KWSN Orbiting Fortress

[shoob]

Having not crunched (or shrubbed, as the case may be) for a team before, I was never really concerned (interested?) in RAC. I just crunched what I wanted to. That has changed now, what with all the challenges, and tanuts, and bears! Oh my! So, my lame question of the week is:

How "recent" is Recent Average Credit (RAC)? In other words, is it an average of the last week, two weeks, month? Every stat site I constantly refresh on an all-too-frequent basis has a different RAC...I assume each site uses it's own formula, which I don't understand because WU credit is determined by the project, not the individual stat sites, right? And knowing that all of them are different, which is the best/most accurate to go by? I've been back and forth between boincstats and stats.free-dc.org.

Anyway, help a Knight out, would ya'?

nu!
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[Lloyd M.]

Shoob,
Not a "dumb" question at all. I still remember how long it took me to figure out the meaning of the acronym, much less how it works.

The average is a rolling one, and how far back varies, though you can count on about two weeks, plus or minus.

The RAC can average per site/project, and is also averaged across projects using your cross-project ID (CPID)

One thing you will notice is that the averages (and even the TC) will NEVER quite match between the sites. One presumes the project site is the definitive one as far as TC, and I don't think there is any real consistency as far as how RAC is calculated site to site.

I like using BOINC statistics for the World! for world standings, and team starfire World BOINC Stats n' Stones for most everything else. It has good overtake statistics (called "stomp" on their site, with a little boot icon), and also join date stats, pretty good graphs, etc. What I really like is the simple but effective chart of TC per day, per project, linked to a page with per shubber per day for that project.
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[Al Dente]

RAC is actually an exponential function with a half-life of 7 days; e.g. if you start shrubbing a project at a constant 100 cobblies/day, then after 7 days your RAC will be 50, after 14 days 75, after 21 days 87½, etc. It takes ~ 6 weeks to get to 95% of its final value. The projects actually calculate it to the nearest second when your credit is granted.

If you stop shrubbing a project, they're meant to decay the RAC figures, but some projects only update RAC if you shrub, so this can distort the figures. I know that BOINC Synergy calculate the RAC, but AFAIK the other stats sites just use the figure supplied by the projects.

The BOINCStats RAC is an average of your last 60 days (real) RAC.

The Ni!RAC on ohiomike's stats is the same as RAC, but using a half-life of ~1½ days, so it reaches 95% of its final value in 7 days (i.e. a faster reacting version, better than (real) RAC for overtake calcs).

BOINCStats use some sort of complicated formula involving RAC, BS-RAC, and your last month's and week's shrubbing to work out their overtake figures; Free-DC use a 7-day average and most other sites use RAC.



There you are - clear as unto mud.


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Creationists believe they never evolved; I agree with them.

. . My Milestones . . My Full BOINC list

[shoob]

Thanks for the detailed explanations!

hmmm, didn't realize it was so complicated. Seems to me that Recent Average Credit would be an "average" over a certain amount of time, say one week (a week is kind of "recent"). Not dealing with all of those half-life stuff, or even calculated over a month, but I guess "recent" is subjective, considering these projects are meant to last over years.

I would assume this complicated "half-life" formula was created to prevent users from shrubbing a project for a week just to get a Top 10 status, right?

nu!
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[Al Dente]

Not sure about that.

The main advantage is that if you swap around projects a lot (like I am wont to do), your total RAC stays much the same (assuming the projects give similar credit, which almost never happens); as one project goes down others go up.

With a, say, 7-day average, there are sudden jumps as scores move out of the averaging window (i.e. become the 8th day).




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Creationists believe they never evolved; I agree with them.

. . My Milestones . . My Full BOINC list

[Killerrabbit]

I have never understood the calculation RAC myself and I have been with BOINC from the beginning.

Ni
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[Old woman(mann, sorry)]

You could just ignore the whole thing.
The important point is that you're doing your bit for the benefit of everybody n'est pas?
The stats can be seen as little boys seeing how high they can piss up a wall (sour grapes because I only have an Athlon 2000 perhaps).
I enjoyed Al Dente's explanation though.
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[img]http://boincstats.boincstats.com/search/all_projects.php?cpid=8fbcb4ce48ba412ccbb4337d9d2bf18a.gif[/img]

[Killerrabbit]

Well my RAC is at least higher than yours.



Ni
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[Lloyd M.]

[Sir Hamster of Elderberry]

I cannot believe no one has taken the opportunity to post pictures of Lame Racks.
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-- Have you seen my goat?

[John Galt 007]

See the NSFW thread...nice RACs in there...
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http://stephenbrooks.org/muon1/banner.php?user=[KWSN]John%20Galt%20007
http://stats.free-dc.org/mosttag.php?cpid=f7e8c5dfbccfce7e6054e7a84c151aa4&theme=4.png

( • )Y( • )

[Fart in your gen direxion]

Here's my RAC . Good thing I've been working out, I used to be real sloppy .


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Ni ! Ni !

Flatulenty yours,

Sir Fart

The Prince of Noxious Fumigations
The Earl of Eruption
The Baron of Breaking Wind
The Marquis of the Malodorous
The Monarch of Methane
Loony Emeritus

[KWSN SpongeBob SquarePant]

Sir Fart!

You have lost weight!

Down to a DD now. Nice!

SBSP
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Ni!

<br><br>
http://stats.free-dc.org/mosttag.php?cpid=e4befed74f2fd0e20845d7958a1ffbbe&cols=3

[PhastPhred]

If THIS is 'Tatas@Home', I think I'll pick another PotM!