Escargot
In late November 2006, a Finnish applied mathematician, Arto Inkala, claimed to have created the world's hardest Sudoku.
"I called the puzzle AI Escargot, because it looks like a snail. Solving it is like an intellectual culinary pleasure. AI are my initials," he said.
"Escargot demands those tackling it to consider eight casual relationships simultaneously, while the most complicated variants attempted by the public require people to think of only one or two combinations at any one time", Inkala said.
This puzzle is available in the drop down list of examples in the
Sudoku Solver. The solver cannot currently solve it, however, using the logical strategies at it's desposal. The brute force "Solution Count" can find the solution but such a method is less interesting than a logical solve route.
Escargot recieved a good deal of publicity in newspapers around the world.
Load Escargot
Comments
Comments TalkTuesday 16-Nov-2021
... by: S3ven_Six
This is definitively either not the real Escargot, or I found a much harder one.I was able to spot a hidden 2468 quadruple in column 7, forcing a 17 pair that straight up solved the board. There are several other spots that if u just find 1 single digit, the entire board solves itself.
This is a more difficult puzzle that didn't take me 10 minutes to solve, but 2 hours of multicoloring, and contradiction testing, etc. -- with 2 times of straight up bifurcation.
https://f-puzzles.com/?id=yhtyjrzr
Friday 1-Aug-2014
... by: JPF Naperville, IL
The Escargot puzzle at aisudoku.com does not have a 1 at H3. Your solver added that viafinned swordfish? Please clarify.
Saturday 2-Jun-2012
... by: Leren
Escargot is harder than Andrew's Weekly unsolvables (except for no 49) but only requires first order forcing chain logic to solve, so it's not in the hardest class of puzzle. The 2010 puzzle by the same creator was similar but slightly easier.Tuesday 22-Sep-2009
... by: lihsiaotung
"Escargot demands those tackling it to consider eight casual relationships simultaneously, while the most complicated variants attempted by the public require people to think of only one or two combinations at any one time", Inkala saidbut I solved Escargot through considering seven casual relationships simultaneously with my solver. Maybe Escargot was not the most difficult Sudoku puzzle,I think.