PeteW
Joined: Aug 05, 2005
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 Posted:
Apr 19, 2006 - 11:23 |
 
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...or am I innumerate?
I got beaten by Malthor in the recent Amazon XFL semi-final (grats Malthor, no great surprise though!) Now, my CR dropped by 5 whole points, which thought was a bit harsh, cos his TS was 50 more than mine. So I checked the calculations...
My CR before = 177
Malthor's CR = 176
dR = -1
My TS = 226
His TS = 280
dT = 54
Number of teams in competition = 32
K = 2 sqrt(32) = 11
Now for the tricky bit!
p = 1 / ( 1 + 10^(dR/40 + dT/70) )
= 1 / ( 1 + 10^(0.746) )
= 1 / 6.57
= 0.152
Lastly,
New ranking = 177 + 11 * ( 0 - 0.152 )
= 175.33
Not 171.6 !!!!
Now, I'm not too fussed about my CR, but I thought that I'd better check my maths with you guys before I tell Christer that there might be something wrong with his site!
Thanks for your help!
PeteW
The game link is http://fumbbl.com/FUMBBL.php?page=match&id=1169662 if you are interested |
_________________
"Jesus loves me this I know, 'cos my Bible tells me so." MrMojo - where did you go? |
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koadah
Joined: Mar 30, 2005
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| Posted:
Apr 19, 2006 - 11:31 |
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Nature_Warden
Joined: Feb 10, 2006
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| Posted:
Apr 19, 2006 - 11:32 |
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*Rubs his eyes furiously*
...I... CR? How does... 2+2? Time defraction due to the friction of the planets gravity well on the space-time continuum?? What... TS... you? Who...? ...who wrote? That's how they? CR is dumber then I thought!? |
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MiBasse
Joined: Dec 04, 2004
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| Posted:
Apr 19, 2006 - 11:40 |
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It's all due to the fact that there's additional measures to take into account for official tournaments - the bonus to CR is far greater but so is the loss. I'm not entirely sure how big the differemce is but it's VERY substantial. |
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PeteW
Joined: Aug 05, 2005
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| Posted:
Apr 19, 2006 - 11:42 |
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RedFish, the difference for the tourny is in the K-value.
K = 2*sqrt(number of teams)
So for RRR it is 8, and for SMACK it is 6.
And for this XFL, as there are 32 teams, it should be 11. So this accounts for the big shift, but according to my calculations it shouldn't be as big as it was. |
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"Jesus loves me this I know, 'cos my Bible tells me so." MrMojo - where did you go? |
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Curro
Joined: Jun 07, 2005
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| Posted:
Apr 19, 2006 - 11:43 |
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/me voted that he (PeteW, not Curro) is a n00b and deserves (PeteW, not Curro) to be crushed by Malthor, cause he (Curro, not PeteW, neither Malthor) has no idea about maths and the CR calculations. |
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Candlejack
Joined: Aug 02, 2003
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| Posted:
Apr 19, 2006 - 11:53 |
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i think i found a mistake in your calculation.. the dT Value is not just (Your TS - His TS) it is defined as
| Quote: |
dT = Normalized difference in team strength ( 100 * [s1/min(s1,s2) - s2/min(s1,s2)] )
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in the referenz section
and if i put your TS as s1 and his a s2 (it does not really tell which TS value goes where but that seems the most logical choice to me) it becomes
| Quote: |
dT=100*(226/226-280/226)=-23.8938...
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at least the ranking explanations reads like that to me, if i'm wrong someone please tell me |
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moxjet
Joined: Dec 27, 2003
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| Posted:
Apr 19, 2006 - 11:59 |
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It looks to me that your math is good this time 
Definitely should be 175.33 .... according with your numbers |
_________________
"I love it that buskopanz plays with just one GR, which is usually one of the lowest in spps of the team" Garaygos |
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sk8bcn
Joined: Apr 13, 2004
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| Posted:
Apr 19, 2006 - 12:02 |
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yes you are wrong, pete: dT is a normalised value so:
http://fumbbl.com/help:Ranking
we have dT=100*(226/226-280/226)=100*(-54/226)=-5400/226=-23.8
so overall:
for you -1/40+23.8/70=0.315
grrrrrrrrrrrrr..........
candle has been quick...crap, no need to continue
edit, bah let's end: |
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moxjet
Joined: Dec 27, 2003
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| Posted:
Apr 19, 2006 - 12:08 |
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even with the new DT we should have new CR = 173.42 ...not 171.6 |
_________________
"I love it that buskopanz plays with just one GR, which is usually one of the lowest in spps of the team" Garaygos |
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sk8bcn
Joined: Apr 13, 2004
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| Posted:
Apr 19, 2006 - 12:11 |
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| sk8bcn wrote: | yes you are wrong, pete: dT is a normalised value so:
http://fumbbl.com/help:Ranking
we have dT=100*(226/226-280/226)=100*(-54/226)=-5400/226=-23.8
so overall:
for you -1/40+23.8/70=0.315
grrrrrrrrrrrrr..........
candle has been quick...crap, no need to continue
edit, bah let's end: |
p=1/(1+10^.315)=1/(1+2.06)=1/3.006=0.33
after that 11.5*.33= 4 roughly.
I admit that some roundings in your own CR and my calculations explain the rest. |
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PeteW
Joined: Aug 05, 2005
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| Posted:
Apr 19, 2006 - 13:00 |
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Thanks guys!
I guess I am a n00b... sniff.. sniff... |
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"Jesus loves me this I know, 'cos my Bible tells me so." MrMojo - where did you go? |
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sk8bcn
Joined: Apr 13, 2004
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Apr 19, 2006 - 14:14 |
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Well It points out a flaw in a CR formula though, IMO.
The normalisation is way, for me, too say: "well at high TR, TS becomes less accurate because there can be many combos and skill uses that can't be perfectly evaluated.
A 20TS diff at high TR just isn't the same as 20 TS diff at low TR.
However, this normalisation reduces TS effect at high TR: e.g. Pette's game: from 56 TS diff, it becomes a 23 TS diff. That's a huge change that I can understand.
But I do not agree with the second reduction dT/70 when we have dR/40.
As circ spoke about many time. TS diff is IMO underrated by making 2 decreases of dT in a row:
-the normalisation
-the division per 70 instead of 40 |
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Mezir
Joined: Aug 02, 2003
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| Posted:
Apr 19, 2006 - 14:27 |
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Without that change, we'd be back at having people with CR 230 and still climbing. As it is now, we have people reaching 190, then dropping back into 180, with nobody ever managing to permanently stay above 190.
Given the mathematical nature of the ranking formula, this is exactly what it's trying to achieve, and as such, it is doing a good job right now.
See also: Elo Rating System |
_________________
Build a man a fire and he's warm for a day; set a man on fire and he's warm for the rest of his life. |
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Webbe
Joined: Aug 13, 2003
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| Posted:
Apr 19, 2006 - 14:43 |
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| Mezir wrote: | | Without that change, we'd be back at having people with CR 230 and still climbing. As it is now, we have people reaching 190, then dropping back into 180, with nobody ever managing to permanently stay above 190. |
Just give me some time aight? |
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