When do parents cross the line between healthy encouragement to prepare their children for success and pushing them to succeed at all costs?

When they push their child past a threshold where it starts to have a negative affect on their mental state, and can put them in to a slump or depression. it can also cause obsessive tendencies. 

When it is constantly going on and there kids are

They would start pushing them when they would know how much they can take the pressure and some people work great under pressure and usually they would start crossing the when they turn 15 i hope this helps and if u have any more questions just comment below :)

Parents crossing the line between healthy encouragement to prepare their children for succes and pushing them to succeed at all cost, is a statement that proves that parents only want wants good for their kids. Parents do things and sacrifice other things in order for their children to grow and become succesful.

Parents getting involved in the sports life of their children can be a huge boast for the kids. Especially, if the parents have been in the same sports. But it often happens that parents try to see their children achieve what they could not achieve. In the process, they tend to push the limits of their children’s in a way that they themselves didn’t. whereas every human is different. What the kids can do better may be the parents could not. And what could the parents do well, be the children’s do not excel that much at it. There needs to be a carefully drawn line between pushing too hard and being supporting.

I think they cross the line when they force sports into their child's life, and take away their choice of what they want to do so they essentially waste their childhood preparing for something that may never happen or they just don't get the opportunity to explore their artistic abilities.

Explanation:

Sports is a good thing for some children because of self-esteem issues. Confidence can also be built for the children and this is important for the future. By participating in sports, children learn to set goals. However, healthy encouragement is a great thing for kids, but only if the children want to continue playing. If the parents are doing this for their own benefit because they played sports or they wanted to play at that age, the line has been crossed.

Well one is they are supporting the child in his/her choices in the field of what they chose and doing what is in their power to help said child.

The other is making them try to be number one and doesn't care about what they really want to do(usually) and try to do what's in their power to make them win. Usually the feeling comes when the parent/s has something in their past that they didn't succeed so they force their child to live the life they had as kids, but to give them what they got to win in life or in that area.