problem #19666

[blacura]

It looks like there is a forced mate after Rc8+. All possible moves after 1.Rc8+ Kb7 2.R1c7+ Ka6 3. b5+ lead to mate.
A) 3...Qxb5 4.Rxa7+ Kxa7 5. Qb8+ Ka6 6.Qa8 mate
B) 3...Kxb5 4.a4+ Ka6 (4...Ka5 5.Rxa7 mate) 5.Rxa7+ Kxa7 6.Qb8+ Ka6 7. Qa8 mate
C) 3...Ka5 4.Rxa7 Kxb5 5.a4 mate (or 5.Qa4 mate)

[richard]

I'm afraid I have trouble following this.  At what point is 1. Rc8+ played?

Regards,
Richard.

[blacura]

Sorry for not being clear on the original post. The solution begins 1. Rc1 Qxd5 2. Rxc7 Re8 and NOW White can force mate with 3. Rc8+ etc.

[richard]

Hi Blacura

The computer doesn't seem to see mate, the best line after 1. Rc1 Qxd5 2. Rxc7 Re8 3. Rc8+ according to my computer is your line B) however the computer chooses Rxe8 instead of a4+, if your line is played out then 7. Qa8 is not mate as the black queen is protecting that square so that line seems to lose badly after Qxa8.  Am I missing something?

Regards,
Richard.

[blacura]

Oh....I overlooked that defense (....Qxa8) Thanks for looking into it, Richard.

[richard]

No problem.  I only see those outcomes with the help of the computer.  I'd never see it over the board :-)

Regards,
Richard.