What do I want out of a "to hit" table?
- all classes start out the same as far as combat effectiveness;
- fighters progress faster than clerics/magic users, but not too fast, and never become unstoppable;
- the progression is easy to grasp and can be quickly calculated in your head, if necessary.
The Target 20 algorithm helps to meet point 3, as long as the combat adjustments for monsters and classes are regularized. What I'm thinking is: use the original d6 hit dice progressions for the classes and monsters, and make the "to hit" adjustment equal to the hit dice. Monsters with hit dice plus adds round up to the next hit die, characters don't. However, this does make fighters progress too rapidly. I may have to tweak the character hit dice, if I go with this.