PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Clue Symmetry and Logic (for patron Phleb)

Author/Opus: This is the 122nd puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Sudoku rules. Also, identical digits cannot be in diagonally-adjacent cells.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 7:00, Master = 12:00, Expert = 24:00

Solution: PDF

Note: Follow this link for other variations of Sudoku and this link for classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on.

While my relocation back to the San Francisco area and new job commitments limited our posts in 2015 compared to other years, we still had almost 200 puzzle posts in 2015 and many amazing puzzles. Today we will be presenting the “Best of 2015” selections, using data from the FAVE button at the bottom of each post. Because of a variable number of solvers over the year (particularly after the hiatus), the selection process included raw FAVE counts, FAVE/solver ratios, and internal discussions when those values brought up ties. We start with our BEST SUDOKU.

This past year, the best Sudoku puzzles featured either arithmetic constraints or series-based constraints. One of our best sudoku featured both, namely this Arrow/Thermo-Sudoku by Prasanna Seshadri.

Another highly rated puzzle was this Killer Sudoku by Serkan Yürekli.

The highest ratings though went to two Thermo-Sudoku. Both were puzzles originally created for the magazines Will Shortz’s Sudoku and Sudoku Spectacular where we regularly contribute puzzles. But these were kept for this site due to their unique look and solving feel.

On the easier end was this very fun Thermo-Sudoku from guest contributor Ashish Kumar.

And on the harder end was this self-titled “THERMO” puzzle from Dr. Sudoku.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Clue Symmetry and Logic (Originally for 2015 Arlington Puzzle Festival — playoff puzzle)

Author/Opus: This is the 234th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Answer String: Enter the 3rd row from left to right, followed by a comma, followed by the 5th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 2:30, Master = 4:15, Expert = 8:30

Solution: PDF

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Three Ring Circus (Originally for 2015 Arlington Puzzle Festival)

Author/Opus: This is the 233rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 9th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 2:45, Master = 4:30, Expert = 9:00

Solution: PDF

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diagonal Series (Originally for 2015 Arlington Puzzle Festival)

Author/Opus: This is the 232nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Answer String: Enter the 2nd row from left to right, followed by a comma, followed by the 5th row from left to right.

Time Standards (highlight to view): Grandmaster = 2:00, Master = 4:15, Expert = 8:30

Solution: PDF

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Fan (Originally for 2015 Arlington Puzzle Festival)

Author/Opus: This is the 231st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules.

Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 2:15, Master = 3:15, Expert = 6:30

Solution: PDF

Note: Follow this link for other classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on. More classic Sudoku puzzles can be found in The Art of Sudoku, The Art of Sudoku 2 and in our beginner-friendly collection Intro to GMPuzzles by Serkan Yürekli.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: ¿¡¿Dos Unos en Una Fila?!? (“Translated” from a puzzle by Thomas Snyder on the 3rd SudokuCup

Author/Opus: This is the 4th puzzle from guest contributor Bryce Herdt.

Rules: Standard Sudoku rules. Also, in the cells with red letters, a number can only be entered if it contains that letter when spelled out in Spanish.

Answer String: Enter the 1st column from top to bottom, followed by a comma, followed by the 9th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 7:30, Master = 12:00, Expert = 24:00

Solution: PDF

Note: Follow this link for other variations of Sudoku and this link for classic Sudoku. If you are new to this puzzle type, here are our easiest Sudoku to get started on.

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Digit Series and Clue Symmetry

Author/Opus: This is the 227th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Additionally, some numbered arrows outside the grid indicate the sum of the digits along that diagonal path. (Digits can repeat along a diagonal sum.)

Note: No answer strings or timing here (honor system for when you solve it). I’m simply posting some “examples” I wrote as the Sudoku Grand Prix coordinator. Apparently some common variants aren’t common enough….

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Diagonals

Author/Opus: This is the 226th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Additionally, there are two overlapping classic sudoku grids, and both must have valid solutions.

Note: No answer strings or timing here (honor system for when you solve it). I’m simply posting some “examples” I wrote as the Sudoku Grand Prix coordinator. Apparently some common variants aren’t common enough….

Solution: PDF

PDF

or solve online (using our beta test of Penpa-Edit tools)

Theme: Digit Series and Clue Symmetry

Author/Opus: This is the 225th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Sudoku rules. Additionally, some edges are marked with the sums of the digits in the adjacent cells.

Note: No answer strings or timing here (honor system for when you solve it). I’m simply posting some “examples” I wrote as the Sudoku Grand Prix coordinator. Apparently some common variants aren’t common enough….

Solution: PDF