>>16
62 → 10 is reduction to a fourth now?
Even if you were to use a case-sensitive captcha, which is beyond the literary capacity of approximately half of all internet users, it still would not be exactly 62 due to the various lookalikes, an example of which have already been given.
If you can print the text to be scanned yourself, OCR can be very close to 100% successful regardless of the size of the domain.
A situation almost directly opposed to the one in actual discussion, the captcha, where the text is specifically meant to be resistant to machine vision techniques. If you are getting next to no classification errors on a modern captcha, the implementor probably went to the same special school that you did.
garbage
Oh dear.