Post
Topic
Board Mining
Re: The reason we do see long delays between blocks
by
bcpokey
on 14/12/2012, 11:27:30 UTC
(Nothing in this post except ultra simple math - feel free to skip it if you already know how many blocks take more than 53 minutes to be mined)


I just happened to spot this block, 53 minutes after it was created. There was no other block in site ... 53 minutes without any blocked being mined.

Wondered a bit about what the odds for this event are. So here are my (very simple) calculations, in case you were curious.

1. I dug up this old question, which reminded me Bitcoin block times followed the exponential distribution. It's basically like radioactive decay - each block has a "halflife time" of 10 minutes.
2. Realized that gamma = 10 minutes, and inputted 53 minutes into the cumulative distribution function.
3. Got 1-(e^-53/10) = 0.005

So, about 5 out of every 1,000 blocks take > 53 minutes to confirm. Nothing unusual about spotting a block like this every now and then.

A few interesting numbers:

1. The chance a block is not found within 10 minutes = 36.7%
2. Not found within 20 minutes = 13.5%
3. 30 minutes = 4.9%
4. 40 minutes = 1.8%
5. 50 minutes = 0.67%
6. An hour = 0.24%

(Divide by e = 2.718 to get the next number in line)

So it should happen roughly 10 times every difficulty period, not too unlikely.

I wonder how often this occurs though

Quote
Height   Age   Transactions
212168   52 minutes   677   25,884.30 BTC   Deepbit   260.72
212167   1 hour 34 minutes   535   10,720.04 BTC   BTC Guild   243.20
212166   1 hour 30 minutes   501   6,880.35 BTC   EclipseMC   326.54

EDIT: Fairly often I guess

Quote
212149 (Main Chain)   2012-12-14 05:39:51   00000000000002d26537d9eb939ed212171b45f2d70eccbf5b0d0939ee1e80e2   BTC Guild   189   104.49
212148 (Main Chain)   2012-12-14 05:31:39   000000000000039ca22d7de84a951c305535ec8f08449e5b059575308c266456   BTC Guild   365   226.70
212147 (Main Chain)   2012-12-14 05:33:58   00000000000002b54baa99eb63d0fd8b7e07d8d277be713257a7c23098a99b66   69.121.83.181   300   103.45

Silly timestamps.