Baseball gave dating its base system, so these lines are working with the most established metaphor in the business. Getting to first, striking out, home runs — the listener knows the map, which lets the good lines subvert it instead of just reciting it.
The bleachers on a slow inning are the ideal delivery window: baseball's pace leaves generous room for conversation, which is arguably the sport's greatest contribution to romance.
Baseball rewards showing up every day, and its romance metaphors carry the same patience — the base system is a map of taking your time, and a strikeout is followed by another at-bat by design. That built-in forgiveness makes these lines unusually low-stakes: everyone knows the batting averages of even the greats.
The rest of the ballpark: basketball lines for a faster game, tennis for a season that never ends, and the full sports collection for every other field.

