Torii Hunter was in for a surprise. Two days before Christmas 2005, his father gathered him and his three brothers together to tell them they had a half brother.  Theotis Hunter pulled out a high-school prom picture of Brandon Thurman, then 17, and told them that a DNA test had just confirmed his paternity. Adding to the shock: Their newly discovered sibling would be joining them for Christmas dinner at Torii's Dallas home. "I felt like I was in a soap opera," Mr. Hunter recalls. "He looked just like my dad. Six-four. Had the same face. It was amazing."  Recently, the blended family celebrated another major achievement: the graduation of Brandon Thurman from the U.S. Military Academy at West Point.  If there's ever been a near-perfect illustration of how natural-born talent can emerge even from the toughest of circumstances, it's the story of these two brothers—a superstar outfielder for the Los Angeles Angels and a young U.S. Army officer bound for a war zone.  The brothers, who have never talked publicly about their reunion, both grew up in Pine Bluff, Ark., a town about 45 miles outside of Little Rock with one of the highest crime rates of any metropolitan city in the U.S. Mr. Hunter admits to carrying a gun around Pine Bluff for safety as a youngster. He also remembers often playing cards by candlelight with his brothers because his father, then a crack addict who often squandered his paychecks on drug binges, left the family unable to pay its electric bill.  Mr. Hunter and Mr. Thurman both graduated from high school, but many of their peers did not. The state's high-school graduation rate for black males is 61%, but only 29% of black students who start high school in Pine Bluff are considered college-ready when they leave, according to Marcus Winters, senior fellow at the Manhattan Institute for Policy Research.  Torii Hunter of the Angels.  Mr. Thurman's mother, Gloria Hampton, a nurse who recently retired after 20 years and also served in the National Guard, opted to not reveal who Mr. Thurman's father was, saying she didn't want to stir up too much small-town gossip in Pine Bluff. She and Theotis Hunter didn't see each other for years, so Mr. Hunter didn't know about Brandon. Meanwhile, Brandon struggled with not knowing his biological father.  "He was always bitter," Ms. Hampton says. "You know, children are bitter when they have a father that's not around them." In raising him, she kept him focused on academics, athletics and the Junior Reserve Officer Training Corps program, always with the goal of keeping him active and away from trouble. "The child was seeing people do drugs, going to jail, and down the street selling drugs. I would tell him not to get involved with that," she says.  Mr. Thurman set his sights on West Point during his freshman year in high school, inspired by a speech by a West Point grad who attended his same high school, and by Col. Stan Warrick—his JROTC adviser who also graduated from West Point.  "I wanted to get away from Pine Bluff," he says.  He credits his mother for pushing him. "Even when things are bad, she just keeps her head up, she keeps going. And I think that's how we got through difficult times when we were younger, too," he says.  Torii Hunter’s father attends the West Point graduation of son Brandon Thurman, shown with his mother.  Before he graduated from high school, Mr. Thurman's mother decided to resolve lingering questions about the boy's father. "I took him to court" seeking a paternity test, Ms. Hampton says. "I didn't get anything out of it [monetarily], but I got a lot out of it, because Brandon was able to meet his father," Ms. Hampton says.  Torii Hunter has a strong mother, too. Shirley Hunter, an elementary-school teacher, basically supported the family during tough times, all the while scrambling to attend each of her four sons' Little League games. Torii's success changed everything. Mr. Hunter started to use his earnings with the Minnesota Twins (he left the Twins as a free agent and signed with Los Angeles in 2008 and now earns $18 million a year) to catapult himself and his family into a new financial universe.  Some of that money went to helping his father get treatment. Now clean, Theotis has spent the past few years trying to correct his past mistakes, saying his relationship with his new-found son and his other children and grandchildren have helped keep him straight.  "It's an ongoing process. You have to manage yourself every day. You have to kind of watch who you deal with and everything. My grandkids and my family, they're No. 1. They keep me out of trouble," he says.  Looking back, Torii Hunter is impressed that his brother chose to attend West Point even after the war in Iraq had begun. Mr. Thurman says he heard similar sentiments elsewhere. "Some of my friends told me, 'You shouldn't go into the Army. You could get killed,' " he remembers. "But people get killed over here, too. I figured, 'When it's my time, it's my time. I'd rather go out serving my country."  Mr. Thurman is currently training at Ft. Sill in Lawton, Okla., and will be stationed at Ft. Lewis in Washington. He recently learned that he will likely be deployed to Afghanistan or Iraq next year as part of his five-year commitment to the military.  Mr. Thurman was less aware of his brother's talent. He knew Mr. Hunter was a major leaguer, but didn't realize the caliber of player he was. Toward the end of his freshman year at West Point, however, he found out. Some buddies were looking at a photo of Mr. Hunter in Sports Illustrated in their dorm.  "I think it was when he knocked some guy out while he was sliding into home plate," he recalls. "They said, 'Torii Hunter,' and I said, 'Hey, that's my brother.' And they were, like, 'No way, that's not your brother! He's like one of the greatest center fielders ever!' And I was, like, 'Really?' "  As for Mr. Thurman, the discovery of Theotis and Torii has helped answer questions that lingering in his mind. Mr. Thurman always stood out in cross-country, track and basketball, but he never knew where his athletic ability came from. He was plagued by injuries for most of his career as a walk-on sprinter at West Point, but the Hunter genes surfaced during one of his final races, and he set a school record in the 500 meters.  Theotis, himself a star high-school football player in Arkansas in the 1960s, wasn't surprised. Known as "Iron Man," Theotis played both offense and defense, rarely coming off the field. But his dream ended with high school. "I had 17 football scholarship offers, but Vietnam was going on, and I got drafted," he says.  He marvels at how two kids growing up on the streets of Pine Bluff could be so extraordinary. "The odds are probably a million to one," he says.  Right now, the family is focused on strengthening its ties. Shirley and Theotis Hunter divorced, but family members say they remain friends. Theotis flew to New York for Mr. Thurman's West Point graduation ceremony, and Mr. Thurman visited California this summer to see his brother Torii and attend some Angels games. After the military, the future is less clear.  "I will need to stay in the Army until 2014, but I don't know if I'll stay or leave after that. If I decide to get out, I'll do law," he said. "I've thought about sportscasting. I think that would be a nice job, too, and Torii has a lot of contacts in that area."  Meeting Mr. Thurman and seeing all of his sons excel in life has helped soften Theotis's past personal disappointments. "It was a load off of my chest," he said of finding out about Brandon. "I didn't want to go through life not knowing he was my son. That was something that had to be resolved, so I took the test, and it came out 99%. So it's all good."  Write to Lee Hawkins at lee.hawkins@wsj.com
How Torii Hunter, the Los Angeles Angels' star outfielder, overcame hardship to succeed in the major leagues. Then he discovers that a long-unknown half brother surmounted equally impossible odds.