Formula Help

[clouds_kid]

I'm running a league but I can't figure out how to make a formula for it.

1 point for every $1 in buy-in
2 points for every knock out (hit).

Points based on ranking. Please follow this down. 1 = Last place, and the last number would be first based on the total number of players. Or you could use the first number as the order out (1=first, 2=second).

1 - 0
2 - 1
3 - 3
4 - 6
5 - 10
6 - 15
7 - 21
8 - 28
9 - 36
10 - 45
11 - 55
12 - 66
13 - 78
14 - 91
15 - 105
16 - 120
17 - 136
18 - 153
19 - 171
20 - 190
21 - 210
22 - 231
23 - 253
24 - 276
25 - 300
26 - 326
27 - 352
28 - 379
29 - 407
30 - 436
 

If someone could help me figure that out, I'd appreciate it alot. 

Thanks,
Chris

[Corey Cooper]

(-.0000000000000019984 * pow(r, 3)) + (.5 * pow(r, 2)) - (0.5*r) + .0000000000000066134

It gets off by one at rank 26 and above, but it's pretty close:

1st, 0.00
2nd, 1.00
3rd, 3.00
4th, 6.00
5th, 10.00
6th, 15.00
7th, 21.00
8th, 28.00
9th, 36.00
10th, 45.00
11th, 55.00
12th, 66.00
13th, 78.00
14th, 91.00
15th, 105.00
16th, 120.00
17th, 136.00
18th, 153.00
19th, 171.00
20th, 190.00
21st, 210.00
22nd, 231.00
23rd, 253.00
24th, 276.00
25th, 300.00
26th, 325.00
27th, 351.00
28th, 378.00
29th, 406.00
30th, 435.00

[Corey Cooper]

Sorry, brain fart.  Try this:

(0.5*pow(n-r+1, 2)) + (-0.5*(n-r+1))

I also removed those parts with the very small coefficients, since after rounding, they are basically 0 anyway.


1st, 435.00
2nd, 406.00
3rd, 378.00
4th, 351.00
5th, 325.00
6th, 300.00
7th, 276.00
8th, 253.00
9th, 231.00
10th, 210.00
11th, 190.00
12th, 171.00
13th, 153.00
14th, 136.00
15th, 120.00
16th, 105.00
17th, 91.00
18th, 78.00
19th, 66.00
20th, 55.00
21st, 45.00
22nd, 36.00
23rd, 28.00
24th, 21.00
25th, 15.00
26th, 10.00
27th, 6.00
28th, 3.00
29th, 1.00
30th, 0.00

[lujo]

Nice formula, I have been looking for one.

But isnt it to little points for first place? There isnt much between first and second, should it not be a little more advantage to win?

Im a sucker at formulas like this and if i wasnt i may have come with a suggestion my self.. 

[clouds_kid]

I've actually ran the league for 3 weeks now and you can start to see a seperation between the rocks and the people that just play to play.  The whole uh, formula, and the way my league is designed is to allow people to sit around and fold hands and still make the final championship.  It's not that big of a difference between first and second, but it adds up after twenty weeks of play.

[jellygoose21]

I like the idea of this formula...
I posted the one before hand, this is what i want to do with mine.
But have a % of points given out to the players, based on how many players there are.
I have taken this formula... and have been trying to change it... but no luck as yet.

My other option is the setup the formula like Corey advised... and when we get extra players,
i just give out 1/2 of the points for last place to those players.

I'm running a league that is 20 weeks long, but only yuor best 10 weeks counts.
The the points willl be added up, multipled by a number and given to the players in chips
for the grand final, so that every one gets a chance to win the GRAND FINAL PRIZE!