Coach Mommy and Daddy
There are two types of parent coaches. You could be the coach who draws the line between coach and parenting and treats your child like every other player or you could be the coach that favors their child and only wants whats best for them.
The first type of parent coach knows how to handle the situation and doesn't favor their child. They treat their child like everyone else on the field. They actually know the tactics of the sport. This creates the least amount of favoritism on the team. But when talking about favoritism you cant be overly hard on your child to eliminate it because that will just create a horrible experience for your kid. They may feel pressure to be better with their mom or dad coaching them.This situation also creates conflicts between the parent child relationship. The child could be frustrated with your coaching tactics and avoid all conversation after any practice or game. Also tension could be created at home because the child may get the wrong idea and expect special treatment since it's either her mom or dad as a coach. The type of parent coach really draws the line between parent and coach and knows the difference of being a coach on the field and a parents at home making it the best experience for the child.
The other type of parent coach is the one that wants to get involved and wants to create the best experience for their child. This could create a great relationship between parent and child but kind of eliminate the team chemistry that is essential. In this situation the parent doesn't know how to draw boundaries between being a parent and being a coach. The parent them self may not even take into account the sports tactics or anything they just want to be involved with their child. The parents wants whats best or their kid so they favorite them and may give them the starting position or more playing time not taking talent into account. This could improve the parent and child relationship because the child is getting that special treatment but creates an unfair advantage to them. The other kids may be better but aren't getting the playing time they deserve due to the favoritism. Also the kids may feel uncomfortable talking about the team or give an opinion since the coaches child is on the team. This type may create a good experience for their child but doesn't create a good team or fair opportunities.
I personally believe that parents shouldn't be their child's coach. I know it's fun and all but it eliminates all the things that could happen. I think the parents should be the kid's biggest fans if anything and be there to support them from the sideline not the bench.