After we moved yet again. We got our kids in a local youth league at the start of the season. Due to my kids being many lanes apart I really never watched many of the older kids bowling. The past few weeks I have started to really watch them. My son usually has a little knee bend but has not due to being fast lately. I see one other kid that has a slight knee bend. All the other kids in the league are stiff legged when they throw the ball. I asked the coach about it and got a response of they are stuck in their way. Now I was asked to help coach even though I am not a certified coach, there are ok with that. But I have just watched instead of helping out due to being new the area. Here are my questions, what is the best way to go about trying to change this? Also since the current coach thinks the kids are stuck in their way is there any chance this will work to start working on the kids to have a knee bend? Right now they all throw the ball into the lane and not roll it on. They loose so much due to this. Some of these kids could be decent bowlers with a little help. Thoughts?

In working with my son's team, while I will make recommendations on small changes, a lot of what I will see I will discuss with the head coach first to make sure he's in agreement.  This allows for balance to be maintained as (a) I don't want him thinking I want the head coaching job and (b) I want to make sure we both have the same message.

If something is changed and the other coach sees it, he might decide to try and change it back, not knowing that you made the change to begin with. 

Communication is the best place to start, and then you see what happens from there.  Leads to good respect too.

The problem is the way most junior leagues are conducted.  The bowling centers have the kids come in to bowl their 3 games for score and have coaches walk around the concourse and expect the kids to listen to them while they are bowling league.  If they would set it up differently so that there was time for instruction before or after the leagues session the kids may listen.

If a coach is set their way, there is probably nothing you can do to change them. I suggest that you get the Level 1 certification and get involved (It can be done online and its cost very little money).

Thank you all for the advice. As far as communication with the coach I did talk to them already. I know the time frame depends on each person but how long does it take to do the class? With myself trying to do my schooling and focusing on that I don't want to take away from that.
The center I used to work at had one coach and he would turn lanes on after league but there were so many kids that went down there it became a time to mess around more than a coaching session. That is my experience with it and part of why I am not fond of it. But yes I do like that idea for working on some major items. I do like having a coach there during to help with little things.