Almost no flights are held back for connections. There's probably the odd flight that is held back if there's a large number of passengers that will miss it du

Almost no flights are held back for connections. There's probably the odd flight that is held back if there's a large number of passengers that will miss it due to a late connection--and there's no later flights with seats available. I would imagine the cost of holding the 11pm LAX-SYD flight because 20 people are 10 minutes late on the NYC-LAX connection is a lot less that paying for hotels, especially when the next flight may not have 20 seats available anyway. Though then again, most carriers have gate pressure at LAX and they might not be able to hold the flight anyway. It's an interesting optimization problem to solve!