Astros are 3-5 in Oswalt starts this season and just 5-9 in his past 14.
Zito has had some tough outings, but biggest challenge has been run support - Take out final two games last September (when they got 20 runs) and Giants have scored exactly 29 runs in his other 15 starts
Astros have won three in a row Away (sweep of LAD)
Since late 2005, they've won three in a row Away 11 times and then won the following game just twice (1 of 9 when that game was Away).
Best of luck however you elect to proceed