Update! The talented Vicky Teinaki made a graphic of this metric and let me use it! She is awesome!
Side 1: Knowledge, or Know What You're Writing Before You Write It
Side 2: Time
Side 3: Enthusiasm
I'd actually broken it before. Using Knowledge and Time, I'd already managed a few 10k+ days, including one where I wrote 12,689 words, or two chapters, in 7 hours. To be fair, I had been writing outside of my usual writing window in addition to my normal writing on those days, so it wasn't a total words-per-hour efficiency jump. But that's the great thing about going this fast, the novel starts to eat you and you find yourself writing any time you can just for the pure joy of it. Even better, on the days where I broke 10k, I was also pulling fantastic words-per-hour numbers, 1600 - 2000 words per hour as opposed to my usual 1500. It was clear these days were special, but I didn't know how. I did know that I wanted those days to become the norm rather than the exception, so I went back to my records (which I now kept meticulously) to find out what made the 10k days different.
Fortunately, the solution turned out to be, yet again, stupidly simple. Every day, while I was writing out my little description of what I was going to write for the knowledge component of the triangle, I would play the scene through in my mind and try to get excited about it. I'd look for all the cool little hooks, the parts that interested me most, and focus on those since they were obviously what made the scene cool. If I couldn't find anything to get excited over, then I would change the scene, or get rid of it entirely. I decided then and there that, no matter how useful a scene might be for my plot, boring scenes had no place in my novels.
Life On 10k A Day
Again, I really hope this helps you hit your goals. Good luck with your writing!
And if you want to read more of my free writing posts, check these out:
12 Days of Glory (or how I wrote a novel in 12 days, complete with daily numbers!), How I Plot A Novel in 5 Steps, and Editing for People Who Hate Editing! I add new writing posts all the time, so feel free to follow me on Twitter, Facebook, or on my RSS Feed (available on the sidebar to the left) for updates and information.
Thanks as always for reading and spreading the word!