how to improve the ranking

So you’ve been playing a lot of time on your favourite Sudoku website, and and you want to climb the ranks of the leaderboard.

In most cases, the only way to do that is by achieving a better time.

How can you save time while solving a Sudoku online?

Mouse & Keyboard are your Pencil & Eraser. Use them both if you can. Many online solvers allow you to operate with right mouse button to quick up some operations. Others have keyboard shortcuts with which you can highlight numbers, select candidates, correct mistakes. Learn the interface, get acquainted with it, and use the tools you are given at your advantage.

While training, always time yourself. Almost every software does that for you, but if you are training on your desk you’ll need a stopwatch. Stop the clock right after you write down the last digit, and before you check the solution (that is because the computer automatically checks for the correctness in a fraction of a second.).

Timing also shows you directly your progresses and you’ll feel that training was worth doing.

Keep in mind how hard the Sudoku is. If you are solving an easy Sudoku don’t lose your time looking for a Hidden Triples and focus on Full Houses or Hidden Singles. If the grid is hard, you know that at least one advanced solving technique will be embedded in the solving process.

Knowing in advance what kind of challenge the Sudoku bears reduces the challenge level itself. use this information at your advantage.

Play rated games when you feel in the mood. You know best than everyone else. Are you a quicker solver in the morning? Or are your performances better before bedtime? Know your habits and your skills and prefer playing sudoku when you can be concentrated. Your results and your rank will improve greatly.

How to teach sudoku

You have been talking to a friend and you mentioned sudoku, of which you are expert in.

“Ah, but I don’t understand math”, this is the most common reply I got from my acquaintances.

A lot of people believe that since there are numbers on the grid, the game is about math.

Of course you know that’s not entirely true (but not entirely false, there is some involvement with the set theory…).

Eventually, you manage to have your friend sit next to you with an easy grid you found online.

Tip: pick a nice and easy sudoku! There’s plenty of grids available, so print out a simmetrical one. They are aesthetically pleasing and appealing.

Give him pencil and rubber: he is controlling the game. Use your own pencil to point at cells while explaining, but let him do the dirty work.

Explain that in every cell goes a number and that in every column, row, and region there must be all numbers from 1 thru 9. There is only one possible solution. That’s all.

First things first, point a cell and ask him which are the candidates for that cell. This is the basic to ensure he will be able to see if a mistake was done.

When he feels confident with this rule, but it happens that it is not enough to solve the sudoku, you can start explaining Full Houses and Last Digits. Address a column almost filled with numbers and ask something as easy as “Which of the numbers 1 to 9 are missing from Column 6?”

Help your friend to narrow down possibilities until you can enter another digit.

Now it’s time to teach the Hidden Single Technique: explain how rows and columns interact with each other. Use the pencil shafts to hide rows and columns as you explain the exclusion processes and show the leftover cells. Let him write the first numbers, and instruct him to double-check that the number does not appear again in the same row, cell, region.

In short time he will be able to solve a basic sudoku on his own, and hopefully learn new tricks to teach you in return.

Have fun in teaching sudoku!