Playing a hitter in LA might not be a great idea if you have a comparable alternative in another park. Opposite goes for a pitcher in LA. And Colorado is well known to be a big hitter's park. Playing a pitcher in Montreal, or against Montreal, is a good idea. They havn't scored 4 runs in a game yet, and have a very weak offense. Those are pretty much the extremes. You can check out park indexes for which ones favour hitters/pitchers, because there are too many to go over off the top of my head. But Oakland/Seattle/Detroit/SF/NYM play in pitcher's parks, and Hoston/Toronto/KC/Cincinnatti play in hitter's parks. Other things to consider are who's on the mound, and how good the opposing team's offense is for hitters and pitchers, respectively.
"Jack, will you call me, if you're able?"
"I've got your phone number written, in the back of my Bible."