Sacrifice is part of baseball, the idea of giving yourself up for the benefit of the larger group. We have the sacrifice bunt and the sacrifice fly. We move runners, we take one for the team, we save games, we hold leads created by the work of those who came before us. It's in baseball's DNA, a necessary part of winning in team competition.

Throughout history, we've come across the rare people who alter that DNA, not just through the record books, but by creating real societal change. Three of those players were Jackie Robinson, Roberto Clemente and Wally Yonamine, and over the past 18 months, I've had the pleasure of interviewing their children. On this Father's Day, it seems fitting to consider what they can tell us about their fathers, who in many ways were fathers to our game.

The Yonamine family at the Tamagawa training grounds in 1958. The Yonamine Family at the Tamagawa training grounds in 1958.

"My mother used to say, 'It is the quality of time, not the quantity.'" -- Amy Yonamine, daughter of Koname "Wally" Yonamine

Wally Yonamine was the first Japanese-American to play baseball in Japan post World War II. He also played a year of professional football with the San Francisco 49ers in 1947. He was the first person of Asian ancestry to play in the league (the 49ers were in the All-American Football Conference at the time). But his heritage proved complicated.

Battling the perception that he was a traitor in Japan for being an American with Japanese roots, he was met with harsh treatment. By the end of his career, he had won over a nation as an eight-time All-Star, league MVP, nine-time Japan Series champion, a coach and a mentor. He was also the first American to be enshrined in the Japanese Baseball Hall of Fame. His work was so transformational that the Emperor of Japan recognized him for improving diplomatic relationships with the United States.

He also was a father of two daughters, Amy and Wallis, and a son, Paul.

"His sacrifice," Amy says, "was not being with his family all of the time. We were raised in that environment, so it became normal. But it made me see that my mother sacrificed a lot. She married him at 21 years old, and a week after their wedding, he left for 40 days of spring training."

Once he was an established ballplayer in Japan, primarily with Tokyo's Yomiuri Giants, it became difficult to spend as much time as he would have liked with his family. "I was born in December, so it was in the offseason," Amy said, "but my sister Wallis was born during the season. When my father asked his manager if he could be with my mother for Wallis' birth, he was told 'if you don't come with the team, you will lose your spot.' He had to put my mother in a cab to the hospital.

At times, the kids sought divine assistance to gain family time. "We were the only kids in the neighborhood that would pray for rain. That meant Dad would come home."

The stress and job insecurity of baseball in Japan pushed Yonamine to train harder. Even after numerous All-Star appearances, he practiced on off-days with the minor league team, family in tow. There were no guaranteed contracts.

"Every year when his contract had to be renewed, it was a tense time for the entire family," Amy says. "We knew that if he did not get a contract, we would have to go back to Hawaii, and he had nothing to fall back on."

So the family protected their father out of love and pragmatism.

"One time, my father came home, and the lights went out," Amy says. "He held the stool, and my mom changed the fuse. She did it because if that fuse sparked and burned his fingers, he wouldn't be able to play. But my father was always appreciative of my mother's sacrifice. He always credited her for keeping the family strong."

After his playing career, Yonamine went on to coach and manage in Japan, where he changed the culture by bringing his kids around for the summer, which at first was taboo. Eventually, many coaches followed suit.

"The larger appreciation for my father gave us better understanding as we got older," Amy says. "We realized the impact of his efforts to unite people. He was trying to set a stage for foreign players to play in Japan and felt that pressure to open doors for other people. If he was not successful, doors would not open."

The Yonamine family sponsors a high school baseball tournament in Hawaii, his home state. "He wanted to give back to Hawaii, hoping scouts would see the talent and give these young players an opportunity," Amy says. "My father saw education as the key to having choices, and he gave a lot for us and others to have that choice."

Roberto and Vera Clemente with their three sons at Shea Stadium in 1971. AP Photo/Jack Kanthal

"My father once told us 'I want my kids to suffer.' At first, I was shocked, but as I got older, the more sense it made." -- Roberto Clemente Jr., son of Roberto Clemente

Roberto Clemente rose from the heart of Puerto Rico to challenge the cultural homogeneity in baseball. On the field, he amassed 3,000 hits, was a 15-time All-Star, 12-time Gold Glove Award winner, two-time World Champion, Hall of Famer and MVP. He played knowing he carried his homeland and the dreams of future Latino ballplayers on his back. He also spent countless hours helping others. He died in a plane crash as he was trying to bring aid materials after a natural disaster in Nicaragua.

