Good Egg or Bad Egg?

How do you tell a good egg from a bad egg? I used this test when we had rebel chickens who used to lay in the oddest places & I didn't know how old the eggs were.

Here's the test...Fill a bowl with cold water. Drop the egg, gently, into the water.

fresh eggs........lie on the bottom
1 week old eggs...lie on the bottom and bob slightly
3 week old eggs...balance on the bottom on the small end
older eggs........barely float off the bottom
BAD EGGS..........float to the top of the water

Note: The fresher the egg, the more the yolk "stands up" when fried. Also, the fresher the egg, the harder it is to peel after boiling.