How/Why are the full game any% runs starting at the Tributary Championship?

The career mode requires a certain position in the FedEx Cup standings by certain points in the season schedule.

First, the playoffs require 125th position or better by the end of the regular season, which is easily cleared by winning a single regular season event. As of now, the last regular season event is the Tributary Championship, which is used currently because there is no simulating time needed if that event is taken, as timing starts on gaining control of the golfer.

Second, each playoff event has a certain cutoff to reach the next event (70th in FedEx Cup standings to advance to Trios and 30th to advance to the Tour Championship). Both of these are cleared by winning the Northern Trust, the first playoff event. The current route takes you to the Tributary Championship, then the Northern Trust, then simulating past the Trios by withdrawing and playing the Tour Championship.