Phil Hughes answers readers questions, including how he throws his curve ball:

There are a few different ways to throw a curveball. The most traditional way is to keep your middle and index finger down on the baseball. The way I throw it is to "spike" my index finger on the ball by digging my nail into the seam. This is known as a spike curveball, or knuckle curve. I'll bet there are quite a few guys that throw it this way, Mike Mussina and Ian Kennedy being 2 I know for sure.

I've never heard of this pitch refered to as a spike curveball before.