Chelsea Baker is a high school pitcher who was taught to throw a knuckleball by former big league pitcher Joe Niekro.
She first hit the national radar in 2010 as a little leaguer. Four years later, she is throwing batting practice against the Tampa Bay Rays.
Here is a special segment shown on ESPN about her day. During the video, she does hit Evan Longoria with one pitch (he later had some very kind words about her performance). But she also makes several players look silly with the knuckleball, including David Price.