The New Sudoku Players' Forum

[champagne]

Setting up files for users of potential hardest puzzles I got a surprising result.
The solution grid 1339521744 has 49 puzzles rating skfr >=10.5
All these sudokus have 23 clues and a skfr EP >=10.5

For such puzzles, we have no expand reduction with my process, so we end with this list

Hidden Text: Show

Code: Select all

1...567......8..3.6..2.74.....64.5..5.............5.17..2......7....41...9.....7. ED=11.3/11.3/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......7....41...9.....7. ED=11.1/11.1/2.6
1....67......8..3.6..2.745....64.5..5.............5.17..2......7....41...9.....7. ED=11.0/11.0/2.6
1....67......8..3.6..2.745....64.5..5.............5.17..2.....57....41...9....... ED=11.0/11.0/2.6
1....67.9....8..3.6....745....64.5..5.............5.17..2......7....41...9.....7. ED=11.0/11.0/2.6
1....67.9....8..3.6....745....64.5..5.............5.17..2......7....41...9..6.... ED=11.0/11.0/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......7....41...9..6.... ED=11.0/11.0/2.6

1....67......8..3.6..2.745....64.5..5.............5.17..2......7....41...9..6.... ED=10.9/10.9/2.6
1....67......8..3.6..2.745....64.5..5.............5.17..2......7....41...91...... ED=10.9/10.9/2.6
1....67.9....8..3.6....745....64.5..5.............5.17..2......7....41...91...... ED=10.9/10.9/2.6
1....67.9....8..3.6....745....64.5..5.............5.17..2.....57....41...9....... ED=10.9/10.9/2.6
1....67.9..7.8..3.6....745..7.64.5..5.............5.17..2......7....41...9....... ED=10.9/10.9/2.6
1...567......8..3.6..2.74.....64.5..5.............5.17..2......7....41...9..6.... ED=10.9/10.9/2.6
1...567......8..3.6..2.74.....64.5..5.............5.17..2......7....41...9.5..... ED=10.9/10.9/2.6
1...567......8..3.6..2.74.....64.5..5.............5.17..2......7....41...91...... ED=10.9/10.9/2.6
1...567....7.8..3.6..2.74...7.64.5..5.............5.17..2......7....41...9....... ED=10.9/10.9/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......7....41...9.5..... ED=10.9/10.9/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......7....41...91...... ED=10.9/10.9/2.6
1...567.9..7.8..3.6....74...7.64.5..5.............5.17..2......7....41...9....... ED=10.9/10.6/2.6

1....67.9....8..3.6....745....64.5..5.............5.17..2......7.5..41...9....... ED=10.8/10.8/2.6
1....67.9....8..3.6....745....64.5..5.............5.17..2......76...41...9....... ED=10.8/10.8/2.6
1....67.9....8..3.6....745....64.5..5..........4..5.17..2......7....41...9....... ED=10.8/10.8/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......7.5..41...9....... ED=10.8/10.5/2.6
1....67......8..3.6....745....64.5..5.............5.17..2......7....412..9.....7. ED=10.5/10.5/2.6
1....67......8..3.6....745....64.5..5.............5.17..2......7...941...9.....7. ED=10.6/10.6/2.6
1....67......8..3.6....745....64.5..5.............5.17..2......7...941...9..6.... ED=10.7/10.7/2.6
1....67......8..3.6....745....64.5..5.............5.17..2......7...941...91...... ED=10.7/10.7/2.6
1....67......8..3.68.2.74.....64.5..5.............5.17..2......7....41...9.....7. ED=10.7/10.7/2.6
1....67......8..3.6..2.745....64.5..5.............5.17..2......7.5..41...9....... ED=10.6/10.6/2.6
1....67......8..3.6..2.745....64.5..5.............5.17..2......76...41...9....... ED=10.6/10.6/2.6
1...567......8..3.6....74.....64.5..5.............5.17..2......7...941...9.....7. ED=10.6/10.6/2.6
1...567......8..3.6....74.....64.5..5.............5.17..2......7...941...91...... ED=10.6/10.6/2.6
1...567......8..3.6..2.74.....64.5..5..........4..5.17..2......7....41...9....... ED=10.6/10.6/2.6
1...567.9....8..3.6....74.....64.5..5.............5.17..2......76...41...9....... ED=10.6/10.6/2.6
1....67......8..3.6....745....64.5..5.............5.17..2.....57....412..9....... ED=10.5/10.5/2.6
1....67......8..3.6..2.745....64.5..5..........4..5.17..2......7....41...9....... ED=10.5/10.5/2.6
1....67......8..3.68..374.....64.5..5.............5.17..2......7....41...9.....7. ED=10.5/10.5/2.6
1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...9.....7. ED=10.5/10.5/2.6
1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...9..6.... ED=10.5/10.5/2.6
1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...9.5..... ED=10.5/10.5/2.6
1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...91...... ED=10.5/10.5/2.6
1...567......8..3.6....74.....64.5..5.............5.17..2......7...941...9..6.... ED=10.5/10.5/2.6
1...567......8..3.6..2.74.....64.5..5.............5.17..2......7.5..41...9....... ED=10.5/10.5/2.6
1...567......8..3.6..2.74.....64.5..5.............5.17..2......76...41...9....... ED=10.5/10.5/2.6
1.3..67......8..3.6...374.....64.5..5.............5.17..2......7....41...9.....7. ED=10.5/10.5/2.6
1.3..67......8..3.6...374.....64.5..5.............5.17..2......7....41...9..6.... ED=10.5/10.5/2.6
1.3..67......8..3.6...374.....64.5..5.............5.17..2......7.5..41...9....... ED=10.5/10.5/2.6
1.3..67......8..3.6...374.....64.5..5.............5.17..2.....57....41...9....... ED=10.5/10.5/2.6
1.3..678.....8..3.6....74.....64.5..5.............5.17..2......7....41...9.....7. ED=10.5/10.5/2.6

