AA 1253 then AA 2072 at San Francisco
Chicago O'Hare → San Francisco → Los Angeles
Timetable, San Francisco time
09:40AA 1253 from Chicago O'Hare at the gatealso QF 4697
13:28AA 2072 to Los Angeles leaves the gatealso QF 3051, IB 4847
3 h 48 apart on the timetable
The last days
AA 1253 and AA 2072 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.