MLB may stand for several different things. It is most commonly understood to stand for "Major League Baseball", a baseball organization popular in the United States. In business and accounting it stands for "Material, Labor, Burden."
Major League Baseball Players Association
Performance enhancing drugs
Yep, Major League Baseball or MLB.
No. Major League Baseball is real.
Major Baseball League
Yes. Major League Baseball is the name of an organization and is therefore a proper noun. Iterations such as "major leagues" don't need to be capitalized, because they are not proper.
major league baseball is the hightest baseball league with the best players
Major League Baseball.
Major league baseball is hardball.
Major League Baseball. It was founded in the late 1800's
Bud Selig is the Commissioner of Major League Baseball.