His ability to strike out batters is due to frame and his pitch selection. Brown is a 6'6'' right-handed batter who, once again according to his 2008 Bowman Card (which is always a great, fast introduction to any prospect), keeps his pitches down, uses his slider as his out pitch and gets good movement on his fastball.
So far in the minors, his strikeouts per nine innings have stayed constant except for this year and last year. In 2005, his K/9 was 8.21, with his stay with Brooklyn in 06, it dropped to 7.07 and then in 06, when he moved to Hagerstown, it increased to 7.32. Last season though, it dropped like a rock to 4.26 and right now its back on a slight rise to 4.64.
His ERA has fluctuated over his time in the minors with the Mets. In his first season he pitched 34.0 innings with an ERA of 3.97. His first 70.0 innings in 2006 (Brooklyn), were awesome as he posted a 1.16 ERA. (He was honored with an All Star Appearance for the New York Penn League in 2006 due to his dominance.)The next half of the season was not as awesome as he posted a 5.16 ERA over 62.2 innings in Hagerstown. He pitched the most innings in 2007 (143.2, roughly 10 more than 06) and posted a good ERA of 4.13. This season he has been struggling over 42 innings with a 6.33 ERA. (This season he is pitching in AA, and facing tougher batters).
Between his ability to strike out batters between the minors and college, and his good ERA for most of his career, he could make an impact in the majors. He should be interesting to follow and lets see how he finishes out his 2008 campaign. Lets see if he can drop that ERA.
Image of his 2008 Bowman card from Ebay.

