The Curious Engineer

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Possibly Wrong

possiblywrong.wordpress.com

On science, mathematics, and computing

MathAlgorithms / data structures

’10’15’20’25
Posts
297 from 21 May 2010 to 26 Sep 2026
Posting
monthly (8 in the last year)
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personal blog
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2026 6

  1. The best years for movies
  2. Using AI to create a magic trick
  3. Alice and Bob on Two-Pi Day
  4. Comments on: What Every Experimenter Must Know About Randomization
  5. Analysis of Biscuits dice game
  6. Analysis of Mastermind-like bottle match game

2025 10

  1. Riddler Solution: Can You Skillfully Ski The Slopes?
  2. Variants of Fitch Cheney’s Trick
  3. The criminal coupon collector
  4. Binomial proportion estimation with unknown and varying number of trials
  5. A trick-taking game
  6. Fiddler Solution: Can You Hack Bowling?
  7. A maximally inefficient Monte Carlo estimate of pi
  8. How shallow is the cut card effect?
  9. Historical probability of picking a perfect bracket 1985-2025
  10. Expected time to complete a WOW board row or column

2024 11

  1. Optimal strategy maximizing expected value for splitting pairs
  2. Another Secret Santa puzzle
  3. An algorithm incorrectness proof
  4. Analysis of adversarial binary search game
  5. Robot simulator updated to VPython 7.6.5
  6. Another whodunit logic puzzle
  7. Strongly solving Gobblet Gobblers using retrograde analysis
  8. Another coin flip puzzle
  9. Inverse Coupon Collector’s Problem
  10. Lemonade Stand
  11. Exact analysis of Dreidel game

2023 11

  1. Analysis of Left-Center-Right dice game
  2. Counting Olympic medal podiums
  3. Coupon collector’s problem variants with group drawings
  4. Angle interval intersection
  5. East of here
  6. Grid search puzzle
  7. The pigeonhole principle: the converse is false
  8. Playing the subtraction game with GPT-4
  9. The friendship paradox: expectation vs. probability
  10. Historical probability of picking a perfect NCAA bracket 1985-2023
  11. The hardest polycube packing puzzle

2022 8

  1. A wrong solution to the Riddler sock matching problem
  2. Probabilities in one-card Nomination Whist
  3. Counting marked dice
  4. Analysis of horse racing board game
  5. Rube Goldberg Monte Carlo
  6. NCAA tournaments are getting measurably wilder
  7. Bresenham’s circles are (always?) optimal
  8. String art

2021 10

  1. There is no equilux
  2. Squid Game expectation
  3. Code name generator
  4. Expected length of a soccer penalty shootout
  5. Counting collisions
  6. Beware the “natural” quaternion
  7. Analysis of Evil Hangman
  8. An updated Google Books word frequency list
  9. Balanced clock hands
  10. What is the probability of a tie vote?

2020 16

  1. Counting edge-matching puzzles
  2. The Fisher-Yates shuffle is backward
  3. Among Us: Morse code puzzle
  4. Counting Hotel Key Cards
  5. Exploiting advantage from too few shuffles
  6. Giant Yahtzee
  7. MATLAB’s colon operator and for loops
  8. Computing the angle between two vectors
  9. Ambiguous notation for logarithms
  10. Sliding rooks (and queens)
  11. Seven riffle shuffles is not enough– except when it is
  12. History of COVID-19 cases
  13. Fair dice: some isohedra are less fair than others
  14. Solving the 2x2x2 Rubik’s cube (revisited)
  15. Another dice puzzle
  16. Tracking a card through a shuffled deck

2019 15

  1. A different sock matching problem
  2. The hot hand
  3. Gambler’s fallacy fallacy?
  4. Reproducing randomness
  5. The distribution of “roll and keep” dice
  6. Snap card game probability
  7. Poker puzzle
  8. Calling Java from MATLAB with pass-by-reference arrays
  9. How to tell time using GPS, and the recent Collins glitch
  10. A potential exploit of a Mountain Dew promotion
  11. Tracking heap memory use in Windows
  12. Follow-up: I found two identical packs of Skittles, among 468 packs with a total of 27,740 Skittles
  13. Printing a single-elimination tournament bracket
  14. The answer is always “None of the above (or below)”
  15. Identical packs of Skittles

