<p>The first rule is well understood.<br>
The second rule, ensures that difficulty gets readjusted quicker if the MTP between blocks is big (12h.)   </p>

<p>In practice:<br>
Check the MTP of the current block (mining time of a block 6 blocks earlier)<br>
compare to the MTP time of a block mind 6 blocks earlier<br>
if the difference is 12 hours then difficulty will reset<br>
for example:<br>
block 478574 has an MTP of Aug 1 14:39: UTC<br>
block 478568 has an MTP of Aug 1  11:52 UTC<br>
so not yet 12 hours apart   </p>

<p>also see: <a href="https://medium.com/@jimmysong/bitcoin-cash-difficulty-adjustments-2ec589099a8e" rel="nofollow noreferrer">https://medium.com/@jimmysong/bitcoin-cash-difficulty-adjustments-2ec589099a8e</a> (edit: fixed link)     </p>

CC BY-SA 3.0
2017-08-03T00:29:37.603Z
Not reset; drop by 20%
Pieter Wuille
CC BY-SA 3.0
2017-08-03T00:20:48.920Z
2017-08-03T03:57:23.690Z
2017-08-03T03:57:23.690Z
Albert S
<p>What were the network rules regarding the difficulty adjustments of the Bitcoin Cash chain, before the first hard fork was implemented on November 13th, 2017?
There was a rule that was a function of the time taken to find the last 2016 blocks, and one based on the Median Time of the last 11 blocks. What was the effect of these rules?</p>

<difficulty><bitcoin-cash><difficulty-retargetting>
Bitcoin Cash difficulty before first hard fork: Emergency Difficulty Adjustment (EDA)
hedgedandlevered
# Bitcoin Cash difficulty before first hard fork: Emergency Difficulty Adjustment (EDA)

(Asked by: username_0 on 2017-08-02)

What were the network rules regarding the difficulty adjustments of the Bitcoin Cash chain, before the first hard fork was implemented on November 13th, 2017?
There was a rule that was a function of the time taken to find the last 2016 blocks, and one based on the Median Time of the last 11 blocks. What was the effect of these rules?

**Tags:** difficulty, bitcoin-cash, difficulty-retargetting


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## 1 answers

### Answer by username_1 on 2017-08-03. Score: 3 | Accepted answer

The first rule is well understood.  
The second rule, ensures that difficulty gets readjusted quicker if the MTP between blocks is big (12h.)

In practice:  
Check the MTP of the current block (mining time of a block 6 blocks earlier)  
compare to the MTP time of a block mind 6 blocks earlier  
if the difference is 12 hours then difficulty will reset  
for example:  
block 478574 has an MTP of Aug 1 14:39: UTC  
block 478568 has an MTP of Aug 1 11:52 UTC  
so not yet 12 hours apart

also see: <https://medium.com/@jimmysong/bitcoin-cash-difficulty-adjustments-2ec589099a8e> (edit: fixed link)

> **Comments:**
> **username_2**: Not reset; drop by 20%  

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