<p>Obviously the choice was somewhat arbitrary as well as largely unexplained. This is true of several other constants chosen by Satoshi Nakamoto.</p>
<p>According to <a href="https://bitcoin.stackexchange.com/q/92974/13866">What is the length of largest known reorganization in bitcoin?</a></p>
<blockquote>
<p>the value overflow incident in August 2010 [...] caused a re-org of 53 blocks</p>
</blockquote>
<p>So having the maturity be 100 blocks rather than 50, or less, may have some benefit every now and again?.</p>

CC BY-SA 4.0
2021-10-11T10:34:19.487Z
Thanks for your reply, I wish I could accept all the answers.
liorko
CC BY-SA 4.0
2021-10-10T17:30:14.577Z
2021-10-10T17:30:14.577Z
RedGrittyBrick
<p>It is 100, because that's what Bitcoin's creator set it to. It's part of the system's consensus rules now, and cannot easily be changed. It also doesn't really hurt.</p>
<p>In retrospect, it is likely too high. The purpose of the maturity is making sure that when a deep reorganization takes places, no transactions that directly or indirectly spend coinbase outputs exist, as those will be invalidated. Given the fact that reorganizations that are more than a few blocks are extremely rare, 100 is likely overkill. Then again, it's a good thing the value is higher than what is ever needed, and again, it doesn't really hurt anyone.</p>
<blockquote>
<p>What happen if I will decrease my coinbase maturity to 50? It will affect different parameters of the bitcoin network (block creation time, target timespan, targer spacing, etc.)?</p>
</blockquote>
<p>The network will simply reject your transaction, or at the very least the transaction will not confirm until the coinbase outputs it is spending are 100 old.</p>
<p>The Bitcoin Core wallet used to actually enforce a coinbase maturity of 120 before permitting spending. Note that this was a local wallet policy, distinct from the consensus rule that requires 100. This policy was removed, as 100 turned out to be more than enough.</p>

CC BY-SA 4.0
2021-10-10T14:22:37.483Z
2021-10-10T14:22:37.483Z
Pieter Wuille
<p>I understand the logic behind coinbase maturity.
One thing that I cannot find an answer for is why it's defined 100 and not 50?
Is it just probability reason to decrease that orphan blocks will be created?</p>
<p>What happen if I will decrease my coinbase maturity to 50? It will affect different parameters of the bitcoin network (block creation time, target timespan, targer spacing, etc.)?</p>

<consensus><immature-coins>
Why coinbase maturity is defined to be 100 and not 50?
liorko
# Why coinbase maturity is defined to be 100 and not 50?

(Asked by: username_0 on 2021-10-10)

I understand the logic behind coinbase maturity.
One thing that I cannot find an answer for is why it's defined 100 and not 50?
Is it just probability reason to decrease that orphan blocks will be created?

What happen if I will decrease my coinbase maturity to 50? It will affect different parameters of the bitcoin network (block creation time, target timespan, targer spacing, etc.)?

**Tags:** consensus, immature-coins


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## 2 answers

### Answer by username_2 on 2021-10-10. Score: 10 | Accepted answer

It is 100, because that's what Bitcoin's creator set it to. It's part of the system's consensus rules now, and cannot easily be changed. It also doesn't really hurt.

In retrospect, it is likely too high. The purpose of the maturity is making sure that when a deep reorganization takes places, no transactions that directly or indirectly spend coinbase outputs exist, as those will be invalidated. Given the fact that reorganizations that are more than a few blocks are extremely rare, 100 is likely overkill. Then again, it's a good thing the value is higher than what is ever needed, and again, it doesn't really hurt anyone.

> What happen if I will decrease my coinbase maturity to 50? It will affect different parameters of the bitcoin network (block creation time, target timespan, targer spacing, etc.)?

The network will simply reject your transaction, or at the very least the transaction will not confirm until the coinbase outputs it is spending are 100 old.

The Bitcoin Core wallet used to actually enforce a coinbase maturity of 120 before permitting spending. Note that this was a local wallet policy, distinct from the consensus rule that requires 100. This policy was removed, as 100 turned out to be more than enough.


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### Answer by username_1 on 2021-10-10. Score: 7

Obviously the choice was somewhat arbitrary as well as largely unexplained. This is true of several other constants chosen by Satoshi Nakamoto.

According to [What is the length of largest known reorganization in bitcoin?](https://bitcoin.stackexchange.com/q/92974/13866)

> the value overflow incident in August 2010 [...] caused a re-org of 53 blocks

So having the maturity be 100 blocks rather than 50, or less, may have some benefit every now and again?.

> **Comments:**
> **username_0**: Thanks for your reply, I wish I could accept all the answers.  

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