In the world of logic, there is no greater icon than Sherlock Holmes. We often marvel at his ability to solve "impossible" crimes, but we forget that deduction is a muscle that requires constant training.

 "The world is full of obvious things which nobody by any chance ever observes." — Sherlock Holmes. Solving a Sudoku is the ultimate act of deduction. Like the great detective of Baker Street, you must look at the evidence (the numbers provided) and eliminate the impossible until only the truth remains.