Another tip if going by you're self. 10 or 20 minutes before game time stand around the entrance where season ticket holders go, for the nice seats, would come in. Open you're mouth and ask if anyone has extra or extras. Afternoon games especially as business people get the ticks comped and usually last minute and may not be able to fill all the seats. If they ask, make sure you say you are not reselling them.
Half the time they give them to you. I will offer money for a beer but that is it. Some laugh, most do not, but if you are a good person and have free tickets it is not a $ making affair for you.
We used to do this with almost 20 people at times. Rarely did we not get enough tickets, however they were spread around the stadium. The objective is just to get in. But, with the connections you make, you will go to you're usher friend and he should let you sit where there is room.
Obviously would not work for high profile games.
Have even done this same thing at other stadiums. Fenway, St.Louis and many games in spring training.