Many a times I have seen while downloading a .torrent file the other client either snubs or not interested. Does anybody know why this happens? The possible reasons for it ? I have seen this both in small and large swarms so it doesn't seem to have anything either with the swarm size or how many seeders vs leechers it has (or does it ? )
Now AFAIK, the upload speed is directly symmetrical to your download speed (at least in some clients) so if you give 50 KB/s as your upload ratio then you would get the same or better download speeds and vice-versa. Does that also play into the decision-making of both the clients?
AFAIK after the tracker has made the hand-shakes with both the clients (as a broker in-between the number of seeders vis-a-vis the leecher the rest is to the individual clients.) its work is over and it's upto the clients to negotiate with each other.
Any explanation to what goes on as a negotiation between the clients and what factors are at play would be nice, mostly when one of them has pieces and is either choked or not interested - this is in public tracker where ratios don't really have a role to play.