For the purposes of this problem, we define an English word as a word from the list included here as words.txt. (If you're interested, it's the SCOWL “insane” dictionary with flattened diacritics.) Membership in the dictionary is case-insensitive. You have to write a program that can answer whether a given word is English. This would be easy — you'd just need to look the word up in the dictionary — but there is an important restriction: your program must not be larger than 64 KiB. We don't think it's possible to write a program that fits in 64 KiB and always gives correct answers. But we don't require 100% correctness. For every program we will measure how often it answers correctly, and the most precise solution shall win.
I decided to spend some time to stretch my mind. Unfortunately, I wasn't on vacation, so the amount of time available was pretty limited. But it was fun, even though there's plenty of people beat my result. I found some weak areas in my approach to problem-solving. Here's what I did good and bad.