driver's seat

noun2

1. •
   The seat in a vehicle where the driver sits.
2. •
   (US, figurative) A position of control or dominance.

   • The veteran-laden Rams (12-4) are in the driver’s seat to win the N.F.C. West. Los Angeles will take the prize with a win against the 49ers at home or a loss by the Cardinals (11-5) to the Seahawks. — 2022