"Everyone knows the story that I told him 'not to get on the plane,'" Roberto Jr. says. "And after the crash happened, people disappeared. There are people close to me that I never saw again. I lost my grandfather a year later.

"His sacrifice was clear. It was how he died," Roberto Jr. continues. "But along the way, he knew he had to take care of himself, and, at times, he gave up friendships, relationships to do so. He had to give up family time. The travel, the missed school years, but he had a gift, a mission to share."

In 1970, when the Pittsburgh Pirates honored Clemente with his own night, it crystallized, for Roberto Jr., how much his father gave up to help people.

"It could be summed up in the first time I saw my father cry. It was late in his career, and the Pirates had Roberto Clemente Night at Three Rivers Stadium," Roberto Jr. says. "He was in the dugout, and his father had flown in to Pittsburgh. Family and Puerto Rico was there in full force. He told them that he was sorry, all his sacrifices he needed to accomplish his mission. He was representing a country, working-class people, hard workers, but he knew he lost something personally in return."

Yet it was the world in mourning that presented a difficult challenge for Roberto Jr. "I was consoling people," he says. He carried a burden in sharing his father with the masses. But he found the strength to focus on the next generation.

"People, to this day, see me as an extension of his legacy, and there are times when people are just reduced to tears. He touched that many people. It is unbelievable. They may know nothing about baseball, but they know his work.

"In the end, it is up to us as parents, as fathers to instill values to make sure our kids understand the legacy of our family. My father passed away at 38 years old, and his legacy feels alive."

Jackie Robinson's wife and children celebrate the Brooklyn Dodgers infielder's 35th birthday. AP Photo

"How do I live up to the legacy?" -- Sharon Robinson, daughter of Jackie Robinson

Jackie Robinson was fighting for better circumstances for people before the Civil Rights Movement was even recognized. He served by being the conduit of racial integration of Major League Baseball. He not only walked the walk on the field with National League rookie of the year honors, a World Series championship, numerous All-Star appearances and an MVP award, but in his post-career, he continued working toward equality for all. He invested in community, started a bank, supported affordable housing, openly challenged and endorsed candidates who he believed had the right platform for racial equality. All of these efforts required focus to stay the course, but to a family, it was more than that. It required time itself.

"You respect a commitment to others," Sharon says. "As the child, when your father is making that commitment, you must share him, and at times, you find that what is going on in your life on a daily basis is not as important as what is happening on a larger scale."

While Robinson was integrating baseball, all other institutions in America were still segregated. His children became pioneers of integration as well.

"When my father integrated baseball, our parents really did not discuss it with us. But simultaneously, we were living in an all-white neighborhood," Sharon says. "It was confusing at times. I felt this pulling away from my world, yet not sure where I should be.

"What people do not always realize is that we integrated our school system in Stamford, Connecticut. We, as in, my brothers and I. No one took time out to really think about what that was like. We were looking at what was happening in the South with dogs sent on people and water hoses, so I found that I internalized my individual pain to focus on the larger pain."

As Robinson marched on after his career in baseball, a sense of "normalcy" returned at home.

"We gained a privacy that we did not even know we craved," Sharon says.

Yet in the fight for these causes, a key decision was made once the kids were old enough to truly participate.

"He brought us into our family mission," Sharon says. "It made us feel like we were now a part of it. We all had a role to play in the larger picture. It gave us direction and focus. We were now responsible for our future."

Their first mission was the March on Washington, then jazz concert fundraisers at home for civil rights leaders. Everyone was given an activity to contribute to the cause. "We cleaned rooms for the musicians to stay, sold hot dogs and sodas," Sharon says. "Now being part of this larger group, it became an important part of our lives as children."

As a mother herself, Sharon made sure to hand off the lesson. "I passed this on to my son. He also became mission driven and proud to be part of it, but it did put on additional pressure."

Coming to terms with the pressure became her "adult challenge," a tug of war. "The search of this true self while applying it to life so you can play a part in other lives. The challenge is that not all of us will live long enough to gain the self-esteem and self-awareness it takes to balance it all."

Sharon decided to step away and pursue her own path. She became a nurse midwife, raised her son and gave herself time to be herself. "Then when I re-entered baseball, I released my privacy by choice," Sharon says, "but I had something to add to the mission."

That mission has been focusing on the next generation through her work with the Jackie Robinson Foundation.

"My parents always kept family as the top priority," Sharon says. "I had my own father-daughter day with dad, and it was important for the time in my childhood but equally important as I reflect back as an adult."