2018 14

  1. Random drug testing in the NFL
  2. Generating Mini-Crosswords
  3. Disabling subnormals in MATLAB
  4. A lattice path puzzle
  5. Arbitrary-precision rational arithmetic in C++
  6. Uncertainty in trading passengers for fuel
  7. An urn puzzle
  8. On average, we die a decade earlier than expected
  9. How many melodies are there?
  10. Picking a perfect NCAA bracket: 2018 was the most unlikely tournament so far
  11. Whodunit logic puzzle
  12. Coupling from the past
  13. How high can you count in limited space?
  14. Proofs and theorems without words

2017 18

  1. Hilbert halftone art
  2. Probability of playable racks in Scrabble
  3. Analysis of Bingo
  4. Digits of pi and Python generators
  5. Floating-point agreement between MATLAB and C++
  6. What is (-1&3)?
  7. The following are equivalent
  8. Dice puzzle
  9. A number concatenation problem
  10. Cutting crown molding
  11. Iterative Poohsticks
  12. Horse race puzzle
  13. The hardest 24 puzzles
  14. Anagrams
  15. Array resizing in MATLAB
  16. Guess the number
  17. Probability of a Scrabble bingo
  18. Risk of (gambler’s) ruin

2016 16

  1. A harder birthday problem
  2. Strong induction
  3. How many dice?
  4. Distribution and variance in blackjack (Part 2)
  5. Distribution and variance in blackjack
  6. Serializing MATLAB data
  7. IBM Research Ponder This: August 2016 Puzzle
  8. Twisty lattice paths, all alike
  9. Rainbows
  10. Category theory without categories
  11. Sump pump monitoring with a Raspberry Pi
  12. NCAA tournament brackets revisited
  13. Analysis of (hexagonal) Battleship
  14. Home-field advantage
  15. Analysis of the game of HIPE
  16. Secret Santa solution with burritos

2015 20

  1. Secret Santa puzzle
  2. Proofreading as “mark and recapture”
  3. College football bowl confidence pools
  4. Coin flip puzzle
  5. Arbitrary-precision integer arithmetic in C++
  6. Kanoodle, IQ Fit, and Dancing Links
  7. The clueless student: solution
  8. The clueless student
  9. Train tracks and graph theory
  10. Floating-point round trips revisited
  11. Floating-point round trips
  12. The fourth-best for the job
  13. NCAA bracket scoring systems
  14. Hangman, Scrabble, and Google Books
  15. Time management in distributed simulation
  16. Update: Chutes and Ladders is long, but not *that* long
  17. Analysis of Chutes and Ladders
  18. Searching for chocolates
  19. One-card draw poker
  20. Calories in, calories out revisited

2014 24

  1. Pick any two cards
  2. Card shuffling algorithms, good and bad
  3. Probabilities in Knockout: solution
  4. Probabilities in Knockout
  5. Calories in, calories out
  6. No, diversity does not generally trump ability
  7. The discreet hotel manager
  8. Probabilistic Tic-Tac-Toe solution
  9. Probabilistic Tic-Tac-Toe
  10. Solving a corn maze
  11. Projectile motion puzzle solution
  12. Projectile motion puzzle
  13. Using a watch– or a stick– as a compass
  14. The Price Is Right puzzle solution
  15. The Price Is Right… sort of
  16. Reddit’s comment ranking algorithm revisited
  17. A coin puzzle revisited
  18. A coin puzzle
  19. allRGB: Hilbert curves and random spanning trees
  20. Pig puzzle solution
  21. Puzzle: A simple dice game
  22. When approximate is better than exact
  23. The odds of picking a “perfect” NCAA tournament bracket
  24. Computing positions and eclipses of the Sun and Moon

2013 21

  1. Another card puzzle
  2. An optimal stopping card game
  3. Floating-point equality: It’s worse than you think
  4. Sudoku Solver
  5. “Cold hit” DNA profiling
  6. Efficiency of card counting in blackjack (Part 3)
  7. Password protection of worksheets in Excel
  8. Efficiency of card counting in blackjack (Part 2)
  9. Efficiency of card counting in blackjack (Part 1)
  10. Probabilities in the game SET
  11. Probability Puzzle Solution
  12. Optimal angle on a swing
  13. Probability Puzzle
  14. Random number generation in Simulink
  15. Young Earth Creationism
  16. Analysis of Farkle
  17. Coincidences in random shuffling revisited
  18. Puzzle: Randomly shuffling songs in iTunes
  19. Visualizing Asteroid 2012 DA14
  20. Hunt the Wumpus
  21. Analysis of Shut the Box

