Soggy Middles and Tension Headaches

The middle of a manuscript may be the hardest part to write. If writing yours is giving you a tension headache, here are some ideas.
Like an overly-laden peanut butter sandwich, manuscript middles can get soggy. To keep the reader interested, however, we have to fix this peanut butter jam (sorry) because manuscripts, unlike people, thrive on tension.
I recently analyzed a book with the intent to improve my own plotting. About a third of the way through, my interest slowed. So I outlined the middle chapters, rating the escalation of tension for each.
Events still happened in the story, but the plot seemed to move around instead of up. An article in the January 2011 Writer’s Digest helped me identify why. “The story needs to progress toward more and more conflict, with…deeper tension…Because of that, repetition is the enemy of escalation.” 3 Secrets to Great Storytelling, Steven James, Writers Digest, January 2011, p. 41.
The book had several chapters in which the main characters did almost the same thing, and the antagonist responded in almost exactly the same way. The repeating pattern explains the going-in-circles feeling. But some repetition is necessary, right? We’re familiar with the rule of threes, originally based in comedy. Fiction writers use it as well. As an example, a plot may require a MC to make three attempts before s/he accomplishes a particular goal. So what’s the difference between a useful rule of three and repetitions that bore the reader?
In the WD article, Steven James points out, “Every murder you include decreases the impact that each subsequent murder will have on the reader. Every explosion, prayer, conversion...means less and less to the readers, simply because repetition, by its very nature, serves to work against the escalation your story so desperately needs.” He urges writers to “Strive, instead, to continually make things worse for the protagonist.”
A while back, I did some editing on an old manuscript. In it, the MC experiences verbal abuse. Knowing that abuse typically goes in cycles, I tried to follow that pattern in my book. Now, however, I know I need to go back and make sure these cycles aren’t acting like so much extra sandwich filling.

I’ve come up with some questions to ask myself:
1. Does each chapter have an important purpose that moves the plot forward?
2. When I use repetition, is there a legitimate purpose and necessity for these repeated events?
3. Does each repetition escalate, the plot tension? Or does it detract from it?

Escalating tension can be one remedy for the headache of soggy manuscript middles. And once you've fixed your manuscript, make sure to enter it in the WIFYR's $1000 contest. www.wifyr.com (see my last post.)