Deck repair questions

Introduction

I felt the desk surface getting more flexible than I wanted so I investigated. This series of web pages shows images of what I see, and at the bottom of this page is a short video.

View 1

These photographs give a sense of what I’m seeing. The North (Left as facing back of home) side isn’t as bad…

View 2

…as the Right side. Please look at the video below, then come back up here and click “Next Page” button.