Hello I need some help with this puzzle. It is supposed to be mat in 3 moves for white I cant se that and Ive tried to make fritz solve it but I dont know how to. I would be happy if someone could help me to se if it is correct and there is mate in 3 moves. If you know how to use it computerhelp might be good.

Edit:  

    THE Text below is WRONG, totally WRONG - although it works, there is a mate in three.  keep reading.     I was wrong again. darn it all.

Hello John.  

   now to your question:   First, you notice black's king can not move, and any check is mate.  Next, how can white maneuver to 'cover' all possible escape squares while getting ready to apply checkmate.       and soon, one would give up on a mate in 3 in frustration and turn on one's engine (deep fritz 8) for instance (mine)  and find out, in about 4 seconds - that there is NO mate in 3 available if black provides good resistance.

Thus, below are the lines derived by my engine.

New game,
n7/6K1/4R3/3p4/1p1k4/8/1PQ2N2/8 w - - 0 1

Analysis by DEFECTIVE   Deep Fritz 8:

1. +- (#4): 1.Qb3 Kc5 2.Nd3+ Kd4 3.Qxb4+ Kxd3 4.Qc3#
2. +- (#4): 1.Qd2+ Kc5 2.Nd3+ Kc4 3.Qxb4+ Kxd3 4.Qc3#
3. +- (#4): 1.Qd1+ Kc5 2.Qc1+ Kd4 3.b3 Nc7 4.Qe3#
4. +- (#4): 1.Qc1 Nc7 2.Qf4+ Kc5 3.Nd3+ Kb5 4.Qxb4#

Thanks!

HUH??!

I found a puzzle. It was on a chessclubs website and I tried to solve it but it was hard...

Then I thought about putting it up here so that someone who can put it in to fritz could show the answer if there was any. It wasn't...

I have only put up a chess diagram there not a puzzle to solve.

My little engine shows the following line as being available;-

1 Qc6 Nc7

2 Qxc7 b3

3 Qc3#

Homer, what if Nb6 instead  of Nc7 ?

Isn't Re5 checkmate?

---

Re5 isn't even check. 

Yeah I get another M3 line as well (with Nb6)

1.Qc6 Nb6 2.Re5 Kxe5 3.Qf6#

---

 That takes 4 then.

so, my engine wasn't wrong?   cool.  that is a little reassuring.    thanks Homer. you aren't really as evil as they say.  (but then, what do "THEY" know anyway ?)

---

You're absolutely right there, bunch of know nothing know it alls!

An alternative line from my little engine for a look is

1 Nd3 Nb6

2 Qc5+ Kxd3

3 Re3#

As far as I can see it works with 1..... Nc7 too?

4. +- (#4): 1.Qc1 Nc7 2.Qf4+ Kc5 3.Nd3+ Kb5 4.Qxb4#

Isn't correct (there's a faster way to mate if Black chooses Nc7). 1.Qc1 Nc7 allows 2. Qxc7 forcing b4 3. Qc3#

you probably ment the line:

4. +- (#4): 1.Qc1 Nb6 2.Qe3+ Kc4 3.b3+ Kb5 4.Qxb6#

---

 Are you sure you set this up right?

That looks about honours even after that sequence?

---

 That looks about right, but is there a forced mate in 3?

you are right. the puzzle is wrong. mate in 2 not 3

---

 Mate in 2?

What are the moves?

yes, there is a forced mate in 3.   memory working now, I saw this one years ago.

my engine is wrong, I will readily admit.

as long as white's queen stays on the c file, black's move are completely forced.

 

Homer has it right.

                 my engine is evil, I believe.  misleading me so badly.

after 1. Qc6

if                  b3  2. Qc3#

if Nb6  2. Re5    Kxe5 3. Qf6#    or     Nc4 3. Qxd5#   

if Nc7  2. Qxc7 b3  3. Qc3#

 

and there you have it, ladies and gentlemen. 

---

 My engine is just free rather than evil, so not the strongest in the world, but hey, we got there in the end. 

Nice puzzle by the way !