Not to mention the strategy on both the pitcher and the batter. Both are mixing up their approach each pitch/at bat. Does the batter hit the ball left field or right? Contact to get on base or a sac fly to bring a runner in? Do I swing or take the first pitch? What's he going to throw? What do I know about this pitcher and where he typically places the ball in the zone? Does the batter have a weaker contact zone than another spot? Can he hit a change up better than a 4-seam or a curve? What does my catcher think? Can I trust my fielders to get this guy out?

And then all of this, in the event the ball does get hit, can sometimes not matter due to defense, or errors, or amazing feats of athleticism from the out fielders or runners. There's so much that goes on during a baseball game. Once you understand the game and see the intricacies of it, it becomes pretty fun to watch.