Blog

Notes from behind the scenes: how our puzzle games are built, where classic puzzles come from and what we learn while making them.

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  How We Guarantee a Mahjong Solitaire Board Is SolvableA developer's look at how Tilelings builds every Mahjong Solitaire deal backward from an empty board, so that a solution always exists.
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  Mahjong Solitaire History and How It Differs From MahjongA short history of Mahjong Solitaire, from a 1981 computer game to today's phones, and how this one-player tile puzzle differs from classic Mahjong.
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  How a Daily Puzzle Can Be the Same for Everyone, No ServerHow a game can give every player the same daily puzzle without a server: date seeds, deterministic randomness, time zones and what cheating looks like.
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  How Hundreds of Puzzle Levels Are Generated and CheckedHow puzzle games create hundreds of levels without drawing each by hand: generators, solvers, measuring difficulty, working backwards and hill climbing.
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  Tic-Tac-Toe: A Solved Game, an Early Computer and Its VariantsFrom OXO on EDSAC in 1952 to Ultimate Tic-Tac-Toe: why it is a solved game, how small its game tree is and which bigger variants keep it interesting.
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  Earthquake Magnitude vs Intensity: What Is the Difference?Magnitude measures the energy released by an earthquake, intensity measures the shaking at a place. Learn how Richter, Mw and Mercalli scales differ.
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  Earthquake Preparedness: Before, During and After (AFAD)A calm checklist based on AFAD guidance: prepare a disaster bag, Drop-Cover-Hold On during shaking, and what to do after an earthquake in Turkey.
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  Where Does Earthquake Data Come From? AFAD, Kandilli, USGSWhy do two agencies report different magnitudes for the same earthquake? How AFAD, Kandilli and others publish, revise and update recent earthquake lists.
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  What Is BMI? How to Calculate It and Read the ResultWhat body mass index (BMI) is, the kg/m2 formula, the WHO adult categories, worked examples and how a healthy weight range for your height is found.
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  BMI Mistakes and Limits: Athletes, Age, Pregnancy, UnitsCommon BMI mistakes and limits: why athletes, older adults, pregnancy and children need care, and how cm/kg and ft/lb mix-ups ruin a result.
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  How to Calculate Exact Age in Years, Months and DaysHow to work out exact age in years, months and days by hand, with borrowing examples, days until your next birthday and how month lengths cause confusion.
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  Leap Day Birthdays: How Do You Count Age on 29 February?How people born on 29 February count age and celebrate: the leap year rule (4, 100, 400), leaplings, 28 February or 1 March, and how age apps treat it.
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  Pentominoes: The Story of the 12 Pieces and GolombWhat a pentomino is, how Solomon Golomb named and studied them in the 1950s, how Martin Gardner made them famous and why a 6x10 board has 2339 solutions.
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  How We Build Pentomino Levels with Dancing LinksA developer story: how exact cover and Knuth's Dancing Links solve and generate Pentolings levels, from 63 piece positions to unique puzzles and hints.
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  How a Tombala Card Is Generated: Six Cards, Ninety NumbersDev notes: how Tombalings builds a Tombala card set where six cards cover 1 to 90 exactly once, and how the rivals are timed to feel human.