When the Pokemon is caught it increases its level by the amount of health it has left...
The Poke-ball has a 15% chance of catching the Pokemon depending on level...
That's interesting. I like it. An I Idea that I have: Since your pokemon get experience when you catch a pokemon, then your pokemon that you used to catch the other gets more experience when you catch one. Maybe 150%~200% the experience that it would have received when you caught the pokemon.