Polo and field hockey are probably out of the question since both require participants to play right-handed, but many of other sports actually allow significant advantages for lefties. Left-handed fencers routinely win medals in top competitions. Left-handed boxers pose serious problems for their opponents. And playing tennis left-handed has not hampered the careers of superstars like John McEnroe, Martina Navratilova or Rafael Nadal.
In baseball, left-handed pitchers have been highly sought after since the sport's earliest days. Since most pitchers are right-handed, batters tend to have trouble clearly seeing a ball thrown by a lefty. The advantage for left-handed pitchers is even more pronounced against left-handed batters. In the 1980s, baseball managers began capitalizing on that dominance by relying on the "left-handed specialist"—a left-handed pitcher who comes into the game to face just one left-handed batter in late innings. The left-handed specialist's average workday could consist of as throwing as few as a five or six pitches—and then hitting the shower before breaking a sweat.
One of the greatest left-handed specialists in baseball history was Jesse Orosco, who played for nine teams in 24 seasons. When he retired in 2003 at age 46, Orosco had set the record for most ever games played by a pitcher at 1,252. He also earned around $1 million a year starting in 1988—not bad for a few minutes of work a day.