With the new capability for players to submit times "over the air" for the same puzzle from their tablet or Smartphone, we're starting to see lots of different times coming in!

You might notice that the time you end up with on the board isn't the same as the time that you posted... and here's why...

We came up with a way that we thought would fairly compare scores. Firstly, everyone will be comparing times for the same puzzle for the same level.

Aside from the pure time it took you to complete the puzzle, we'll add on extra time to make things fair:

Auto Pencilmarks

Using Auto Pencilmarks makes easy puzzles trivial, and is simply a mechanical time-saver. We reckon that it saves about 3 minutes on pretty much any puzzle, so you'll get 3 minutes added on to your time if you've used Auto-Pencilmarks at any point in the puzzle.

Hints

Hints currently have a time-cost of 15 seconds per hint. If you press hint several times to see the complete solution, that might cost you 45 or 60 seconds. If you just tap once and it highlights the area, and that's enough for you, it only cost 15 seconds. Try to get through using as few hints as possible!

Mistakes

The penalty per mistake depends on the game level, for mistakes that are flagged (or forbidden) :

Mistakes are even more interesting... If you are using "flag" or "forbid" for mistakes, then if you make an incorrect choice (or a guess, the difference is academic!), it will tell you that it is incorrect, which is often enough to tell you what the right value should be. In fact, getting an answer in this way is often enough for you to bypass a whole load of pain in the harder puzzles. (Tricky and above.)

If you're not using Flag or Forbid, then mistakes won't carry any time cost (or penalty) since you get no potential advantage from making mistakes.

On easy levels, mistakes don't make a huge amount of difference. On later levels, they really help. Of course, there's no way to tell between a "slip" and an error of judgement, but since both can lead to a much lower time, we have to count them the same. (If you don't want slips or errors of judgement to count against you, don't use error flagging - if your logic is good, this won't affect you at all!)

Tips

Some quick tips to help you get towards the top of the table:

• Don't use auto-pencilmarks for the easiest puzzles - the three minute penalty for easy puzzles is often longer than the time it might take you to solve!
• Work carefully - avoid making mistakes from a slip of the finger (or stylus)!
• Don't ask for hints unless you're really stuck - and try to just use the first hint that displays an area to concentrate on, which will only cost 15s!
• If you're able to, spot naked & hidden pairs and triples and use them whenever you can, with practise they are easy to find and often unlock puzzles much faster than rigorous searching through every row, column and block!

Cheating

We realise that there are dozens of ways to cheat - such as solving it offline - or even looking for the solution to that puzzle on the Sudoku Of The Day website...

There aren't any prizes for getting the top time, so there's nothing to gain by cheating in this way. We're hoping that people play the game honestly and enjoy submitting their scores. And, if you spot a time that you think is obviously cheating, the best thing to do is to just ignore it!

For more information on the game, you can visit our dedicated companion website SudokuOfTheDay.com.