I know that I have Rc7+ and just save the knight, with a winning 3 minor pieces vs a rook endgame.  I calculate a few more forcing lines to see if there is a mate:

- Nd6+ is nice, only 1 answer... Ka6... Bf1+ b5... Bxb5+ cxb5 Rc6+ Ka5... seems promising but I'm not quite seeing the knockout.  I put this under "consider again later" and return to other ideas

- Rb8+ Ka6 Bc8+ Kb5 I have h5+, f5+... oh wait, I see that Rb8+ Ka6 Nc7+ only allows Ka5... now Bc3+... is mate!  ok I'm ready to play.

Rb8+ Ka6 Nc7+ Ka5 Bc3 winner winner chicken dinner.

So this mate in 9 can be taken over the board as three different 3 move combinations.  You don't have to see the whole thing up front to solve it.  Hope that helps.

• #8

Amazing.

• #9

A very clever puzzle, even though I need someone to fully analyze it to spot why cxb5 isnt good of an answer

• #10

long drawn out.

• #11

nice one especially the first move of knight

• #12

good one

• #13

long but nice puzzle

• #14

good one!

• #15

I became unstuck with this puzzle as there is no Queen to sacrifice.

• #16

Nice one.

• #17

AWESOME

• #18

I like when the king is under pressure.

GO PIRATES!

• #19
AasTmO wrote:

A very clever puzzle, even though I need someone to fully analyze it to spot why cxb5 isnt good of an answer

hi  AasTmO,

if cxb5 then Be5+ Kc6, Bd7+ Kc5, Bd6#

• #20

yup great puzzle... :)

Top
or

Online Now