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Subway officials in New York City held a news conference recently to celebrate the system’s progress. The on-time rate for trains hit 76 percent, they boasted, signaling a “renaissance” for the floundering system.

But that figure masks a surprising disparity.

While the numbered lines have seen a notable boost in reliability, many of the lettered lines are still delivering poor service. The F train has a miserable on-time rate of about 50 percent — the lowest in the system.

“It seems like there’s always something, from a sick passenger to signal problems,” said Paul Galloway, an F train rider who lives in Brooklyn and works at the Museum of Modern Art. “It just seems like a cursed line to me.”

It is clear that the subway is improving after hitting rock bottom in the summer of 2017, when a train derailed in Harlem and the on-time rate dipped below 65 percent — the worst of any major transit system in the world. The subway’s leader, Andy Byford, has won accolades for making the system more reliable.