Well, before you finalize your guess, I'll give you a hint: it's either 2, or 437. It's not any other number.

Keep in mind I made my choice before we started, and it hasn't changed.

Do you want to change your guess to 437, or stick with 2?

I've always flip-flopped on grasping the Monty Hall thing (sometimes I'd think I understand, other times not so much)... but this little guessing game really clarified it for me, once and for all. Thanks!

This is a nice reinterpretation.