Do you know what metod is bitcoincharts.com using to estimate next difficulty? Is it sliding window of 2016 blocks?
I'm watching
allchains.info. Author says he is using the exact calcluation since last diff change. Right now there is 1652 blocks left in this round (18.06% blocks measured), with 9.43% increase. Bitcoincharts: 4.38%.
use linear extrapolation method, you can easily do all these calculations by yourself:
1) go to
http://blockexplorer.com/q/nethash/2016, take latest block number (currently: 243936). This is first block after difficulty change.
A = 2439362) go to
http://blockexplorer.com/b/243936 (or insert new block number from step 1 in case of difficulty change), click on "Raw block" link, copy value from field "time" (in this case: 1372515725). This
B = 13725157253) now take block number from step 1, add to it any value between 1 and 2015. In this case it will be 126, or 252, or 378, etc..
C = 243936 + 126 = 2440624) go to
http://blockexplorer.com/b/244062, click on link "Raw block", copy value from field "time" (1372584672)
D = 1372584672Result formula:
(60*60*24*14)/((D-B)/(C-A)*2016)-1
Result is 0.096494409, that is ~9.65%
I don't know about
http://bitcoincharts.com/ algorithm, unfortunately it is impossible for me to find missing values there. Anyway, with allchains approach difficulty increase estimation every 126 block is following:
126 (1/16): 9.65%
252 (2/16): 9.98%
378 (3/16): 10.04%
504 (4/16): 9.65%