Having coached two of his children in youth baseball, Timo Donahue knows there's a line between bonding with his sons and berating them as players. But that doesn't mean he has always respected the boundary.

There were moments he wishes he could take back — moments when he was too hard on his 13-year-old son, Christian, a talented hitter who led his Waipi'o teammates to the Little League World Series title this summer.

"There have been times where I wouldn't have done to another kid the things I said to him," said Donahue, who started coaching Christian when he was 4 years old. "If he wasn't my kid, he wouldn't have got what he got in front of the other kids."

Every week, at practices and games, Hawai'i parents like Donahue are challenged by the pressures of modern youth sports. Their participation is vital to leagues short on coaches, but child behavior experts caution they must tread carefully or risk trampling the emotions of the very players they want to shine: their own children.

The parent who coaches his or her own child must keep the big picture in sharp focus, said Sylvia Yuen, director of the Center on the Family at the University of Hawai'i-Manoa.

"I think most parents want their child to be successful in life," she said. "Understand that this is just the road to where you want to go. Don't get caught up in the moment. Allow your child the freedom to gain confidence and fail."

Young children, especially those 8 to 12, are searching for activities in which they can excel — sports, art, music, academics, Yuen said.

"A major task for them is to develop confidence, which goes hand in hand with developing self-esteem," she said.

If parents "overstructure," coaching and guiding every moment of a game, their child will never learn to make independent decisions, Yuen said.

"We need an opportunity to fail in a safe kind of way," she said.

The 41-year-old Donahue, who has also coached baseball at the high school level, said he learned to tone down his verbal deliveries after he started coaching his other son, 7-year-old Jordan.

"It is a shame that I didn't understand it before," he said.

But Donahue, a Honolulu police detective who grew up under the watchful eye of his own father-as-coach, considers himself blessed for the many years of coaching his oldest son. Not all fathers are able to coach their children, he said.

"Not only do I feel that I am giving him quality instruction, but it also lets me spend time with him as well," he said. "Had I not coached him, I would never get that time back again."

Young children, especially fourth- to sixth-graders, present special challenges to the coaching parent, said Dana Davidson, a UH professor specializing in child and adolescent development.

"They are very sensitive to their parents' criticism because they are trying to hard to develop skills and do well," she said.

It's a heavy dose of responsibility.

"Be careful not to compare your own kid to kids who play better or worse," Davidson said. "It's hard, but if you don't do that, then you face a chance of putting so much pressure on kids. They might burn out on the sport rather than developing something they would enjoy their whole life."

Retired Punahou coach Chris McLachlin, whose resume includes teams of 5-year-old soccer players, high school champions and Olympic athletes, said the job takes years to master. It's the reason he thinks parents who coach deserve praise — and as much training as a league can offer.

"It is such a difficult thing to do," the 63-year-old McLachlin said. "It takes a long time to learn how to do it, and we ask these parents, who might have no skills, to go out and coach a team."

McLachlin estimates that he coached more than 2,500 athletes in his 43 years as a coach, including his three children. His oldest, Parker, is a professional golfer.

"I don't think that I pushed too hard," he said. "I probably erred on the side of trying to be more nurturing."

He credits the approach with maintaining Parker's continued love of golf.

"I figured that the last thing you wanted to do was burn him out by pushing him more," he said. "I probably took a bit of a risk. Sometimes parents need to make kids do things the kids don't want to do. But sometimes in athletics it is better to have it be their choice as to when they are going to practice or not play the game."

Push too much and you risk a fractured relationship, McLachlin said.

"The biggest challenge is to make sure that you are being fair so the other kids don't feel there is prejudice or bias," he said. "And at the same time, if your child is deserving of play, you don't want to be so fair that you penalize him. It is walking a fine line. You have to hope that you walk that line carefully and do the best you can."