Every free-agent class has its different strengths and weaknesses, and this winter brings a very strong group of starting pitchers. At the top of the heap, there are aces in Gerrit Cole and Stephen Strasburg, followed by a strong group of mid-rotation starters that includes Hyun-Jin Ryu, Madison Bumgarner, Zack Wheeler, Dallas Keuchel, Rick Porcello, Cole Hamels, Michael Pineda and Tanner Roark. The trade market might add a few more potential targets including Matthew Boyd, Robbie Ray and Marco Gonzales.