Pitching.
Good pitching beats good hitting.
Streaks.
Even bad teams will go on an 7-8 game winning streak maybe once a year and pay off at + money every day.
Move the juice.
Lay 1 run on a -116ish favorite and move the juice to +108ish.
Know your bullpens.
Even good teams will have 1 or 2 guys that will give away games.
If you see a good number come out overnight, hit it. If you can wait, check the lineups first.
Pitching.
Good pitching beats good hitting.