Even though the batter is swinging at both pitches, they're moving fastballs inside the strike zone, so maybe they'll pitch on a four-seamer instead of a five. The batter swings at the first pitch, and it's a high and inside-bait pitch. The second pitch is a little higher, and the batter swings on it, too, even though the pitch is moving outside the strike-zone. He swings on the third pitch and it goes over the fence, and he's glad he did it, because it means that the gap between the two of them is just two points. He's worried that the batter will swing away and hit the infielders, so he tells his son to keep swinging hard, because they still have two runs to go.