Really love this supplement you wrote, it's really amazing. One question though, under the class features that say Combat, what exactly does this mean? An example of my quandary is how the Fighter says it advances attacks and saves by two points each level, but when I look at the chart it doesn't look like the saves are advancing that way. Can you help me understand this a bit better?
Thanks for the comment, MxOberon!
Fighters advance both attacks and saves by two points every three levels of experience, not each level. So, in other words, over the course of going from level 1-4, you can see that fighters go from an attack bonus of +1 to +3 (so an improvement of two points), and their saving throw target goes from 14 to 12 (so an improvement of two points).
It's worth saying, I suppose, that actually trying to figure out what your Combat advancement is with a phrase like "two points every four levels of experience" in the middle of a game is messy. The only reason I wrote it out explicitly is that if people wanted to use this model to build other classes, it would give them good guidelines that are balanced but progress faster than purely going by B/X numbers.
Hope this helps! Feel free to ask me any other questions you might have. :3