Your actual reported data. The color shows where you are with respect to your yellow brick road:
good side of the road
off the road
Yellow brick road ?
Keep your dots on the road!
Akrasia horizon ?
This line is a week away from now. You can only make changes in the steepness of your road beyond the akrasia horizon.
Yellow guide lines ?
These thin yellow lines indicate the good side of the yellow brick road. The thicker line demarcates 7 days of safety buffer. (If you keep your safety buffer at 7 days or higher then you're immune to being stung. If anything comes up, just flatten your yellow brick road. It will take effect after the 7-day akrasia horizon but since you have that much safety buffer, you're golden!)
Optimistic projection ?
An optimistic view of progress, i.e., a view of your data through rose-colored glasses. It shows your inexorable march towards your goal. If you're bouncing around it just shows you flat. When you go down (or whichever direction your goal is), it shows you that right away.
It never shows you going up (or whatever the wrong direction is) unless it's sure you've screwed up.
If you find the random fluctuation unnerving, you can focus on the pink dots day-to-day.
Moving average ?
This is an exponentially weighted moving average with smoothing constant 0.25. It shows the overall trend of your data, but lagged. If most of your daily numbers are below this trend line then you are inexorably dragging it down.
For the case of weight loss, this is another way — proposed in The Hacker's Diet — to see the forest through the trees, to see past the daily random fluctuations to what your weight is really doing.
Polynomial fit trend ?
Think of this as a very thick line charting your progress or an aura around your actual data. (Technically it's a polynomial fit of your data.) It gives you a sense of your true trend.
Features not enabled on this graph:
This goal has the following fine print specified by howtodowtle:
Cards added to one of my Anki decks. This is mainly to keep myself adding cards. Four per month is ridiculously low (I think), but it's much better than none. And hey, that means, I will have remembered 503.85 new things by May 8, 2029 (says Beeminder)! :)