In the box-seat/s
To be in the box seat or seats is to be in an advantageous position and dates in this figurative sense from the mid-19th century. There are two theories about the origin and both equally plausible. The first is that it derives from the box seats in the theatre, which are the best seats and afford the best view. The second is that it derives from the driver’s seat, or box seat in horse-drawn carriages. These were known as box seats from the 17th century onwards because there was usually a box or compartment underneath the driver. They were also elevated to give the driver better visibility. The OED maintains the figurative use of the expression is found mainly in Australia and New Zealand. The intense sporting traditions in these countries favours the box seats in theatres and sports stadiums rather than the more obscure reference to bygone horse-drawn carriages.