PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Theme: Digit Series

Author/Opus: This is the 224th puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: (Standard Balance Loop rules.) Draw a single, non-intersecting loop that passes through all circled cells. All white circles must have equal segment lengths on both sides of the circle before turning. All black circles must have unequal segment lengths on both sides of the circle before turning. Numbers indicate the sum of the segment lengths on both sides of the circle.
Also, see this example:

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma. This example has the key “11,311”.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 8:00, Expert = 16:00

Solution: PDF

Note: Follow this link for other Balance Loops.

PDF

or solve online (using our beta test of Penpa-Edit tools; in default linex mode: left-click+drag draws line, right click marks X on edge)

Theme: 24-7-365

Author/Opus: This is the 2nd puzzle from guest contributor Bryce Herdt (the 1st was his winning submission for our first hidden contest).

Rules: Draw a single loop in the grid which may cross itself orthogonally, but otherwise does not touch or retrace itself. The clue numbers to the left/right of the rows indicate the number of squares visited by the nearest section of the loop that travels horizontally in the rows. The clue numbers to the top/bottom of the columns indicate the number of squares visited by the nearest section of the loop that travels vertically in the columns.

Also, see this example:

Answer String: Enter the number of empty squares for each row from top to bottom, followed by a comma, and then the number of turns for each row from top to bottom. This example has the key “100000,422224”.

Time Standards (highlight to view): Grandmaster = 3:45, Master = 6:45, Expert = 13:30

Solution: PDF

Note: Follow this link for other Round Trip puzzles. Some more Round Trip puzzles can be found in the book Loop Variety Collection by Ashish Kumar and Murat Can Tonta.

PDF

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

Theme: Logical

Author/Opus: This is the 223rd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Yajilin rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 2:00, Master = 5:15, Expert = 10:30

Solution: PDF; a solution video is available here.

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

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Theme: Logical

Author/Opus: This is the 26th puzzle from our contributing puzzlemaster Tom Collyer.

Rules: Standard Masyu rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 1:00, Master = 1:30, Expert = 3:00

Solution: PDF

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

PDF

or solve online (using our beta test of Penpa-Edit tools in linex mode where left click+drag draws lines and right click marks X’s)

Theme: Clue Symmetry and Logic

Author/Opus: This is the 71st puzzle from our contributing puzzlemaster Serkan Yürekli.

Rules: Standard Castle Wall rules.

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 0:30, Master = 1:15, Expert = 2:30

Solution: PDF

Note: You can find other Castle Walls here.

(Note: This puzzle is at a Saturday+ difficulty, and is being posted today to mark the occasion of Prasanna’s birthday. Our regular “easy” puzzles will run on Tuesday and Wednesday this week.)

(View image directly for larger form.)

PDF

or solve online (using our beta test of Penpa-Edit tools in yajilin mode where left click shades squares, left click+drag draws lines and right click marks X’s; note that the default puzzle info is too long — even for an url shortener — so copy and paste all the text in this file into the “Load” option in the upper-right of the penpa-edit interface to access.)

Theme: 24 on 03/02/15

Author/Opus: This is the 73rd puzzle from our contributing puzzlemaster Prasanna Seshadri.

Rules: This puzzle combines four loop varieties commonly featured at GMPuzzles: Balance Loop (upper left), Yajilin (upper right), Castle Wall (lower left), and Masyu (lower right).

Draw a single, non-intersecting loop throughout all four quadrants. The loop may enter and exit the different quadrants as many times as needed.

The standard rules for each puzzle type are true for each quadrant, with these additional considerations:

Balance Loop: Use the entire length of segments (including parts of the segments that extend into an adjacent quadrant) when determining the balanced/unbalanced status of a circle clue.

Yajilin: The arrow clues refer only to shaded cells within the Yajilin quadrant. The loop must occupy all cells adjacent to a shaded cell, even in an adjacent quadrant.

Castle Wall: Number clues can see beyond the CW quadrant ONLY IF the line segment begins from a cell within the CW quadrant. (For example, if a segment starts in the rightmost column of the CW quadrant and goes three cells further to the right into the Masyu quadrant before turning, this segment would contribute 3 to the count of segments for that row.)

Masyu: Normal rules apply for white and black circles, but the path satisfying these rules can extend into an adjacent quadrant. (For example, a white circle can be passed through crossing a quadrant edge, provided it turns immediately on one side of the circle whether the turn is in the Masyu quadrant or in another quadrant.)

Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma.

Time Standards (highlight to view): Grandmaster = 30:00, Master = 55:00, Expert = 1:50:00

Solution: PDF

PDF

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

Theme: Self-Titled

Author/Opus: This is the 222nd puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Thermo-Sudoku rules.

Answer String: Enter the 8th row from left to right, followed by a comma, followed by the 3rd column from top to bottom.

Time Standards (highlight to view): Grandmaster = 9:45, Master = 12:45, Expert = 25:30

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Double Crossed

Author/Opus: This is the 5th puzzle from guest contributor Swaroop Guggilam.

Rules: Standard Arrow Sudoku rules.

Answer String: Enter the 4th row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 6:30, Master = 9:30, Expert = 19:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Fountain

Author/Opus: This is the 221st puzzle from Thomas Snyder, aka Dr. Sudoku.

Rules: Standard Arrow Sudoku rules.

Answer String: Enter the 5th row from left to right, followed by a comma, followed by the 9th row from left to right.

Time Standards (highlight to view): Grandmaster = 4:00, Master = 5:00, Expert = 10:00

Solution: PDF

Note: Follow this link for more Arrow Sudoku. If you are new to this puzzle type, here are our easiest Arrow Sudoku to get started on. More Arrow Sudoku puzzles can be found in The Art of Sudoku 2.

PDF

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

Theme: Level Thermometers

Author/Opus: This is the 2nd puzzle from guest contributor Ashish Kumar.

Rules: Standard Thermo-Sudoku rules.

Answer String: Enter the 2nd column from top to bottom, followed by a comma, followed by the 8th column from top to bottom.

Time Standards (highlight to view): Grandmaster = 3:00, Master = 5:30, Expert = 11:00

Solution: PDF

Note: Follow this link for more Thermo-Sudoku puzzles. If you are new to this puzzle type, here are our easiest Thermo-Sudoku to get started on. More Thermo-Sudoku puzzles can be found in The Art of Sudoku 2.