Most championship events decide who gets the pick of last rock (the hammer) with a last stone draw (LSD - I don't know who chose this name). At the end of each team's practice period, two different players throw draw shots - one clockwise and one counter-clockwise. An official measures the distance of each rock to the pin (to the nearest eighth inch) - zero if the rock covers the pin. If the rock misses the house, the measurement is 73 inches. The sum of the two measurements is the LSD.
The average LSD (discarding the highest one) for a team is its Draw Score Challenge (DSC). Other factors being equal, this can determine seeding within playoffs. A team cannot be eliminated from playoffs based on DSC.
Before the 2015 season, one of its players (usually the skip) throws a draw shot. The measurement of the nearest part of the rock to the pin (to the nearest eighth inch) is the LSD. If the rock covers the pin, the LSD is zero. If the rock misses the house, the LSD is 73 inches.