Topic: 2014 USD/mBTC Price Prediction Contest - page 19. (Read 21792 times)

FINAL RULES 2014-4-30, THE COMPETITION HAS STARTED!
Any changes after "FINAL BETA 2014-4-29b" are in this color.
Any changes after "FINAL RULES 2014-4-30" are in this color.

This is
2014 USD/mBTC Price Prediction Contest
, a probability prediction contest for monthly USD/mBTC rates for the rest of 2014.


* Entry ONLY 50mBTC
* 25%(rounded UP) of the players get at least DOUBLE their money back!
* The jackpot for the winner is MINIMUM 1,000mBTC


S T A R T I N G   S C H E D U L E

The competition starts with special schedule as follows:

2014-4-30

The final rules and Excel prediction sheet will be made available. Available NOW.

2014-5-5 Monday, 23:59 GMT

Deadline for entry. 50mBTC must be paid with previously PM'd satoshimessage to 1GFKAW5RunZtNEQ834wTmu4dBaYG8CRbDm.

2014-5-6 Tuesday 23:59 GMT

Deadline for 1st round predictions.



S U M M A R Y

- You are to forecast a probability distribution that USD/mBTC falls in a certain price range in a certain day. There are 80 price ranges that span all the possibilities from 0 to infinity. The sum of your probabilities must equal 100%. You get points if you had allocated a higher probability to the price realized than the consensus of the other competitors. If your probability was lower, you get negative points.

- The competition consists of 8 rounds, and in each round you are to forecast the price at the last calendar day of every month yet to come in the year 2014. Thus in the first round you give predictions for all the months between May and December, inclusive (8 months). In the last round you give only 1 prediction. Therefore the total is 36 (8+7+6+5+4+3+2+1) predictions.

- Entry fee is 50mBTC per entry. One entry is enough for all the 36 predictions. One person can have at most 5 entries. Me and my staff can not enter. It is possible to skip rounds or enter late, because skipped rounds (only) result in zero points, which is roughly the average result anyway.

- I donate 1,000mBTC to the prize pot, and all entry fees also go there. 20% (rounded up) of the entries still in competition at the closing of the competition win double their money back (100mBTC). The rest (minimum 60% of the prize pot) is given to the winners as jackpots as outlined below.



D E T A I L S

- The competition is administered by me, rpietila, or my staff (currently: nikke).

- To enter the competition, the entry fee must be paid upfront, to "5-Run" address: 1GFKAW5RunZtNEQ834wTmu4dBaYG8CRbDm. The entrant must send prior PM to me indicating the "satoshi-message" of her payment, eg. "BTC0.05000724" which serves as a makeshift way to distinguish between multiple payments of same size to the same address. This must be done latest the 3rd day prior to the month from which the entrant wants to start forecasting. NB: start of the competition is special schedule.

- 5 entries per person maximum, during the whole competition. This is hard to conclusively monitor, but if caught with cheating beyond reasonable doubt (the predictions will be cross-checked etc.), the entries will be disqualified. If an entry is disqualified for any reason (breaking this rule, or scoring -20 or less points), the entrance fee is forfeited. Non-submission of a round is not a cause for disqualification, but results in zero points for the predictions during that round, which is about an average score.

- I retain the right to limit the number of entries. Once put into place, the limit cannot be lowered, but it can be raised to make room for more entries later in the game. The current limit is 50 entries.

- The entrant downloads the Excel prediction sheet and fills his entry name (eg. "wachtwoord4") and round number. This information also needs to be encoded in the filename when submitting. That one file contains all the 8 rounds and 36 predictions, and the means of scoring them. The entrant sends it by email monthly to nikke ([email protected]), completed with the latest round of predictions.

- The price slots are as follows (note: decimal comma and values in mBTC):


- The task is to allocate the total probability of 100% to the slots so that the probability of at least 0.0001% (1 in 1 million) must be allocated to every price slot. Otherwise there are no restrictions. If the total is more OR less than 100%, it results in zero points for that predicted month but no other penalty.

