Re: [Bitcoin-development] Reworking the policy estimation code (fee estimates)

[Alex Morcos <morcos@gmail.com>]

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Oh in just a couple of blocks, it'll give you a somewhat reasonable
estimate for asking about every confirmation count other than 1, but it
could take several hours for it to have enough data points to give you a
good estimate for getting confirmed in one block (because the prevalent
feerate is not always confirmed in 1 block >80% of the time)   Essentially
what it does is just combine buckets until it has enough data points, so
after the first block it might be treating all of the txs as belonging to
the same feerate bucket, but since the answer it returns is the "median"*
fee rate for that bucket, its a reasonable answer right off the get go.

Do you think it would make sense to make that 90% number an argument to rpc
call?  For instance there could be a default (I would use 80%) but then you
could specify if you required a different certainty.  It wouldn't require
any code changes and might make it easier for people to build more
complicated logic on top of it.

*It can't actually track the median, but it identifies which of the smaller
actual buckets the median would have fallen into and returns the average
feerate for that median bucket.





On Tue, Oct 28, 2014 at 9:59 AM, Gavin Andresen <gavinandresen@gmail.com>
wrote:

> I think Alex's approach is better; I don't think we can know how much
> better until we have a functioning fee market.
>
> We don't have a functioning fee market now, because fees are hard-coded.
> So we get "pay the hard-coded fee and you'll get confirmed in one or two or
> three blocks, depending on which miners mine the next three blocks and what
> time of day it is."
>
> git HEAD code says you need a fee of 10,0000 satoshis/kb to be pretty sure
> you'll get confirmed in the next block. That looks about right with Alex's
> real-world data (if we take "90% chance" as 'pretty sure you'll get
> confirmed'):
>
> Fee rate 100000 Avg blocks to confirm 1.09 NumBlocks:% confirmed 1: 0.901
> 2: 1.0   3: 1.0
>
> My only concern with Alex's code is that it takes much longer to get
> 'primed' -- Alex, if I started with no data about fees, how long would it
> take to be able to get enough data for a reasonable estimate of "what is
> the least I can pay and still be 90% sure I get confirmed in 20 blocks" ?
> Hours? Days? Weeks?
>
> --
> --
> Gavin Andresen
>

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