I personally would never play -2.5....not saying it doesn't ever hit but it is very risky.
Moneyline plays are the way to go.
Be careful when laying too much juice ie; -320 on wainwright tomorrow against pirates. I'm not saying it will not hit, but if it misses then you just lost alot of money for a little gain.
Be careful if a play seems "too easy." These plays seem to lose more often than not.
Run lines can be money makers but again, dont go crazy laying RL's because you dont wanna lay big juice, quite often games are determined by 1 run. Also when playing a RL, betting the visiting team is alot better if it's a -1.5 because the game does not end when they pull ahead by 1. If you bet the home team at -1.5 and it's in the bottom of 9th or better your only chance is a walk-off homerun.
.......just my 2 cents