I am very busy these days, but I think this is worth to be studied by experts.
What can explain all these high ratings.
I think that all of them have a JE 2389 base r4c45, with a poor effect, something else common to all of them must be

[champagne]

I had a look at one grid, I see a double JE, so a puzzle easy to solve

[RSW]

I looked at the last 10 in the list, and all of these have JE's, and then LCLSTE.

[champagne]

I looked at the last 10 in the list, and all of these have JE's, and then LCLSTE.

Thanks for your check

All these sudokus have 20 common clues out of 23 and have the same solution grid. They likely all have the double JE 2389 r4c89;r6c45

seen by a player, one is enough, but I don't have the code to do that.

The rating 11.3 could be slightly harder after the effect of the conjugated JEs

[ghfick]

All 49 puzzles have the Double JE.
Gordon

[blue]

The double JE is also present in the (32 solution) puzzle formed by the common clues.
After the (DJE) eliminations, all but three of the puzzles, solve with naked & hidden singles.

These 3 need naked pairs too:

Code: Select all

1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...9..6.... ED=10.5/10.5/2.6
1....678.....8..3.68...74.....64.5..5.............5.17..2......7....41...91...... ED=10.5/10.5/2.6
1.3..67......8..3.6...374.....64.5..5.............5.17..2......7....41...9..6.... ED=10.5/10.5/2.6

[ghfick]

Code: Select all

+--------------+----------------+----------------+
| 1   238 389  | 4    2359 6    | 7   2589 289   |
| 4   57  57   | 1    8    29   | 29  3    6     |
| 6   238 389  | 239  2359 7    | 4   2589 1     |
+--------------+----------------+----------------+
| 29  378 378  | 6    4    1    | 5   289  2389  |
| 5   16  16   | 29   7    38   | 38  4    29    |
| 29  348 348  | 2389 239  5    | 6   1    7     |
+--------------+----------------+----------------+
| 38  14  2    | 57   16   389  | 389 67   45    |
| 7   56  56   | 2389 239  4    | 1   289  2389  |
| 38  9   14   | 57   16   238  | 238 67   45    |
+--------------+----------------+----------------+


[champagne]

here are the 2 next solution grids with similar high count of sudokus that my process could not reduce

solution grid 4339735919

Hidden Text: Show

Code: Select all

12....7....7....36....7.......5..........8.....6.173...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.......5..........8.....6.173...4.....9...1.246....2.3.14.   23
12....7....7....36....7.......5..........8.....6.173...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7.......5..........8.....621.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.......5..........8.....621.3...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7.......5..........8....8621.3...4.....9...1.2.67...2.3.1..   23
12....7....7....36....7.......5.....7....8.....6.1.3...4.....9...1.246....2.3.14.   23
12....7....7....36....7.......5....7.....8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.......5....7.....8.....6.1.3...4.....9..91.2.6....293.1..   23
12....7....7....36....7.......5....7.....8.....6.1.3...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7.......5....7.....8.....6.1.35..4.....9...1.2.67...2.3.1..   23
12....7....7....36....7.......5...6......8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.......5...6......8.....6.1.3...4.....9...1.246....2.3.14.   23
12....7....7....36....7.......5...6......8.....6.1.3...4.....9..91.2.6....293.1..   23
12....7....7....36....7.......5.3........8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.......5.3........8.....6.1.3...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7.....1.5..........8.....6.1.3...4.....9...1.2.6....293.14.   23
12....7....7....36....7.....1.5..........8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7.....1.5..........8.....6.1.3...4.....9...1.246....2.3.14.   23
12....7....7....36....7.....1.5..........8.....6.1.3...4.....9..91.2.6....293.1..   23
12....7....7....36....7.....1.5..........8.....6.1.3...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7.....1.5..........8.....6.1.35..4.....9...1.2.67...2.3.1..   23
12....7....7....36....7.....1.5..........8....86.1.3...4.....9...1.2.67...2.3.1..   23
12....7....7....36....7....2..5..........8.....6.1.3...4.....9...1.2.6....293.14.   23
12....7....7....36....7....2..5..........8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12....7....7....36....7....2..5..........8.....6.1.3...4.....9...1.246....2.3.14.   23
12....7....7....36....7....2..5..........8.....6.1.3...4.....9..91.2.6....293.1..   23
12....7....7....36....7....2..5..........8.....6.1.3...4.....9.5.1.2.67...2.3.1..   23
12....7....7....36....7....2..5..........8.....6.1.35..4.....9...1.2.67...2.3.1..   23
12....7....7....36....7....2..5..........8....86.1.3...4.....9...1.2.67...2.3.1..   23
12....7....7....36.6..7.......5.....7....8.....6.1.3...4.....9...1.2.6...72.3.1.8   24
12....7....7....36.6..7....2..5..........8.....6.1.3...4.....9...1.2.6...72.3.1.8   24
12....7....71...36....7.......5..........8.....6.1.3...4...1.9...1.2.67...2.3.1.8   24
12....7....71...36....7.......5..........8.....6.1.3...4...1.9.5.1.2.67...2.3.1..   24
12....7....71...36....7.......5..........8.....6.1.35..4...1.9...1.2.67...2.3.1..   24
12....7....71...36.6..7.......5..........8.....6.1.3...4...1.9...1.2.6...72.3.1.8 25
12...67....7....36....7.......5..........8.....6.1.3...4.....9...1.2.67...2.3.1.8   23
12...67....7....36....7.......5..........8.....6.1.3...4.....9.5.1.2.67...2.3.1..   23

