There is one thing I never do, never ever<\/i> do, when I complete a Sudoku puzzle.<\/p>\n
I never guess.<\/p>\n
Sherlock Holmes famously said in The Sign of Four<\/i> that a guess is “destructive to the logical faculty,” and I am not inclined to disagree. When it comes to Sudoku I puzzle it out, I think it through logically. I never put down a number until I am absolutely sure<\/i>, even though that may mean that a puzzle will go unsolved.<\/p>\n
I never guess.<\/p>\n
Today, today I guessed.<\/p>\n
On the train in the morning and evening, I will do the Sudoku puzzle printed in b<\/a><\/i>, a local free daily paper. Usually, I’ll finish the puzzle on the train in the morning between State Center and Timonium, a ride of roughly twenty minutes. Sometimes, I’ll work on an unfinished puzzle on the evening train back home.<\/p>\n (Morning, I use a red pen, evenings blue. If I have to go back to the puzzle a third<\/i> time, say on the subway out of town, I use black.)<\/p>\n This morning’s puzzle, in its early going, was simply, easy, perhaps deceptively so. As General Chang said, I was “lulled into a false sense of security.” The low-hanging fruit picked quickly, leaving behind more challenging fruits. I stared at the puzzle for whole minutes, stymied in my logical deductions, not putting down a single digit. All the tricks I knew came up short. I had the puzzle half done, I knew where certain numbers had<\/i> to go, but I wasn’t sure<\/i>. I couldn’t prove anything.<\/p>\n In one square of nine, I had five digits filled in. For the rest — the 2 could only go here or here, the 6 could only go here (overlapping with the 2) or here, the 1 and 8 could only go in the corners (overlapping with the 2 in one corner, overlapping with the 6 in another). I kept looking at this, and I reasoned. “If 2 goes here, then 6 goes here, and the Schr\u00f6dinger’s 1 & 8 go here and here. Or, if 2 goes there, then 6 must go there, and the Schr\u00f6dinger’s 1 & 8 must therefore go here and here.” I could not prove one state or the other; based on the solved state of the puzzle at that moment, both solutions to this nonant of the puzzle were correct. And even if I could place the 2 and the 6, I couldn’t solve the 1 and the 8; like Schr\u00f6dinger’s Cat<\/a>, these numbers were simultaneously in two states.<\/p>\n I wrote down “maps” of both solutions in the paper’s margin. I stared at them. I thought about them.<\/p>\n But there was nothing to think<\/i>. I couldn’t prove anything. Either the first solution was true or the second solution was true, and one was as likely as the other.<\/p>\n I went with the second solution. I wrote down the 2. I wrote down the 6.<\/p>\n I couldn’t even say I had had an intuitive leap. All I could say, truthfully, was that I had made a guess.<\/p>\n And I never guess at Sudoku.<\/p>\n If my guess were wrong, I would know very<\/i> soon. Numbers would double up somewhere. I would scrawl a giant “X” across the busted puzzle.<\/p>\n Instead, numbers kept falling into place.<\/p>\n In very short order, I had the puzzle solved.<\/p>\n All because of a guess. A 50\/50 guess, but still a guess nonetheless.<\/p>\n I got lucky. I could so easily have gone for the other solution, and I would have ruined the puzzle irrevocably. Like Schr\u00f6dinger’s Cat, the puzzle existed in a state of indeterminacy. Until I made a decision on the nonant, until I placed the numbers, the puzzle could not be solved. And like Schr\u00f6dinger’s Cat, my very act of determining the numbers produced a result — the puzzle could live (and be thus solved) or die (and be thus busted), but unless I acted, I would never know. The uncertainty had to be broken down.<\/p>\n I never guess.<\/p>\n","protected":false},"excerpt":{"rendered":" There is one thing I never do, never ever do, when I complete a Sudoku puzzle. I never guess. Sherlock Holmes famously said in The Sign of Four that a guess is “destructive to the logical faculty,” and I am not inclined to disagree. When it comes to Sudoku I puzzle it out, I thinkContinue reading <\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[52],"tags":[396,651],"class_list":["post-5113","post","type-post","status-publish","format-standard","hentry","category-life","tag-silly","tag-sudoku","entry"],"_links":{"self":[{"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=\/wp\/v2\/posts\/5113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5113"}],"version-history":[{"count":0,"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=\/wp\/v2\/posts\/5113\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5113"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.allyngibson.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}