Witty endgame study

[Tony Gardner]

The following study comes from the chess page of Tim Krabbé, renowned Dutch collector of chess gems and curiosities:

[Antrax]

I'll take the first wrong stab: e8=N? RxN or anywhere along the e column then obvious Ra1 mate, if RxR then Nd6 and unavoidable Nb7 mate. Other rook moves along the first row are answered with Nd6 and if RxN or moving to block Nb7, then Ra1 mate.
What'd I miss?
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[Antrax]

Oh, I see a line I missed: ..Rg1 and if Nd6 then Rxg4+ with either endless check or forced stalemate, and if RxR then hxR=Q and I don't see a way to escape at least perpetual check (most likely an actual mate is in there somewhere).
So, I guess back to the drawing board.
_________________
After years of disappointment with get rich quick schemes, I know I'm gonna get rich with this scheme. And quick!

[Nsof]

i think it will still work with 1. e8=Q Rg2 2. Kh5 so if 2...RXg4 then 3 Ra1#
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[Zag]

I still don't think that works, Nsof.

1. e8=Q (or N) Rg1
2. Kh5 Rf1

You could then move g5, and march the king and pawn down as he bounces between f1 and g1, and you promote yet another pawn, but it doesn't do you any good, that I can tell.

if you leave the king still for a turn, the R can put him into perpetual check, and you don't have a one-move mate with a Q or a N on e8, while the black rook stays on the 1 row.

[Nsof]

missed that.
_________________
Will sell this place for beer

[Zag]

got it
1 sec

[Zag]

crud. never mind

I was thinking that you could start by promoting the pawn to Q, then walk the other pawn down, become a queen, then walk it back up to the 5 row. Now you have two queens attacking b5. However, if you promote to Q and not N as Antrax suggested, then RxR stops you, I think.

[Jack_Ian]

After a quick look at the puzzle, I suspect that the pawn on B2 must play an important role, since it's not needed to keep the King trapped.. It looks very interesting. I'm looking forward to examining it when I get a chance.

[Zag]

Oh, I know what purpose that pawn plays. It keeps you from moving a Q to a1 without first moving into the 1 row.

Without that pawn, start with Antrax's promote to knight, and his later black response of using the rook to threaten perpetual check constantly. With the black rook bouncing back and forth, walk the other pawn to become a queen, walk it back up one step, then strike on the diagonal.
1. e8=N Rg1
2. Kh5 Rf1
3. g5 Rg1
4. Kh6 Rf1
5. g6 Rg1
6. Kh7 Rf1
7. g7 Rg1
8. Kh8 Rf1
9. g8=Q Rg1
10. Qg7 Rf1
11. Qa1+ RxQ
12. RxR#

but 11 is impossible with the b2 pawn.

[Zag]

OK. I really have it this time. Like all good hints, it only makes sense once you no longer need it.

Like before, but walk the king and queen all the way backwards to the 3 row, in the reverse of how you walked the pawn up to promote it, plus one more row.
1. e8=N Rg1 (include Antrax's reasons that this is black's only option)
2. Kh5 Rf1
3. g5 Rg1
4. Kh6 Rf1
5. g6 Rg1
6. Kh7 Rf1
7. g7 Rg1
8. Kh8 Rf1
9. g8=Q Rg1
10. Qg7 Rf1
11. Kh7 Rg1
12. Qg6 Rf1
13. Kh6 Rg1
14. Qg5 Rf1
15. Kh5 Rg1
16. Qg4 Rf1
17. Kh4 Rg1
18. Qg3 Rf1
Now, with the black pawn at h2 in the rook's way, you are safe from perpetual check by the rook.
19. Nd6 Rf4+
20. Kh3 Rh4+
21. Kg2 R moves anywhere
22. Ra1#

[Tony Gardner]

Spot on, Zag!

Krabbé includes the comment that the "unthematical" (as he calls it) 16.Qg3 is in fact one move quicker:
16. ... Rf1
17. Kh4 Rd1 (Rf4+ 18. Kh3 Rh4+ 19.Kg2 and 20. Ra1#)
18. Nd6 Rd4+
19. Kh3 Rh4+
20. Kg2 any
21. Ra1#

Apparently, in English there is no expression for this specific situation, i.e. a rook that threatens to continuously check the king and cannot be taken due to immediate stalemate. Krabbé has termed it the 'rambling rook', in analogy to the Russian (beshenaya ladya) and Dutch (dolle toren), both literally meaning "crazy rook".

[PuzzleScot]

Am I missing something?

e8=N Rg1
Kh5 Rxg4!
Nd6 (say) Rg5+
Kh4/6 with perpetual check from there on, with R on g and K on h.

[Zag]

Yep. As soon as black's rook leaves the 1 row, he must keep white in check the whole time or he loses.

e8=N Rg1
Kh5 Rxg4
Ra1#

[PuzzleScot]

Just had that 'Aaaaahhh of course!' moment. Nice one. Thanks.

I remember an excellent end-game puzzle where the pawn was promoted to a different piece dependant on black's move.
When I say remember... anyway, this is nearly as good as that

[mith]

Thinking of this?