Eri Yoshida is a 31-year-old Japanese knuckleball pitcher with a sidearm delivery that she hopes might carry her to the big leagues in the United States or Japan. She says “I know it’s a really difficult challenge, but I have a dream in my heart that I really want to stand on a mound in the majors with a knuckleball.” Even Yoshida acknowledges that it’s a far-fetched fantasy. But it’s also very real. She travels this week to play for two months in the Empire League, an independent baseball league in upstate New York. Yoshida has pitched in games in Japan, the United States, and Canada — against men and women.