- The slots are of the same width in the log scale, which means that the percentage change to go up a slot is always the same (12.2%).

- The goal is to allocate the probabilities such that you have a higher probability in the slot with the realized price, than the geometric average of the other contestants. It does not matter which probability was allocated to the other 79 slots that "didn't win".

- The reference price is the Bitstamp daily volume-weighted average of the last calendar day of the month. If the exchange closes or becomes dysfunctional, I may change the reference at my discretion. My discretion may further be overruled by 51% of the contestants.

- I retain the right to make further clarifications to the rules, with the veto of the majority as per above.

- If participating in this competition is against your law or conscience, don't do it.


M O N T H L Y   S C H E D U L E

Third-last day of the previous month

Deadline for new applicants who want to enter the competition, to pay the administration fee.

Last day of month 23:59 GMT

Deadline for submitting the predictions as an email attachment to nikke: [email protected].

1st day of the month

Previous month results are scored (actually: checked from the "winning slot", how many points are awarded to each entry - this is fully deterministic by now, and everybody already knows their score when the realized price is known at midnight or in most cases long before), published (nikke sends a compilation of results in the thread) and discussed. Actually, the points are not fully deterministic, because the initial formula supposes that all the entries are still in competition at the time of scoring. If eg. a 6-month long prediction by player A is included in the averages upon submission, but player A is disqualified from competition before the maturity of the prediction, that prediction does not take part in the counting of the final averages for the scoring, which (slightly) alters the average and, therefore, the scores of other entrants.

earliest 3rd day of the month

Nikke has averaged the new predictions and makes available the data. By downloading it and copy-pasting to the amber-colored cells in the current round, the Excel updates how many points you would be getting for this round, according to what slot the price falls into. This information does not change during the round: in the end of this prediction, one of these points values is yours - the one with the realized price.
You may post your new predictions to the thread and start discussion about them. (Don't do it before, because then we discuss the previous month's results!)

NB: The competition will start late for May, but 2014-5-31 will nevertheless be the first day to be forecasted. Special schedule applies for the start of the competition (see the beginning of the post).


E X A M P L E   O F   A   M O N T H L Y   F O R E C A S T


Forecasts will be made using a spreadsheet submission form where the slots are given, and the spreadsheet calculates that your probability totals equal 100%.

The data to be used for all of the competition is all in one sheet in the file.

In the rows, there are the slots numbered from 1-80 with their cutoff price (USD/mBTC) values.

In the columns, there are black bars that separate the 8 rounds in the game.

Each round has 3 data areas, green, amber and yellow/(changing color).

* Green area is where you make your predictions, each column corresponds to a prediction ending in a certain date, which is indicated.

* Amber area is where you can copy-paste the averages of the others' predictions, once nikke makes them available in the 3rd day of the month.

* Yellow/multicolor area is the one that shows how many points you stand to gain/lose in different price scenarios. This is an indication only, because the disqualification of other entrants before the prediction is evaluated may alter the score.

When you make the submission, we will only use the green area data from the round that is currently going on. Make sure the cells do not contain formulas and are rounded to 4 decimal places.


S C O R I N G

Each month (36 in total, because some months are forecasted multiple times in different points in time for different lengths) is scored in a similar way and their points are added to the grand total. The highest grand total after 8 rounds wins the prize.

- You get a guaranteed zero (0) points for a given round/month for submitting late, or not submitting at all, or submitting an invalid prediction. Also late entrants to the competition get 0 points for all the rounds/months they did not participate in.

