Does order of servers in upstream directive matter ?

[Yusuf Goolamabbas]

>From my reading of the upstream directive documentation (albeit via babelfish)

http://sysoev.ru/nginx/docs/http/ngx_http_upstream.html

I can't determine if the order of server names/IP in the upstream
directive matter. does nginx balance the connections randomly
(assuming no weight's are provided or is it round-robin)
if I have 2 nginx instances should I keep

server A;server B; in one instance and server B; server A in the other instance

Thanks, Yusuf