<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Just getting to this one, days late….<br><div><br><blockquote type="cite"><div>On Nov 15, 2023, at 8:58 AM, Steve Smith <sasmyth@swcp.com> wrote:</div><br class="Apple-interchange-newline"><div>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div><p>I have not (yet) read this critically, the introduction just
tweaked my (confirmation biased) interests:<br>
</p>
<blockquote><p><a href="https://linkprotect.cudasvc.com/url?a=https%3a%2f%2fmedicalxpress.com%2fnews%2f2023-11-brain.html&c=E,1,yAfT9hJo7uUSxtZmctr_nLsgLeaHFbiw3c00tgPiz-JIVENC_gRTqM1ZLoAQ6-QyWMJG6xRzx9-DhBbc_r7ZwTXSXHCoWZFQ3taU76Zkp-0V&typo=1" class="moz-txt-link-freetext">https://medicalxpress.com/news/2023-11-brain.html</a></p>
</blockquote></div></div></blockquote><div>Here is one of several research stories that Elwyn Berlekamp told to me during a visit to SFI many years ago in which I was his host (the closest I will ever come to the experience of those who hosted Erdos). </div><div><br></div><div>Elwyn was one of the principles of the MSRI research into mathematical analysis of combinatorial games. </div><div><br></div><div>Here was one project:</div><div><br></div><div>Subjects are shown a chessboard with pieces on it, for a short time, after which the board is cleared (remember Searching for Bobby Fisher: “Here; I’ll help you”), and the subject is asked to reconstruct the piece locations.</div><div><br></div><div>The subjects were in two categories: high-level chess players, and ordinary people who don’t really play seriously, though perhaps they understand the rules of the game.</div><div><br></div><div>I will recount to you the outcomes as they were told to me. I have not gone back to original sources so I don’t know if some stylization was added to “sharpen the edges” of the picture.</div><div><br></div><div>1. For pieces placed on a board by computer-random number generators, the experts and the novices were not much different in speed or reliability of replacing pieces.</div><div><br></div><div>2. When the arrangements were not randomly generated, but rather taken from various stages in the play of games by high-level players, suddenly a big gap opened up. The novices did about the same as they had done for randomly placed pieces at similar sparseness etc. The experts got much faster and more reliable.</div><div><br></div><div>The experimenters, of course, wanted to say something mechanistic about why. To do this they put eye-trackers on the subjects, to find out what they were looking at when presented with the blankened board and asked to rebuild. So: what did the experts look at first? This is where the tension of the joke is set up, to prepare for the punchline.</div><div><br></div><div>3. The place the experts looked first was at the “next good move” from what had been the position, and they then backfilled the pieces in the positions that had made it the next good move.</div><div><br></div><div><br></div><div>I find this story delightful. If I were less lazy and really needed it for anything, maybe I would do the work to find out how reliable it is.</div><div><br></div><div>Eric</div><div><br></div><div><br></div></div><br></body></html>