
I like this chart because I've been thinking of something much more like a bell curve--straight up and down. But this one has little spikes for each of the crises.
I decided to come up with my own chart. For each chapter, I assigned a number 1-10 for tension. But my book's strength, I think, is that it not only has tension, but also a great deal of emotional response from the reader. So I gave a number for emotion, too.
So, here's what I came up with in my own work

Along the bottom is every chapter. Then I gave a numerical rank of 1-10 on tension (red) and another rank for emotion (blue). Basically, for the purposes of this, tension = how on the edge of my seat I am, and emotion was how heart-wrenching the scene was.
Now, you may see immediately that my graph has a lot of up and down spikes--that's because I alternate POV in each chapter, so while one character's tension is rising in his story arc, the other character's maybe isn't. While I think next time I'll separate it based on the characters, I think I can see a clear line here.
Of note:
- A spike of tension at Chapter 3; a spike of emotion at Chapter 5. Those were my early hooks.
- The 20s are low, but the rise is in the 30s and a climax in the 40s--imagine that as a steeper, steadier curve with the overall plot--those are the "crises" that keep the reader reading (I hope)
- The last chapters shoot up in tension--this is the revelation of the murderer--and emotion--the revelation of the "twist"
- In the last chapter, tension shoots back down, but emotion shoots up. I wanted to leave the reader emotional, but with questions asked, so I think that's accomplished here.
Corollary:
- This was MY numbers--what *I* think is heart-wrenching or tension-filled. Another reader may not have that reaction. While I'm happy with how my overall story arc looks like, it's only effective if my readers think that those heart-wrenching scenes deserve a ten, or that tension is worth top points.
So, how do you track your story arc?