A little over 1/4 into the season, let's take a look at how the starting pitching has performed thus far.
RH - Derek Lowe
2-4, 5.34 ERA, 1.51 WHIP, 55.2 IP, 17 BB, 39 K
To say that he's been a huge disappointment wouldn't do justice to how badly he's played. It's the same old BS with him year after year - some great starts, but more awful ones. His number back up my statements quite nicely. Look, I know he can't possibly be this bad of a pitcher, but he has got to step up and be one of the leaders on the staff. His ERA was as low as 2.45 on April 23, and has gone north since then. With the Diamondbacks playing so well, they can't afford one of their top pitchers to be this bad.
RH - Hiroki Kuroda
1-3, 3.67 ERA, 1.33 WHIP, 54 IP, 16 BB, 31 K
For being the 4th starter, I think he's played very well so far. He's not asked to put up ace-like numbers, just anchor the bottom end of the staff, which he has done. He won his debut in San Diego and hasn't been on the winning end since. By my count, there's 6 other games in which the Dodgers could have won if they gave him more run support. Not a big shock there. In his last 2 starts, he's racked up 5 K's each, so he seems like he's getting more comfortable.
RH - Brad Penny
5-4, 5.09 ERA, 1.49 WHIP, 53 IP, 18 BB, 28 K
Ya know all of that stuff I just wrote about Lowe? I could pretty much copy it for Penny. The great 1-2 punch each has ERA's over 5 and have been pounded into the ground lately. He had a good stretch in mid-late April in which he seemed to get his control issues figured out, but his last 2 starts have been atrocious. He doesn't strike out nearly as many guys anymore, which is another reason for concern. And, above everything else, he is battling a sore arm right now. I have a better feeling that he'll turn things around than Lowe, so I'll give him the benefit of the doubt that it will happen.
RH - Chad Billingsley
3-4, 4.34 ERA, 1.49 WHIP, 45.2 IP, 27 BB, 53 K
Bills started off the year very rocky, but has since become a force. After losing 4 straight in April, he's dominated in 3 of his last 4. He's capable of K'ing 8-10 a game, and if he has his control in check, he's really good. His last start in Milwaukee, known for being a hitter's park, was very encouraging in that he lasted 7 and gave up only 1. With Penny and Lowe playing like Little Leaguers, his improved pitching has been huge.
After these 4, it's been a mixed bag of starts by Esteban Loaiza (bad), Hong-Chih Kuo (great), and Chan Ho Park (great). Loaiza is injured, and who knows what the plans for him will be once he's back considering that Park was really good in his only start, Jason Schmidt is making rehab appearances in the minors, and Clayton Kershaw will inevitably get the call to start. Kuo has actually been much better in the 'pen, where he's been lights out and a strikeout machine.
Seeing that their 3-4 starters are clearly outperforming their 1-2 starters, it could either be a good or bad sign, depending on your view. The good is that Penny and Lowe have good numbers in their careers, so they've got to figure things out at some point. The bad is that if they don't, it'll be really hard to make the playoffs. Here's to hoping that the former happens.