I already wrote about words count challenge. And couple weeks later I found another one about words. You can read detailed description, but the quote below is enough in most cases.
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.