solution grid 5157451959

Hidden Text: Show

Code: Select all

1...5.7.........6...9....51..8......5...6...7.4...2.3.3...1..7..1...83..8...37.16   25
1...5.7.........6...9....51..8......5...6...7.4...2.3.3...1..7..1...83..89..3..16   25
1...5.7.........6...9....51..8......5...6...7.4...2.3.3..91..7..1...83..8...3..16   25
1...5.7.........6...9....51..8......5...6...794...2.3.3...1..7......83..8...37.16   25
1...5.7.........6...9....51..8......5...6...794...2.3.3...1..7......83..8.4.3..16   25
1...5.7.........6...9....51..8......5...6...794...2.3.3...1..7....6.83..8...3..16   25
1...5.7.........6...9....51..8......5...6...794...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...9....51..8......5...64..7.4...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...9....51..8......53..6...7.4...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...9....51..83.....5...6...7.4...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...9..3.51..8......5...6...7.4...2.3.3...1..7......83..8...37.16   25
1...5.7.........6...9..3.51..8......5...6...7.4...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...9..3.51..8......5...6...7.4...2.3.3.2.1..7......83..8...3..16   25
1...5.7.........6...9..3.51..8......5...64..7.4...2.3.3...1..7......83..8...3..16   25
1...5.7.........6...97...51..8......5...6...7.4...2.3.3...1..7......83..8...37.16   25
1...5.7.........6...97...51..8......5...6...7.4...2.3.3...1..7..1...83..8...3..16   25
1...5.7.........6...97...51..8......5...64..7.4...2.3.3...1..7......83..8...3..16   25
1...5.7.........63..9....51..83.....5...64..7.4...2...3...1..7......83..8...3..16   25
1...5.7.........63..9..3.51..8......5...6...7.4...2...3...1.87..1...83..8...3..16   26
1...5.7...5.....6...9....51..8......5...6...7.4...2.3.3...1..7......83..8...37.16   25
1...5.7...5.....6...9....51..8......5...6...7.4...2.3.3...1..7......83..89..3..16   25
1...5.7...5.....6...9....51..8......5...6...7.4...2.3.3..91..7......83..8...3..16   25
1...5.7...5.....6...9....51..8......5...6...794...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....6...9....51..8......5...64..7.4...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....6...9....51..8......53..6...7.4...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....6...9....51..83.....5...6...7.4...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....6...9..3.51..8......5...6...7.4...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....6...9..3.51..83.....5...6...7.4...2...3...1..7......83..8.4.3..16   26
1...5.7...5.....6...97...51..8......5...6...7.4...2.3.3...1..7......83..8...3..16   25
1...5.7...5.....63..9....51..83.....5...6...7.4...2...3...1..7......83..8...3..16   25
1...5.7...57....6...9....51..8......5...6...7.4...2.3.3...1..7......83..8.4.3..16   26
1...5.7..4......6...9....51..83.....5...6...7.4...2.3.3...1..7......83..8.4.3..16   26
1...5.7..4......6...9..3.51..8......5...6...7.4...2.3.3...1..7......83..8.4.3..16   26
1...5.7..4......63..9....51..83.....5...6...7.4...2...3...1..7......83..8.4.3..16   26
1...567.........6...9....51..8......5...6...7.4...2.3.3...1..7......83..8...37.16   25
1...567.........6...9....51..8......5...6...7.4...2.3.3...1..7..1...83..8...3..16   25
1...567.........6...9....51..8......5...64..7.4...2...3...15.7......83..8...3..16   25
1...567...5.....6...9....51..8......5...6...7.4...2.3.3...1..7......83..8...3..16   25
1.3.5.7.........63..9....51..8......5...6...7.4...2.3.....1..7..1...8...89..37.16   26