Thursday, 29 October 2015

Symmetric Chessboard Knight Tours

I've just completed an extensive piece of work collecting and constructing symmetric knight's tours on the normal chessboard. There are 183 tours on the page, showing all possible central angle formations.

Here is one group of tours from the page, (hh), (hi), (hj):
The first two are my own constructions the (hj) is from Wenzelides in Schachzeitung 1849.

It was only a month or so ago that I was able to see the work by Brede 1844 that contains 24 tours, all but #14 being in 180 degree rotational symmetry. It has become available due to digitisation. This was evidently an important pioneering work that seems to have been under-appreciated. The tours are at the end of the book:

There is also a semimagic tour formed of two copies of a 4x8 semimagic tour joined together.

Friday, 2 October 2015

Long Walk to the East Hill

Went for a good long walk from around 11:30 to 3 pm to get away from the noise of plastering work being done at last on the building where I live. Went into the Hastings old town, and up the steps to the West Hilll Cafe for fish and chips (though it wasn't really any better than I could cook for myself at home). From there I decided to follow the contour round with a view to ending up at East Hill. This took me eventually to steps leading up to what is shown on the map as Pinders Walk. From there to the beacon on East Hill and down all the steps and along the seafront. It was a lovely sunny day, but surprisingly few people about for most of the time.

This is the longest bit of walking I have done since  went to Ramsgate for the Thanet Chess Congress back on 21-24 August. It was sunny for most of the time there, and I walked every day the two miles to the venue and back, from the Oak Hotel by the Ramsgate Harbour. The walking seems to have cleared my mind too since I played quite well, scoring 3.5/5 in the Minor, I won the first three games, so at that stage was leading the tournament, but couldn't keep it up. I suppose I should have reported it here on my Diary at the time, but can't seem to keep it going regularly.