Skill Progression in CDDA

[RickySandbox]

mlangsdorf wrote:

skill increase per task varies with skill and task, but a common formula is you get task difficulty points of exercise every ten minutes if the task difficulty * 1.25 is greater than your current skill. That exercise is adjusted by your current effective focus. You need to accumulate 100 times the square of the next skill level of exercise to increase a skill.

So:
exercise = task difficulty * task length in minutes / 10 minutes * focus / 100
if task_difficulty * 1.25 < current skill, then exercise = 0
if exercise > (current skill + 1)^2 * 100, current skill += 1

For my two examples:
Survivor with Unarmed 3 gains bash damage / total damage * random number between min and max damage of practice every time he hits a zombie. He's doing between 0 and 10 damage per strike, all of it bash damage, and the zombie has 80 HP, so I think he should earn about 80 experience for the fight (before adjusting for focus, and each of those 16 punches and 16+ dodges drains focus). He needs 1600 experience to reach Unarmed 4, so he needs to kill 19 more zombies at focus 100.

Survivor with Mechanics 3 does a skill 3 mechanics task for an hour. Consulting the helpful table in veh_utils.cpp, we see he earns 60 practice before focus adjustment. He needs 1600 experience to reach Mechanics 4.

Relevant code references: src/player.cpp for player::practice(), src/skill.cpp for SkillLevel::train(), src/veh_interact.cpp, src/veh_utils.cpp for repair_part() and calc_xp_gain(), src/melee.cpp for melee_train().

What should we be doing differently?