Dominic Smith could have become bitter.A first-round pick and top prospect, he entered professional baseball with expectations of stardom. But in recent years, he has bounced between organizations, signing short-term deals and fighting to keep his MLB career alive.Even through all of that uncertainty, the people around him say his approach never wavered. Smith has maintained a good attitude everywhere he’s been, including with the Atlanta Braves. He signed a minor-league deal with the team in spring training without any assurances about what his role might become.He turned the opportunity into a spot on the Opening Day roster. A few months later, Smith has emerged as one of the team’s most valuable spot contributors.“There’s some humbling that goes on there,” said outfielder Mike Yastrzemski, his teammate in San Francisco for a few months last season. “He took that really well, as a new opportunity, and was never asking for anything. He was always in a good mood, trying to figure out what way he could be there for the team.”Among players with at least 100 plate appearances, Smith’s .325 batting average ranks third in MLB. He has been especially effective in clutch situations, hitting 11-for-29 with runners in scoring position. He has also had two games with four RBIs this season.“When we signed him, you’re wondering about where the fit is,” Braves manager Walt Weiss said. “But he has hit his way into the lineup.”