- The valid predictions, get points as follows:

* Take a geometric mean of the probabilities of all the predictions at the "winning" price slot.
* If you forecasted better than the mean, you get points according to the following formula: Points = yours / average - 1
* If you forecast was worse than the mean, you get negative points as follows: Points = 1 - average / yours
* If your forecast was exactly the same as the mean, you get 0 points (both formulas also give this result)

Let's have an example with 10 predictions. After we know the realized price, it is found out that the predictors had given the following probabilities for it:

A: 5.0000%
B: 3.5000%
C: 3.0000%
D: 2.5000%
E: 2.0000%
F: 2.0000%
G: 2.0000%
H: 1.5000%
I: 1.0000%
J: 0.5000%.

Calculating the geometric mean: (0.05*0.035*0.03*0.025*0.02^3*0.015*0.01*0.005)^(1/10) = 1.9482%

Therefore the points are:

A: 5.0000% / 1.9482% - 1 = 1.5665 points
B: 3.5000% / 1.9482% - 1 = 0.7966 points
C: 3.0000% / 1.9482% - 1 = 0.5399 points
D: 2.5000% / 1.9482% - 1 = 0.2833 points
E: 2.0000% / 1.9482% - 1 = 0.0266 points
F: 2.0000% / 1.9482% - 1 = 0.0266 points
G: 2.0000% / 1.9482% - 1 = 0.0266 points
H: 1 - 1.9482% / 1.5000% = -0.2988 points
I: 1 - 1.9482% / 1.0000% = -0.9482 points
J: 1 - 1.9482% / 0.5000% = -2.8963 points

Tactical note: Although most of the predictions were awarded more than 0 points, the sum of points was slightly negative, in this case -0.0877. It is hard work to build yourself a positive points balance, but easy to lose it by giving a too small probability to an event, which is reasonably probable so that the others give it a higher probability. This not only destroys your game (should that event materialize, of course..) but also gives the others positive points, making it more difficult for you to catch up later.

A winning tactic is not only to have a solid overall understanding concerning where bitcoin price is heading, but also to avoid losses by allocating enough percentage to events that the others feel are likely to happen. Bitcoin price is determined by the market after all, and one of the grander aims of this competition is to harness the wisdom of the crowds in forecasting the price.

Some have suggested a "lucky number" tactic as a way to victory - I don't believe before I see it! (You would be rich by now on your own account...)

- If your point total goes to -20 or worse, you are disqualified from the game immediately and your possible next round prediction is forfeited. It is hardly possible to get -20 points if there is any realism in your predictions. This rule is to weed off the desperate and unrealistic "predictions" that result from people who were just gambling in the first place and the gamble went sour.


D I S T R I B U T I O N   O F   T H E   P R I Z E   P O T


All BTC in the address 1GFKAW5RunZtNEQ834wTmu4dBaYG8CRbDm at the closing of the year 2014 consists the prize pot. If there is outgoing transfers during 2014, their sum is added to the prize pot, of course.

The prize pot is distributed as follows and following order:

1. The number of entries still remaining in the game after round 8 is calculated (entries eliminated because of -20 point total don't count). 25% rounded up is taken from this number. We take entries with the best score until we reach this many. Every one of them is allocated 100mBTC from the prize pot.

2. The winner is allocated 60% of the remaining prize pot.

3. The second-best entry is allocated 1/2 of the remaining prize pot, the third-best 1/2 of the remaining and so on until we reach the last entry who was allocated 100mBTC in phase (1).

4. The remaining petty sum is added to the winner's jackpot.

5. If the winner by this calculation would receive less than 1,000mBTC, rpietila pays the balance from his own pocket.

An example of how the prize pot of 3,314mBTC is distributed if there are 23 entries in play after round 8:


1. Winner 100+1628+33 => 1761mBTC
2. Place 100+543 => 643mBTC
3. Place 100+272 => 372mBTC
4. Place 100+136 => 236mBTC
5. Place 100+68 => 168mBTC
6. Place 100+34 => 134mBTC
7.-23. Place 0 => 0mBTC


The OP is updated, but the discussion in the thread is not, so just skip the thread, it will only confuse you.