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.