How a restaurant takes bookings determines how much of its capacity it can actually use. The policies that guests experience as friendliness or rigidity are mostly capacity arithmetic.
Empty seats cannot be recovered later
A restaurant's product expires continuously, since a table unoccupied at eight o'clock cannot be sold at nine as well as the nine o'clock booking.
That makes the peak two or three hours of an evening the period in which most of the day's revenue has to be earned.
Every policy around booking exists to get as many paying guests as possible through that narrow window without degrading the experience.
Table mix decides how much capacity is wasted
Seating two people at a table for four wastes two covers for the whole sitting, and doing that repeatedly can waste a significant share of a room.
Because pairs are the most common booking, rooms are increasingly built with many small tables and a few that can be joined for larger groups.
Reservation software solves this allocation continuously, which is why an online system will sometimes refuse a time that a glance at the room suggests is free.
Sitting length is planned, not discovered
To seat a table twice in an evening, the first sitting has to end within a known period, so the kitchen and service are paced towards that duration.
Stated time limits make the plan explicit, and where they are not stated the same plan is implemented through the pace at which courses arrive.
Restaurants that decline to turn tables have to earn the whole evening's revenue from one sitting, which shows up directly in their prices.
No-shows are the largest uncontrolled loss
A guest who does not arrive removes a table that was refused to others and that cannot now be sold, so the cost is the full value of the booking.
Deposits, card details and confirmation messages all exist to shift that risk, and they became widespread as the loss grew relative to margins.
Overbooking is the alternative approach, and it trades no-show losses for the risk of guests waiting, which most restaurants judge the worse outcome.
Walk-in policy is a deliberate reserve
Holding some tables back for walk-ins keeps the room full when bookings fall short and captures passing custom that would otherwise go elsewhere.
Restaurants that take no bookings at all convert the queue itself into their buffer, filling every seat the moment it is free.
That approach maximises occupancy and pushes the cost of the wait onto the guest, which is why it suits places where the queue is short and the meal is quick.