Mathematics of torrenting...

[campodetenis]

It's been a while since I was wondering how do seed-leech ratio works on tracker level. I mean, there must be an intrinsecall unbalance between quantities, as there is at least one more leecher than a seeder right?

Lately I've heard a lot of "economics" when talking of free leech and stuff, and I'm trying to figure this term out.

At the end, how come a file can survive the whole seed/leech process?

Other thing that bothers me is the site stats. How come the seed/leech ratio is calculated? Is like "potential seed" or true seed?


P.S. I know, I know, I'm such a geek.

[campodetenis]

Will do, but then I'll come up with some "what am I doing here?" "where did I parked my car?" sort of questions...

[IceTee]

smoke some weed

LMAO

Will do, but then I'll come up with some "what am I doing here?" "where did I parked my car?" sort of questions...

ahhh... how I miss those days

[cubkiller89]

smoke weed everyday

[bikernin]

excellent advice. this is the best place to come for advice

[apunpktun]

I am guessing he has already smoked some to come up with questions like those.... (not tht i am saying it from experience)

[mrnobody]

It's been a while since I was wondering how do seed-leech ratio works on tracker level. I mean, there must be an intrinsecall unbalance between quantities, as there is at least one more leecher than a seeder right?

funny enough that i asked myself this question too.

Some tracker refer it as "seed:leech ratio" and some as "seed:leech ratio (%)"...but the second one makes more sense despite the fact that % goes 100+

here is how it works...

Example:

Peers14,471
Seeders14,120
Leechers351
Seeder/leecher ratio (%)4023

(Ratio) * 100%

sdsSeeder
= _______ * 100%

sdsLeecher

14,129
= ______ * 100% = (40.22792023) 100% = 4022.792023

351ssssdsssssssssssssssssssssssssssssss= 4023


and btw, there are more seeder in tracker than leecher. It makes sense in an established tracker...there are thousand of torrent alive (mainly because of seeder).

[campodetenis]

I agree, but at the end there will be someone with the file and a negative ratio (cus he's the last leecher) and nobody to pass it on. So what happen's then?


(my hypothesis is that is always the guy who smoked some weed and ends up creating "why am I disabeled" topics)

[Showtimextx]

smoke weed everyday

Or even every other

[bikernin]

ok lets do some math..
we will start with a small sample space of 10 users and 10 torrents.
assume that 1 user is an uploader and 10 are leechers.
uploader has uploaded 10 torrents. all 9 users leech the 10 torrents
so initially, seeder/leecher ratio = (10*1)/10*9)=1/9
so yes, at a certain point of time there can be a S/L ratio <1
as the leechers start finishing the torrents the S/L ratio will keep growing till we finally reach a stage when everyone has finished downloading the file.
at this point S/L=(10*10)/(10*0)=infinite
these are ideal situations. expand the sample space to a userbase of thousands. you are always bound to have someone downloading a torrent so we never get to an infinite ratio. and on good sites the time it takes for a user to complete a torrent is very less because of high speeds and more seeders. due to this leechers are quickly converted into seeders. so at a given point in time, on a good site, there will always be more people seeding than leeching and no. of leechers will always be decreasing faster as compared to no. of seeders. (seeders reduce only if they stop seeding the file and most sites have strict policies for hit and runs ensuring that people seed long)
hence we have a very high seeder/leecher ratio
to illustrate the last few lines, lets take an example.
if i download a movie in 5 hours, ill normally seed it for atleast 2 days
so i was a leecher for 5 hours, but was a seeder for 48 hours. this is what i usually do. most people have upload speed half of download speed. so if they get a file in 5 hours they seed for atleast 10 to get a ratio of 1. which again means they were seeders for a longer time and hence according to probability theory, at any point in time, the probability of having more seeders than leechers is very high
P.S : that was some good weed !