Timing TBLR Sudoku, 3/26/10-4/8/10

When doing a Sudoku puzzle that’s relatively difficult, I sooner or later get to a place where I have to see if one of two alternatives leads to a contradiction. It raises the question of what constitutes a “lucky” guess. If I pick the alternative that is the correct one, I will solve the puzzle eventually, but I won’t find a contradiction. I may fill in quite a few numbers before realizing “Oh, this is the answer, isn’t it?” So a lucky guess from the standpoint of solving the puzzle eventually, isn’t necessarily a lucky guess from the standpoint of solving the puzzle quickly. Got that?

For those who are just tuning in, this is the seventh of a series of posts occuring once every two weeks. In these posts, I show how long it takes for me to do a Sudoku puzzle with the additional restriction of having to fill in the numbers in top-to-bottom, left-to-right order. Hence the name TBLR Sudoku.

Here are the times for the last two weeks, shown with the difference between the time and my personal best for that level of difficulty.

4/08/10 – 4-Star Sudoku in the Star-Tribune, top-to-bottom, left-to-right, 43:57, 15:05 slower than my personal best (PB+15:05).
4/07/10 – 3-Star, 36:55, PB+9:29
4/06/10 – 2-Star, 18:42, 1:42 improvement on my personal best (for a 2-Star) from 1/12/10
4/05/10 – 1-Star, 19:16, PB+1:03
4/04/10 – Didn’t do the puzzle
4/03/10 – Didn’t do the puzzle
4/02/10 – 5-Star, 45:46, PB+14:08
4/01/10 – 4-Star, 33:48, PB+4:56
3/31/10 – 3-Star, Fail
3/30/10 – 2-Star, 29:57, PB+9:33
3/29/10 – 1-Star, Fail
3/28/10 – Didn’t do the puzzle
3/27/10 – Didn’t do the puzzle
3/26/10 – 5-Star, Fail

Here are the updated personal bests:

1-Star: 18:13, 11/23/09
2-Star: 20:24, 1/12/10
3-Star: 27:26, 3/24/10
4-Star: 28:52, 2/18/10
5-Star: 31:38, 3/19/10
6-Star: 45:09, 2/13/10

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