I do not know what the criteria is and I doubt the pool know.
As it’s a DNS query that rotates, see for yourself:
bas@workstation:~/Bureaublad$ nslookup pool.ntp.org
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: pool.ntp.org
Address: 185.111.204.220
Name: pool.ntp.org
Address: 109.68.160.220
Name: pool.ntp.org
Address: 162.159.200.1
Name: pool.ntp.org
Address: 162.159.200.123
So if you want a pool more close to you, then select a diffent pool like europe:
bas@workstation:~/Bureaublad$ nslookup europe.pool.ntp.org
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: europe.pool.ntp.org
Address: 80.151.151.109
Name: europe.pool.ntp.org
Address: 84.16.73.33
Name: europe.pool.ntp.org
Address: 88.99.76.254
Name: europe.pool.ntp.org
Address: 51.15.182.163
Or even more close, in my case Belgium:
bas@workstation:~/Bureaublad$ nslookup be.pool.ntp.org
Server: 127.0.0.53
Address: 127.0.0.53#53
Non-authoritative answer:
Name: be.pool.ntp.org
Address: 45.87.76.3
Name: be.pool.ntp.org
Address: 162.159.200.1
Name: be.pool.ntp.org
Address: 162.159.200.123
Name: be.pool.ntp.org
Address: 185.111.204.220
Just depends on how big a pool you want to use.
It rotates and it can’t know what to give you, as such there are more local pools.