I take a certain amount of pride in my knowledge of proper word usage. I’ve been a word nerd since I was three. But I have never ever ever in my life been able to figure out whether it’s “wracking my brain” or “racking my brain.” The internet was no help; it told me both ways. I tried a dictionary, but it didn’t help either. I could see either word working based on the definitions I found.
So I was flipping through my Chicago today, looking for fun editing tidbits. (Yeah. You thought I was joking when I said I was a nerd.) I started reading through the Glossary of Problematic Words and Phrases (5.220 in the sixteenth edition), and lo and behold:
wrack; rack. To wrack is to severely or completely destroy {a storm-wracked ship}. (Wrack is also a noun denoting wreckage the storm’s wrack}.) To rack is to torture by means of stretching with an instrument {rack the prisoner until he confesses} or to stretch beyond capacity {to rack one’s brain}.
I don’t know how I never saw this in my hours of poring over Chicago, but there you have it. Now I’m headed back to RACK my brain over that clump of 70,000 words that I call a manuscript.
BumblesBooks 
Another one bites the dust. Doesn’t that feel good? I wish more writers were as proactive as you are with this form of personal and professional improvement.
Thanks! It’s always nice to knock another question off my endless list. 🙂
Hmm. I always thought it was wrack, and the definition given is exactly the concept I have always had, that of destroying something – such as your brain – in order to get what you need out of it. To me merely “racking” one’s brain in order to get something out of it is far too mild a description. But then, I suppose my brain is probably more tightly wound than others (I studiously avoided using the word “closed”), and who am I to argue with Chicago?
Maybe that’s where I got my preference toward “wrack” from. I’m glad you’re bending your tightly-wound (certainly not closed, or even narrow) brain to the will of Chicago. It’s a pretty mind-bending stack of paper.
Yeesh, this is dangerous. You start commenting on my blog, and I go all punny. 🙂