user19877: I am watching the Fischer Random World Championship with Magnus Carlsen and Wesley So, and I am wondering how they determine the starting position?
Is it software that picks, or do they start left to right, and pull pieces out of a bag? Or is it some other way?

user19281: Many professional-grade chess clocks are capable of randomly choosing a valid Chess960 starting position and describing it to the players.  I suspect that in many tournaments, this is how it's done.
It is also possible to choose the position using other sources of randomness, such as rolling dice.  Standard gaming dice sets include not only 6-sided cube dice (known as d6), but 8-sided, 10-sided, 12-sided, 20-sided, and 4-sided types as well.
A Chess960 position can be fairly chosen using 2d4 of contrasting colours (to choose the positions of the bishops), a d6 (to place the Queen on the remaining squares), and a d10 (to place the knights).  The rooks and king are placed on the three remaining squares, with the king in the middle.  This procedure also corresponds to the method of deriving a position from a position ID outlined here.

user20454: 8.4.3. Drawing of positions
● Set up of the pieces will be decided by a drawing made by Fischer Random Generator
software with all players present 15 minutes before the start of the first game of
each time control. This setup then will be used for both games. The players will
attend this drawing, and will then be given time before the start of play to confer
with a second.
Found in the download here: https://www.frchess.com/regulations
Interestingly, if the classical position is picked then they pick again.

19877: <p>I am watching the Fischer Random World Championship with Magnus Carlsen and Wesley So, and I am wondering how they determine the starting position?</p>
<p>Is it software that picks, or do they start left to right, and pull pieces out of a bag? Or is it some other way?</p>
 19281: <p>Many professional-grade chess clocks are capable of randomly choosing a valid Chess960 starting position and describing it to the players.  I suspect that in many tournaments, this is how it's done.</p>

<p>It is also possible to choose the position using other sources of randomness, such as rolling dice.  Standard gaming dice sets include not only 6-sided cube dice (known as d6), but 8-sided, 10-sided, 12-sided, 20-sided, and 4-sided types as well.</p>

<p>A Chess960 position can be fairly chosen using 2d4 of contrasting colours (to choose the positions of the bishops), a d6 (to place the Queen on the remaining squares), and a d10 (to place the knights).  The rooks and king are placed on the three remaining squares, with the king in the middle.  This procedure also corresponds to the method of deriving a position from a position ID <a href="https://en.wikipedia.org/wiki/Fischer_Random_Chess_numbering_scheme#Direct_derivation" rel="nofollow noreferrer">outlined here</a>.</p>
 20454: <p>8.4.3. Drawing of positions</p>

<p>● Set up of the pieces will be decided by a drawing made by Fischer Random Generator
software with all players present 15 minutes before the start of the first game of
each time control. This setup then will be used for both games. The players will
attend this drawing, and will then be given time before the start of play to confer
with a second.</p>

<p>Found in the download here: <a href="https://www.frchess.com/regulations" rel="nofollow noreferrer">https://www.frchess.com/regulations</a></p>

<p>Interestingly, if the classical position is picked then they pick again.</p>
