Many teams will show little if no Improvement from Jan - Apr. A lot of these team don't even start practice up until Feb 1. I would hope and expect most will show improvement from March 1 thru August. In the case of Mr Blue some will expect to improve DRASTICALLY.
Blue this is not meant as a slam towards you but I do think it's funny when coaches claim the improvement is all because of them as a coach. I personally do not feel coaches have enough time each week with these players.
The level of athlete and commitment of the family you are dealing with has a lot to do with how teams improve. I am a believer you can not make Chicken Soup out of Chicken Sh** Athletes have to be committed to working outside of practice and parents have to understand the commitment the are getting into. We were involved with a team a few years ago were the players and parents had little commitment outside of practice. Out of 11 players only 3 did some kind of lessons outside of the team whether it was hitting fielding or pitching. The coach was very good, worked well with the girls and really taught them a lot but there is only so much you can do in the few hours a week you have with them and if they are not working outside you are only going to go so far.
IMO, at this level softball is not a Tuesday, Thursday and every other weekend thing. If you want to do that stay in Rec