My DD was a lefty catcher/firstbasemen. Start with a catcher's mitt early, I say, good to get them in habit of catching with it correctly -- one handed and framing properly. Why not start early? : > For a first basemen mitt, she got one before she started her freshman year in high school and first year of serious "A" ball. It was the right time and made a huge difference for her. She went through two catchers' and two first basemen mitts in four years, probably because we never popped for a multiple hundred dollar glove..but the math probably ended up being mostly the same.