Christmas Puzzles: solutions (2)

The twin problems by artist Abraham Jacob Bogdanove (reconstructed from a painting by Luke Neyndorff) were fairly simple.

In both diagrams there is an engine waiting to play defensive moves and prevent White from mating in two and one moves. So it will be fairly easy for you to follow the solutions:

Problem 1: 1.Ne2 Kxd2 (1...cxd2 2. Nf4#; 1... Ra1 2. Nf4#; 1... Nc2 2. Nxc1#) 2. Nf4#. 
Problem 2: 1.exf8=N#.

To help you get over the one-mover we showed you two unusually long problems by James Malcom. In the first Black will gladly move his bishop between g1 and h2, unless we force him to play something else – which should be a mate.

In the second problem White's goal is to castle long, while Black is bent on preventing exactly this! It turns out that White needs 67 moves to force Black to allow O-O-O. This sounds insane, but it is quite logical once you have understood the basic logic.

So who is the author of these imaginative many-move problems. Some elderly problemist with decades of experience, you may think? Well, think again.

James Malcolm is a 17-year-old high-school student! He lives in Iowa, USA, and just like chess enthusiasts his age, loves playing online games. But he is different in one aspect, he also takes a lot of pleasure in composing chess problems, and he is especially fond of record tasks, jokes, and anything related to the three special moves of chess: castling, promotion, and en passant.

A rather uncommon interest for a young man!

Christmastide Solving Contest

On December 25 our colleagues at ChessBase India staged a solving contest in which around a large number of enthusiasts took part. They were not just from within India, but also from various parts of the world, like Germany, Romania, Russia, USA – to name just a few! What was surprising was the outstanding quality of these entries. At least 17 readers who wrote in had perfect solutions, and twice more scored more than fifty percent. This is what a solution to the 76-mover looks like in Hindi.

How many moves to mate?

In 1986 John Nunn sent us a chess problem by Danish composer Walther Jørgensen. It was, at the time, the longest dual-free direct-mate with a legal starting position that had ever been devised. You can replay this astonishing 203-mover on our replay board below, and understand everything, thanks to the comments by John Nunn.

On our December 31 puzzle page I predicted that this 44-year-old record would probably have been broken. Within a day problemist Werner Keym informed me that it had indeed been increased to 226 moves – by the same Walther Jørgensen, using the same basic pattern.

The picture of Walther Jørgensen (1916-1989) was taken from Thema Danicum, the publication of the Danish Chess Problem club.

Note that you can click the Autoplay icon to have the entire solution replayed for you – while you sit back and enjoy your coffee or mate tea?! Shift+Autoplay click is slowest replay, Ctrl+click is faster and Alt+click is fastest.

A logical non-chess problem

What have I done? Ten years ago, at a German railway station, I had asked young grandmaster Anish Giri why the overhead power lines ran zigzag instead of straight. I posed this innocent question to our readers.

Looking from above (even from a bridge) you can clearly see that the power line trace a zigzag path above the trains, and that this has been done purposefully: the masts have longer and shorter arms.

Anish was baffled, and when I brought it up a few weeks ago he still didn't have an answer. Neither did a dozen 2750+ GMs, who have been working on the problem for weeks now. Some days ago Anish got it, but only after I had helped him – I gave him a video showing the bow collector (pantograph) getting power from the overhead line. You can watch some of this seven-minute video and see if you also hit on the answer.

Interestingly two readers had the correct solution. One of them, Albitex, is an electronic technician and who worked for a railway signalling company. No wonder. Also Vishy Anand solved it – his father worked in the railways. But even highly educated scientists – quantum physicists, astronomers, mathematicians – as well as the super-GMs – didn't even get close.

Now for the answer. The reason for the zigzagging is incredibly simple: if the power wire was straight it would cut through the bow collector, like a chain saw, in a couple of miles! The wire need to glide back and forth over the collector for it to last. Watch the video above.

This is what would happen after a mile or two if the power line were straight. The wire would stay in the groove and continue to cut through the bow collector. 

Sorry to have spent such a lot of time on this – it spun unexpectedly out of control. And now a dozen close friends will be cursing me. I must be more careful in the future. For the “gimme-more” friends and readers here are a few more non-chess New Year’s puzzles.