Clayton Blackburn, RHP, San Francisco Giants Current Level: A 2012 Top 15 Prospects Ranking: 12th Current Value: Skyrocketing Blackburn, 19, is having a breakout season in his first full year in the minors. The right-hander has struck out 62 batters in 53.1 while issuing just 10 walks. He’s also induced a high number of ground-ball outs while allowing just one home run. Blackburn has allowed one run in his last three starts (22.1 IP) with 11 hits and two walks allowed. He’s struck out 21.The Texas native has now made 22 appearances over the past two seasons and has yet to truly struggle. Signed to an over-slot contract as a 16th round draft pick in 2011, Blackburn has the ceiling of a No. 2 or 3 starter. The Giants organization just continues to find a way to identify and develop top-shelf pitching prospects.