Originally Posted by
nocharge
.. In reality, you will likely fly a little further than that due to directional constraints for take-off and landing and the pilot might deviate from the great circle course for jet stream reasons. Will UA keep track of that and give you the extra credit you deserve? ....
The great circle distance is what is used by all airlines. That has been the standard since the beginning of these programs -- anything else would be an unpredictable , unverifiable nightmare.
Also the programs use the standard promised distance even if
Mileage credit for IRROPS / diversions / return to airport / .... ?