I think it really depends on the age group you are coaching. I have been coaching baseball for a very long time and I know I faced different challenges coaching a tee-ball team versus teenagers.
The really young kids cannot comprehend all of the details in the game. As long as they are playing some attention to the game and going for the ball that is about all that you can ask. Expecting a five year old to know there is a force out at second is really not very practical.
Coaching older kids can be tough as well because they already know everything and aren’t afraid to tell you so. They can get more engrossed in the details of the game but will vocally voice their displeasure about a called strike three or a missed call on the bases too.
For all age groups the hardest thing, for me, is dealing with the parents. Ever year there is that one parent who wants to tell everyone how great their kid is or is constantly riding their tail about what they are doing wrong in the field. Great job Mom and Dad, make the child feel terrible in front of everyone, great way for them to learn the game and make friends. I have seen more kids quit sports because of their parents then because they just don’t want to play anymore.