How do I get better numbers from my starters?

My four man rotation for 2013 is Bumgarner, Darvish, Griffin and Samardzija. Other than Darvish, my staff is way underperforming their cards. They all have ERA's over 5.00 and it's not like they get tired and hammered late. They all give up the runs early in the game. Is there anything that can be done?

I'm still trying to figure this strat thing out and it is frustrating.

Others who play more teams than I do can probably give you more detailed answers, but a couple of things I'd look for first are:
Your rolls - sometimes you'll find a series of lopsided ones, where pitchers are getting very few results on their own cards.
Your ballpark - maybe your staff doesn't fit well where they pitch most often (even worse, maybe they don't fit well in any of your division opponents' parks, either). Guys with lots of BP effects can get really out-of-range results in some parks.
Your opponents' lineups (especially in your division) - maybe your staff just doesn't match up well with the guys they're seeing most often.

If you want to see pitchers really underperform, though, try ATG.

My four man rotation for 2013 is Bumgarner, Darvish, Griffin and Samardzija. Other than Darvish, my staff is way underperforming their cards. They all have ERA's over 5.00 and it's not like they get tired and hammered late. They all give up the runs early in the game. Is there anything that can be done?

I'm still trying to figure this strat thing out and it is frustrating.

1. Hitters are much better than your pitchers faced in real life. On average, they will underperform. Keep in mind, hitters face the same dilemma and will,on average, also underperform. The higher the salary cap, the worse it gets for both hitters and pitchers.
2. You may have more hitters parks than your pitchers faced in real life--especially if you play in a hitters park!
3. If you have national league pitchers, they are now facing a DH, unlike in real life.

If you like to see pitchers perform closer to real life, you might try the 60s Superstars. Also, any $60 million league is good for getting more realistic results. However, they are rare and sometimes hard to fill.

Some people will point out that SOM's online results as unrealistic, but in fact they give a good idea of what to expect if real life was played under the same conditions as the online game (i.e., only twelve teams, stronger teams than real life teams, more hitters parks).

My four man rotation for 2013 is Bumgarner, Darvish, Griffin and Samardzija. Other than Darvish, my staff is way underperforming their cards. They all have ERA's over 5.00 and it's not like they get tired and hammered late. They all give up the runs early in the game. Is there anything that can be done?

I'm still trying to figure this strat thing out and it is frustrating.

Can't tell anything without a link to the team page

In my opinion, a 5.00 ERA for Griffin or Samardzija is not exceptionally bad for average or hitter's parks. But a lot goes into it: besides the items mentioned earlier, what kind of fielding do you have? A bunch of 3's and 4's will also contribute some earned runs into the mix.

Here's the team.

http://onlinegames.strat-o-matic.com/team/1387329

I tried to get hitters with good OBP, solid defense and position flexibility. Put them in Dodger Stadium. Also tried to get value pitchers to take advantage of the large park. This is my first time playing Strat so not sure if this was a good strategy or not.

One thing, by not using Zobrist as your 2bman, you're paying a premium for that 1 e6 but not using it.
Other observations
1.Samardjia is a bum, the rest of your pitching looks pretty good to me.
2. Not enough lefty hitters in a lefty park

Be sure to set you D and E base stealers to not steal on the Hitters Preferences pages. (In fact, I usually do the same for C base stealers.)

Here's the team.

http://onlinegames.strat-o-matic.com/team/1387329

I tried to get hitters with good OBP, solid defense and position flexibility. Put them in Dodger Stadium. Also tried to get value pitchers to take advantage of the large park. This is my first time playing Strat so not sure if this was a good strategy or not.

There are a couple thing off the bat you should understand.
1) Your fifth wheel starter Hand is killing your bullpen. Your 5th starter in a 4 man rotation should be an exclusive starter not a SP/RP as cheap as possible.
2)You have right handed hitting guys like Jones and Longoria who are getting neutered by your LH biased stadium. You always want to use the BP Homerun # and BP single > to your advantage. They are fine cards, but wrong for your stadium.

Thanks for the tip on playing to my stadium. I didn't take that into account. Replaced the 5th starter and added Cano in place of Longoria. Hoping that will make a difference and I can get out of last.