In my opinion, if you deem a play to have value (+EV), then play it. Some days there will be one, some days there will be five. Don't set limits on # of plays per day because if you do that you'll add some poor value and skip some strong value along the way which hurts your bottom line. Just make sure your plays are +EV.
Have an idea going in how many plays per season you plan on wagering and how much bankroll you can afford to lose, and set an appropriate % for each game. If someone has 100 plays a year they can bet much more per game than someone who plays 1000 games a year.
Make sure you shop for the best lines!