Mining Probability Calculation and market predictions. - page 2.

Raulo

full member

Activity: 238

Merit: 100

Quote from: ranger on February 21, 2011, 02:42:26 PM

Also, I'm wondering just how lucky I was, since that's basically 3 blocks after another being generated in less than average time. If the chance of finding a block with my calculation rate in 2days were 10%, then the chance of finding 3 blocks this quickly would be less than 0.1%. Quite strange if you ask me.

You were lucky but not that lucky. The probability is described by Poisson distribution. The probability of getting at least 3 blocks when only 0.5 were expected on average is 1.4%
http://stattrek.com/Tables/Poisson.aspx

jgarzik

legendary

Activity: 1596

Merit: 1100

Quote from: ranger on February 21, 2011, 02:34:07 PM

Hi guys, I'm new here. I just started mining with HD6870 using the OpenCL miner. I'm doing about 210Mhash/sec, which according to the probability calculator (http://www.alloscomp.com/bitcoin/calculator.php) means that on average I should generate a block about every 8 days.

Instead, I have generated 3 blocks in about 4 days. This can mean two things: 1. I'm extremely lucky, or 2. the rate calculator is not quite right.

You were lucky. In 3-4 days, my 1000 Mhash/sec generated no blocks.

It's a lottery.

Over time you should see the statistical average, but right now your sample size is tiny.

ribuck

donator

Activity: 826

Merit: 1060

Quote from: ranger on February 21, 2011, 02:42:26 PM

the chance of finding 3 blocks this quickly would be less than 0.1%

If there are a thousand people generating, someone's likely to have a 0.1% experience. This was your turn. Don't worry, you're unlikely to find the next three so quickly.

N12

donator

Activity: 1610

Merit: 1010

Quote from: ranger on February 21, 2011, 02:42:26 PM

Since we're on the topic, another question: how is the difficulty level managed? Is it just coded into the clients so they know to increase the difficulty level by themselves? What if a client doesn't increase their difficulty and calculates an easy block instead? Will the network reject it?

The difficulty is determined by the network by analyzing how long it took to generate 2016 blocks. The ideal is 14 days, so if it takes shorter than this, and it usually does, the difficulty will rise accordingly.

ranger

newbie

Activity: 10

Merit: 0

Since we're on the topic, another question: how is the difficulty level managed? Is it just coded into the clients so they know to increase the difficulty level by themselves? What if a client doesn't increase their difficulty and calculates an easy block instead? Will the network reject it?

Also, I'm wondering just how lucky I was, since that's basically 3 blocks after another being generated in less than average time. If the chance of finding a block with my calculation rate in 2days were 10%, then the chance of finding 3 blocks this quickly would be less than 0.1%. Quite strange if you ask me.

ribuck

donator

Activity: 826

Merit: 1060

You were just lucky with your generated blocks. Generations are highly variable. When you have a long dry spell without a block (which you will), just look back and remember that there were good times too.

As theGECK said, the generation difficulty factor adjusts every 2016 blocks (every couple of weeks). The adjustment in 90,000 blocks will be to the payout rate, from 50 to 25 BTC per block, which is a tapering-off so that generation of new coins will eventually stop.

theGECK

sr. member

Activity: 411

Merit: 250

I seem to remember that the difficulty adjusts every 2016 blocks, not ever 90k+ blocks. The frequent adjustments of the difficulty should be enough to stop what you are saying could happen.

ranger

newbie

Activity: 10

Merit: 0

Hi guys, I'm new here. I just started mining with HD6870 using the OpenCL miner. I'm doing about 210Mhash/sec, which according to the probability calculator (http://www.alloscomp.com/bitcoin/calculator.php) means that on average I should generate a block about every 8 days.

Instead, I have generated 3 blocks in about 4 days. This can mean two things: 1. I'm extremely lucky, or 2. the rate calculator is not quite right.

This discovery has got me thinking, if Bitcoins can be generated this quickly by just a single PC, doesn't that make the bitcoin market very unstable and likely to collapse? The more people learn about bitcoins, the more will be generated. Supply will increase, the value will go down. I'm talking about the bitcoin/USD exchange rate here, which seems rather volatile. I've read a lot of posts here on the forum by people who support bitcoin with all their heart (as do I!), who are predicting the exchange rate to soar the coming year. That seems rather impossible to me, considering how fast the coins are going to be generated from now on. I realize the system balances itself by increasing the difficulty factor, but the next devaluation is still 90000 blocks away, and who knows what that will do to the market.

Any thoughts?

Topic: Mining Probability Calculation and market predictions. - page 2. (Read 17132 times)