In college, I would pay every one of my bills from April through August on nothing but gambling on baseball.
You have to be able to read the lines. Almost every day Vegas will give one away with how they juice the game. A bad road team with their crap starter on the hill vs someone's Ace at home and they aren't nearly the + they should be, or are EVEN or occasionally sometimes even favored -- that's Vegas trying to get people to not take the game. There's also the slam dunks, like taking a -280 against a +180, which should hit the vast majority of the time (but you're going to be paying quite a bit more than you're winning).
Are you betting the 1.5 Run lines or just picking winners? The latter is worlds easier than the former. Also, if you're taking Over/Unders, the crazy high lines like 9+ tend to hit a ton on the over, especially if there's extra juice on them, in my experience, and if you want a good prop bet find a game between two light hitting teams or with two Aces facing one another and bet that no runs will be scored in the 1st inning.
If you have an account with Bodog (
http://www.bodoglife.com), you can go into match ups and see how the teams have trended against each other (who has covered, when the over has hit, so on and so forth). It's never as simple as just using one piece of data (as in your example) to make a decision. If you want to make money you've got to be willing to do the research and put the time in.