David Hernandez was drafted by the Orioles in the 16th round of the 2005 draft, out of Cosumnes River Community College in California. Not a big guy at 6-2, 180, he nevertheless impressed scouts with his athleticism and projectable 89-92 MPH fastball. He posted a 3.89 ERA with a 47/17 K/BB in 41 innings for Aberdeen in the New York-Penn League in '05, I gave him a Grade C in the '06 book, pointing out the strong K/IP ratio but noting there were a lot of short-season pitchers like him out there...some would succeed, many would fail. Which group would Hernandez fall into?
Moved up to Delmarva in the Sally League in '06, Hernandez went 7-8, 4.15 with a 154/71 K/BB in 145 innings, 134 hits allowed. Again, his K/IP ratio stood out as a big positive, though his walk rate was high and was the main thing holding him back. He was still throwing 89-92, but his slider was starting to draw notice as a potential plus pitch. I gave him another Grade C in the '07 book, but wrote that if the walk rate started to come down, he had breakthrough potential.
Hernandez did lower his walk rate in '07; he posted a 168/47 K/BB in 145 innings for Class A Frederick, allowing 139 hits. HIs K/BB, K/IP, and H/IP marks were all better than league average, and his WHIP dropped from 1.41 to 1.28. He continued to improve the slider, and his sustainable velocity increased into the 91-93 range. Yet despite the component improvements, his ERA went up to 4.98, thanks to a higher home run rate and worse performance with runners in scoring position. Although I gave him another Grade C this year, I wrote that he was a better prospect than the ERA indicated, and that he was a candidate for a breakthrough....this is a good example of why you have to read the comments in the Baseball Prospect Book rather than just look at the letter grades.
Double-A is going well. He is 5-1, 2.83 with an 87/38 K/BB in 76.1 innings for Bowie in the Eastern League, with an 87/38 K/BB and 61 hits allowed....excellent K/IP, low hit rate. HIs walk rate has risen again, back to 2006 levels, but the ERA is down thanks to fewer hits...granted much of that can do with defense and luck of course. Splits are interesting....righthanders are hitting .215 against him and lefties .224, not a major difference, though lefties have a higher SLG against him. Home/road splits are 2.48 with 36/19 K/BB in 40 innings at home, 3.22 ERA with 51/19 K/BB in 36 innings on the road...interesting that the strikeout rate is signficantly higher on the road, though as with Neftali Perez I don't know if it means anything given the sample size. He's posted a 1.93 ERA in June, but with a 18/10 K/BB in 19 innings. He is a fly ball pitcher with a 0.60 GO/AO, and has given up 7 homers this year, on pace for 14 or so in a full season, in line with his career norms.
Although the improved ERA makes it look like Hernandez is having a big breakthrough campaign, and I love the strikeout rate, the slippage in his control is an issue and perhaps this is just the flip side of 2007....some bad luck inflated his ERA last year and maybe good luck is deflating it a bit this year. Nevertheless, I do like Hernandez and I think he's a very good prospect, probably a Grade B.