Sudoku Genius: 144 of the Most Fiendish Puzzles Ever Devised

I love very difficult Sudoku puzzles. And I find Mr. Sheldon's to be the very best. They are very difficult. But they are fair and honest. No gimmicks. No tricks. After being disappointed by many "self-proclaimed" hard puzzle books, I hit on an interesting idea. Since it is impossible to remember a puzzle's solution long after you've solved it, I thought that working these puzzles a second time would be as challenging as the first. So I bought another copy and started in. Much to my delight, the puzzles were as new and fresh as my first time through. So I've now purchased five copies of Genius and another five copies of Master Class. At one puzzle a day, I'm set for almost four years.

***** These puzzles are hard! "Sudoku Genius" is comprised of 144 hard puzzles, progressing from "Daunting" to "Tortuous" to "Merciless", on to "Harrowing", "Horrific", "Maddening", "Murderous", "Devastating", and finally "Deadly". I am just in "Merciless", the third level, and am really enjoying the challenge. There are some explanations of technique, which the author calls a "master class in advanced strategies"; it wasn't extremely useful for me, as I had known about the techniques already, but it was a nice refresher. There is only one puzzle per page, large grids, and altogether a great book for those who really want to be challenged. Obviously, this would be an impossible book for beginners, and highly frustrated for those who weren't ready for it. I bought it a year ago, and kept working from other books until I was ready. The author says that some of the puzzles require "trailing", which means that you DO have to guess, as there is not an logically identifiable solution. I have a problem with this. Fortunately, he lets you know which puzzles do require trailing, and there are only 30 of them. For those, I do cheat and look, as I think sudoku puzzles should not involve trailing. So I work around this feature of the book easily, and it doesn't detract from my fun. If you enjoy guessing and working a puzzle until you find out you've guessed incorrectly, then erasing everything, you won't have to do a work-around! Again, this really doesn't detract from the enjoyment of the book at all, though. Definitely recommended. *****

Tom Sheldon's second book of sudoku puzzles picks up where the introductory Big Sudoku Brain Workout leaves off, presenting 144 difficult puzzles graded in nine levels of difficulty, from Daunting to Deadly. Though these are described as "the most fiendish puzzles ever devised," they can all be solved (albeit on the second or third try, sometimes) by someone who has a basic knowledge of sudoku strategies and a good sense of logic. I began at the beginning, and either there is not much difference between the puzzles from the beginning to the end or I learned some tricks as I went along, but I found myself spending about the same amount of time on the puzzles at the end as at the beginning. Some of this may be because I gained greater practice using some of the techniques Sheldon includes in his helpful Master Class in Advanced Strategies, in the introduction. The author helpfully lists the thirty puzzles which require "trailing," his term for the technique that is sometimes necessary when groups of pairs block further progress in solving the puzzle. He makes a case for why this controversial technique (which involves choosing one of the numbers in a pair at random and following it throughout the puzzle) is still logical, not simply trial and error. He didn't convince me, but the puzzles could easily solved (especially when the first trial number was done on a Xerox copy). Several intriguing puzzles are completely missing one given number, but those turned out to be the most fun, and, as a rule not diffucult. Some not listed as requiring trailing did require it, and three or four listed as requiring trailing did not. and one puzzle, done by both my husband and me, turned out to have two completely different and correct solutions! The book is a good size, easy to carry in purse or portfolio, and the extra grids are helpful is you don't have a Xerox machine handy for copying the puzzle as you have worked on it to date. The puzzles are large, with plenty of room for listing options, and the answer key is at the end. Overall, this is a terrific collection for the sudoku puzzler who doesn't want to spend all day on one puzzle, a collection of challenging puzzles which are still "do-able." n Mary Whipple

Challenging, which is awesome! Also it is printed on great paper that is good for erasing pencil without awful smudges and the puzzles are large enough for even my bubbly writing!

Most Sudoku books have puzzles from easy to hard; this book contains all difficult puzzles, taking you through the nine "circles" of Sudoku Hell. The levels are Daunting, Tortuous, Merciless, Harrowing, Horrific, Maddening, Murderous, Devastating, and Deadly. The introduction contains a very brief explanation of the basic concepts and methods. Then, for the seasoned Sudoku addict, there are 15 pages of "expert methods" which includes new strategies that I hadn't seen before. Each puzzle is about 4.5 X 4.5 inches, allowing plenty of room to write in the squares. The paper quality is good, allowing the maximum usage of your eraser without smudging and thick enough to let you erase over and over . . . This is a great book for the person who has already mastered the easy to medium puzzles, and finds most of the hard puzzles too easy. If you want to learn new tips and experience a challenge, this is a great book!