<p>I admit that I don't know for sure, but I have a guess.  Since Satoshi was mining by himself for the first blocks, he probably set the initial target to whatever would take approximately 10 minutes to mine a block on his CPU.  Had he set it to the maximum value for a 256 bit number, he would have mined the first 2,016 blocks almost instantly, and then immediately retargeted.</p>

<p>Because of the large number of blocks mined in such a short amount of time, this would likely have caused the retargeting calculation to produce a less-than-perfect result, meaning that the <em>next</em> 2016 blocks may be mined either far too quickly or far too slowly.</p>

<p>It was probably just better for him to initialize the target to a reasonable value, rather than force the algorithm to run its course in order to produce one.</p>

CC BY-SA 3.0
2017-01-18T17:22:19.120Z
The difficulty can only go up or down by a factor of four each time, so it would take 16 re-targets to get to difficulty 1. That would create a pre-mine of 1.6 million Bitcoins. (16*2016*50)
Nick ODell
CC BY-SA 3.0
2017-01-18T19:18:20.350Z
Yikes!  I was just thinking about how long it would take before stabilizing at a 10 minute block time.  I forgot about how many coins would be mined during that process.
Jestin
CC BY-SA 3.0
2017-01-18T20:10:03.157Z
Of course, it would have been possible to set the *initial* target different from the *maximum* target, to allow for the possibility for the target to go up or down from the initial value.  However, if the initial target was a reasonable number for one person's computer(s), there would probably be no point in allowing it to go higher, since that should never happen.
Nate Eldredge
CC BY-SA 3.0
2017-01-18T15:10:11.440Z
2017-01-18T15:10:11.440Z
Jestin
<p>Is there any specific reason why the initial target was set to this:</p>

<pre><code>00000000ffff0000000000000000000000000000000000000000000000000000
</code></pre>

<p>Why not the maximum value for a 256 bit number:</p>

<pre><code>ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
</code></pre>

<mining-theory><difficulty><satoshi-nakamoto>
Why was the maximum target set to 0xffff0000000...?
inersha
# Why was the maximum target set to 0xffff0000000...?

(Asked by: username_0 on 2017-01-18)

Is there any specific reason why the initial target was set to this:

```
00000000ffff0000000000000000000000000000000000000000000000000000

```

Why not the maximum value for a 256 bit number:

```
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

```

**Tags:** mining-theory, difficulty, satoshi-nakamoto


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## 1 answers

### Answer by username_1 on 2017-01-18. Score: 8 | Accepted answer

I admit that I don't know for sure, but I have a guess. Since Satoshi was mining by himself for the first blocks, he probably set the initial target to whatever would take approximately 10 minutes to mine a block on his CPU. Had he set it to the maximum value for a 256 bit number, he would have mined the first 2,016 blocks almost instantly, and then immediately retargeted.

Because of the large number of blocks mined in such a short amount of time, this would likely have caused the retargeting calculation to produce a less-than-perfect result, meaning that the *next* 2016 blocks may be mined either far too quickly or far too slowly.

It was probably just better for him to initialize the target to a reasonable value, rather than force the algorithm to run its course in order to produce one.

> **Comments:**
> **username_2**: The difficulty can only go up or down by a factor of four each time, so it would take 16 re-targets to get to difficulty 1. That would create a pre-mine of 1.6 million Bitcoins. (16*2016*50)  
> **username_1**: Yikes!  I was just thinking about how long it would take before stabilizing at a 10 minute block time.  I forgot about how many coins would be mined during that process.  
> **username_3**: Of course, it would have been possible to set the *initial* target different from the *maximum* target, to allow for the possibility for the target to go up or down from the initial value.  However, if the initial target was a reasonable number for one person's computer(s), there would probably be no point in allowing it to go higher, since that should never happen.  

---

