Realistically, max distance is not achievable with each jump. Running long jumpers often have multiple feet of difference between their various jumps. If I wanted to introduce randomness into jumping, I'd probably allow up to 2/3 distance to be achieved automatically. If you want to go farther than that, you roll a D20 and add your athletics bonus and that's how far you would go to a maximum of your strength and a minimum of 2/3. Special circumstances such as bounding off of a rock or pulling yourself farther on a stalactite and the like would be required to go farther than strength distance, in order to keep it unusual.