w #21 1.Dd8+ Td6 2.Db7+ Tçç6 3.Da5+ T4ç5 4.Db3+ Tdç4 5.Dd2+ Téd4 6.Df3+ Téé4 7.Dg5+ é5 8.Df7+ Té6 9.Dd8+ Tçd6 10.Db7+ Tçç6 11.Da5+ T4ç5 12.Db3+ Tdç4 13.Dd2+ Téd4 14.Df3+ é4 15.Dg5+ Té5 16.Df7+ Tdé6 17.Dd8+ Tçd6 18.Db7+ Tçç6 19.Da5+ T4ç5 20.Db3+ Tdç4 21.Dd2‡ >

They offered a $100 prize for a double knight promotion helpmate. In this problem, Black would move first and both sides would cooperate to mate Black in five moves by marching a single pawn which would promote to a knight.

Just to illustrate the idea:

click for larger view

The intention, Black moving first, is 1.g5 a4 2.gxh4 a5 3.h3 a6 4.h2 a7 5.h1N a8N#. Black's g-pawn must jump two squares to avoid checking the White king, and must promote to a knight to avoid another check or covering the mating square on a8.

The foregoing was quoted in <The Life and Games of Akiva Rubinstein, Volume 1: Uncrowned King>, 2nd Edition, Revised and Enlarged, by Donaldson, John and Minev, Nikolay, Russell Enterprises, Inc. ©2006, at p. 269, in an extended passage excerpted from an article the above-identified source says appeared in the November 1912 issue of the <British Chess Magazine>.

"The "15 puzzle" is a sliding square puzzle commonly (but incorrectly) attributed to Sam Loyd. However, research by Slocum and Sonneveld (2006) has revealed that Sam Loyd did not invent the 15 puzzle and had nothing to do with promoting or popularizing it."

[ http://mathworld.wolfram.com/15Puzz... ]

MathWorld therefore gives the following as the relevant reference.

Slocum and Sonneveld (2006)

[Event "*"]
[Site "Stanley's Chess Room"]
[Date "1859.01.??"]
[Round "?"]
[White "Stanley, Charles H."]
[Black "Loyd, Samuel"]
[Result "0-1"]
[ECO "C01"]
[PlyCount "30"]

1. e4 e6 2. c3 d5 3. exd5 exd5 4. d4 Bd6 5. Bd3 Nf6 6. h3 O-O 7. Nf3 Re8+ 8. Be3 Ne4 9. Nbd2 Ng3 10. fxg3? Rxe3+ 11. Be2 Bxg3+ 12. Kf1 Nc6 13. Qc2 Ne7 14. h4 Nf5 15. Rh3 Rxf3+ 0-1

https://en.wikipedia.org/wiki/Sam_L...

Where is the missing 'L',

Found my mistake (whenever things aren't going quite right for me, I've learned to check first for "operator error" - surprising how often a mirror will show me the source of my difficulty). Seems there's this second, "post kibitz" button . . . . ---
This is what happens when you are just a little OCD and save stuff, like notes on scraps of paper, for decades. And then go through them in your old age.

In either the 1980s or 1990s I copied down the following self-help-draw by Sam Loyd, published in George Koltanowski’s chess column in the San Francisco Chronicle. Unfortunately, in those days I had not yet developed the habit of dating my notes. George couldn't have published it much earlier than 1981, based on my own history of interest in chess.

Perhaps someone who a.) has access to a searchable database of S.F. Chronicles, and b.) has sufficient time and inclination, will look up the source and offer an improved reference. My expectation that someone will do this is zero - I can easily think of a multitude of things to do which are more important, like breathing.

(I had to copy the entry, as opposed to clipping the column from the paper, since the paper wasn’t mine and the owner wasn’t finished passing it around our little group of chessnuts.)

Having read all the posts on c.g.’s bio of Sam L. through yesterday, I see that at least I’m not posting old news (though some of you may be familiar with this challenge).

Interesting to read past posts on Sam's shortest stalemate puzzle and it makes me wonder if the challenge I’m posting was developed first or was part of Sam's study leading to his stalemate puzzle. My guess is that it was. I doubt this can be a proper puzzle, since I imagine there’s more than one solution, given the number of moves required.

Perhaps Sam worked much as some mathematicians do, just following leads for the sheer fun and joy of it. Just my guess, with zero basis in known references. This one just has a feeling about it (to me) of Sam’s perverse sense of the silly. Though, judging from his photo above, Sam had no perverse sense of anything. Or else he did, of everything. Or maybe he's simply trying to fight off volcanic diarrhea.

And while c.g. member Nikolaas may no longer be with us here at c.g. all these years later (trusting he’s well), I can offer him what has got to be one of the most brutally ridiculous retrograde analysis positions ever devised. It's by Sam Loyd and it goes like this:

click for larger view

Achieve this position starting from a full board in just 17 legal moves for each side.

Given that I’m now 66, I’ll post Sam's solution when I remember to. Both friendly reminders and complete disinterest are welcome. Which goes with the turf when you’re 66.