Scanraid Grader
On a recent trip to my favorite web-based sudoku tool, Scanraid's sudoku solver, I noticed that they had added a new rating system to the site. I felt it was worth taking a trip down memory lane of some famous "classics" I've solved, and some that aren't so famous, to see what kind of numbers Scanraid would now give them.
WSC1 - Final Puzzle - 211 (Diabolical)
First Nikoli.com sudoku championship puzzle (from which I am currently wearing one dark blue t-shirt) - 200 (Diabolical)
52 second sudoku - 7 (Gentle/Very Easy Grade)
USSC puzzles:
Round 1 - Q - 169 (Diabolical)
Q (minus upper-right clues as per onigame's blog posting of original form) - 427 (Diabolical)
Round 2 - Vortex - 74 (Moderate)
Round 3 - Independence Day - 63 (Moderate)
Final Expert Puzzle (Rays) - 189 (Diabolical)
Stanford Film Puzzles:
1 - SU Doku - (2'11") - 43 (Gentle/Easy Grade)
2 - (58") - 4 (Gentle/Very Easy Grade)
3 - (2'33") - 12 (Gentle/Very Easy Grade)
4 - (1'43") - 57 (Gentle/Easy Grade)
5 - (3'10") - 124 (Moderate Grade)
6 - (3'36") - 125 (Moderate Grade)
7 - (3'25") - 85 (Tough Grade)
8 - (2'9") - 125 (Tough Grade)
WSC3 Puzzles (Round 2 - Classics):
1 (15 points) - 12 (Gentle/Very Easy Grade)
2 (15 points) - 21 (Gentle/Very Easy Grade)
3 (25 points) - 43 (Gentle/Easy Grade)
4 (25 points) - 54 (Moderate Grade)
5 (30 points) - 98 (Tough Grade)
6 (35 points) - 72 (Tough Grade)
7 (40 points) - 133 (Tough Grade)
8 (45 points) - 127 (Moderate Grade)
9 (50 points) - 126 (Tough Grade)
10 (55 points) - 165 (Diabolical Grade)
11 (55 points) - 136 (Tough Grade)
12 (60 points) - 158 (Tough Grade)
WS3 Classic Playoffs:
1 (GOA - 2'26") - 68 (Moderate Grade)
2 ("Twist X" - 3'1") - 47 (Moderate Grade)
3 (Bullseye - 2'33") - 47 (Moderate Grade)
4 (Boxes aka "This one goes to 11" - 8'08") - 378 (Diabolical Grade)
For reference: Easter Monster - 0 - (cannot be graded - "Insufficient logical strategies are known")
AI Escargot - 0 - (cannot be graded - "Insufficient logical strategies are known")
So, while I really strongly agree with most of these numbers, using those numbers to estimate a human's solving times is clearly difficult. The puzzle difficulty ranking of Round 2 at WSC3 is pretty clean, all things considered. The match-up between the different championship puzzles is interesting. We knew the "11" puzzle from WSC3 was very hard, but it turns out the bare Q, without the extra two helper digits, would be slightly harder. Neither seems particularly fair.
WSC1 - Final Puzzle - 211 (Diabolical)
First Nikoli.com sudoku championship puzzle (from which I am currently wearing one dark blue t-shirt) - 200 (Diabolical)
52 second sudoku - 7 (Gentle/Very Easy Grade)
USSC puzzles:
Round 1 - Q - 169 (Diabolical)
Q (minus upper-right clues as per onigame's blog posting of original form) - 427 (Diabolical)
Round 2 - Vortex - 74 (Moderate)
Round 3 - Independence Day - 63 (Moderate)
Final Expert Puzzle (Rays) - 189 (Diabolical)
Stanford Film Puzzles:
1 - SU Doku - (2'11") - 43 (Gentle/Easy Grade)
2 - (58") - 4 (Gentle/Very Easy Grade)
3 - (2'33") - 12 (Gentle/Very Easy Grade)
4 - (1'43") - 57 (Gentle/Easy Grade)
5 - (3'10") - 124 (Moderate Grade)
6 - (3'36") - 125 (Moderate Grade)
7 - (3'25") - 85 (Tough Grade)
8 - (2'9") - 125 (Tough Grade)
WSC3 Puzzles (Round 2 - Classics):
1 (15 points) - 12 (Gentle/Very Easy Grade)
2 (15 points) - 21 (Gentle/Very Easy Grade)
3 (25 points) - 43 (Gentle/Easy Grade)
4 (25 points) - 54 (Moderate Grade)
5 (30 points) - 98 (Tough Grade)
6 (35 points) - 72 (Tough Grade)
7 (40 points) - 133 (Tough Grade)
8 (45 points) - 127 (Moderate Grade)
9 (50 points) - 126 (Tough Grade)
10 (55 points) - 165 (Diabolical Grade)
11 (55 points) - 136 (Tough Grade)
12 (60 points) - 158 (Tough Grade)
WS3 Classic Playoffs:
1 (GOA - 2'26") - 68 (Moderate Grade)
2 ("Twist X" - 3'1") - 47 (Moderate Grade)
3 (Bullseye - 2'33") - 47 (Moderate Grade)
4 (Boxes aka "This one goes to 11" - 8'08") - 378 (Diabolical Grade)
For reference: Easter Monster - 0 - (cannot be graded - "Insufficient logical strategies are known")
AI Escargot - 0 - (cannot be graded - "Insufficient logical strategies are known")
So, while I really strongly agree with most of these numbers, using those numbers to estimate a human's solving times is clearly difficult. The puzzle difficulty ranking of Round 2 at WSC3 is pretty clean, all things considered. The match-up between the different championship puzzles is interesting. We knew the "11" puzzle from WSC3 was very hard, but it turns out the bare Q, without the extra two helper digits, would be slightly harder. Neither seems particularly fair.