2012 24

  1. Re-Analysis of Monopoly
  2. The Canonical Pirate Puzzle
  3. If the Earth Had Two Moons
  4. Kinect skeleton tracking with Visual Python
  5. The Value of Mathematics Revisited
  6. Blackjack CA optimization as a Steiner tree problem
  7. Ant in the Desert
  8. Hitting a Golf Ball on the Moon: Solution
  9. Hitting a Golf Ball on the Moon
  10. Security of the Android Pattern Lock
  11. IBM Research Ponder This: July 2012 Puzzle
  12. Wait, what?
  13. Python on Android
  14. How GoTo Telescopes Work
  15. The Hunger Games: Follow-up
  16. More Mathematics in The Hunger Games
  17. It’s Turtles All the Way Down
  18. Home Schooling in the U.S.
  19. Why fewer decks are better for the blackjack player
  20. Blackjack and number of decks
  21. The Alias Method and Double Precision
  22. Using a Watch as a Compass
  23. Light Bulb Puzzle Solution
  24. Dropping Light Bulbs (or Eggs): An Interview Puzzle Twist

2011 38

  1. Secret Santa Revisited
  2. Holiday Puzzles
  3. The Ultimate Answer to the Ultimate Question
  4. Polygon Puzzle
  5. Analysis of the Memory Game
  6. Use Your Head
  7. Everything Is Possibly Wrong
  8. If the Earth Were a Cube
  9. Solving the 2x2x2 Rubik’s Cube
  10. How to Solve It
  11. Expectation Isn’t Everything
  12. Blackjack and pair splitting
  13. The food tastes pretty good to me…
  14. Representing Permutations
  15. Unlocking Boxes: A Prisoner Puzzle Variant
  16. Re-Measuring Morton
  17. Reddit’s comment ranking algorithm
  18. Generalizing Fitch Cheney’s Five-Card Trick
  19. Prisoner Puzzles
  20. A Prisoner Puzzle
  21. CAPTCHAs revisited
  22. Calculating Days of the Week (In Your Head)
  23. Don’t Have Faith In Science
  24. Analysis and a variant of “The Premo” card trick
  25. Card Shuffling: You’re Not Done Yet
  26. Was the Moon Super or Not?
  27. The Job Interview Question, Part 2
  28. The Job Interview Question, Part 1
  29. Geomagnetism, Runways, and Sea Turtles
  30. Counting Connections
  31. Happy Valentine’s Day
  32. Card Puzzle, Part 2
  33. Card Puzzle, Part 1
  34. Looking Up
  35. It Does, In Fact, Take Two to Tango
  36. Yet Another Rubik’s Cube
  37. Fractional Representation
  38. Is the Earth Like a Billiard Ball Or Not?

2010 35

  1. Why Multiple Checkout Lines Are Not All Bad
  2. Yankee Swapping Secretaries
  3. God Is a Fitness Function
  4. Robot Simulator and Turtle Graphics, Revisited
  5. A Robot Simulator Using VPython
  6. Flocking Boids and Emergent Behavior
  7. Fun with Dimensional Analysis
  8. Challenging Unstated Assumptions
  9. Teaching When No One Is Watching
  10. Deranged Secret Santa
  11. Birthdays, coincidences, and cryptography
  12. Visual Python
  13. Cops and Robbers
  14. More voting: not unanimous, just involved
  15. The Uncanny Valley
  16. Gerrymandering: you know it when you see it?
  17. Carcassonne update
  18. The Value of Mathematics
  19. Mouse picking
  20. The Cube of Rubik
  21. Carcassonne and intellectual property
  22. Reality TV, the Olympics, and Voting
  23. What makes a board game fun?
  24. Statistics of Deadly Quarrels
  25. Matters of death and life
  26. Math for the 4th of July
  27. CAPTCHAs (and reCAPTCHAs)
  28. Turing’s Law of Robotics?
  29. Skyboxes and Xboxes
  30. Remembering Martin Gardner
  31. Sabermetrics
  32. Miracles happen every day
  33. Science and Faith: Discovery or Invention?
  34. Pente from the Apple // to today
  35. Hello World