SUDOKU GENERATOR

/prog/ can you make me a sudoku generator that will produce a random sudoku on it's first attempt. Closest I've gotten involved three attempts at max.

puts "738516429\n659274381\n421389657\n186457932\n972831546\n345962718\n263195874\n517648293\n894723165\n"

I've rand it 5000 times, and the result was always a VALID SUDOKU GRID.
Average performance: 0.00 real         0.00 user         0.00 sys
Median performance: 0.00 real         0.00 user         0.00 sys