You really believe they would risk getting orphaned by ski= pping the longer chain, just to attempt to reduce average block size? No, t= hat doesn't happen today. Laziness in leaving the default size is common. B= ut that is not collusion, nor an attempt to manipulate the block sizes of o= ther miners.
>

On 24 Jun 2015 10:05 am, Mark Friedenbach <= mark@friedenbach.org> wrote:

They do so by not building on larger blocks
>
On Jun 23, 2015 9:31 PM, "Raystonn" &l= t;raystonn@hotmail.com&= gt; wrote:
No, they can lower their own block= sizes.?? But they cannot currently lower the sizes of blocks mined by othe= rs.?? That is not the same thing by any stretch of the imagination.
>
On 23 Jun 2015 8:50 pm, Jeff Garzik <jgarzik@gmail.com> wrote:
Miners can collude today to lower the block si= ze limit.

In fact, this largely happens already out of= laziness - miners often follow the "soft" default limit set by Bit= coin Core, to the point where you can chart when miners upgrade to new soft= ware:??http://hashingit.com/analysis/39-the-myth-of-the-megabyte-b= itcoin-block

On Tue, Jun 23, 2015 at 8:05 PM, William Madden <will.madden@novauri.com> wrote:
Here are refutations of the approach in = BIP-100 here:
> http://gtf.org/garzik/bitcoin/BIP100-blocksizechangeproposal.pdf >
> To recap BIP-100:
>
> 1) Hard form to remove static 1MB block size limit
> 2) Add new floating block size limit set to 1MB
> 3) Historical 32MB message limit remains
> 4) Hard form on testnet 9/1/2015
> 5) Hard form on main 1/11/2016
> 6) 1MB limit changed via one-way lock in upgrade with a 12,000 block
> threshold by 90% of blocks
> 7) Limit increase or decrease may not exceed 2x in any one step
> 8) Miners vote by encoding 'BV'+BlockSizeRequestValue into co= inbase
> scriptSig, e.g. "/BV8000000/" to vote for 8M.
> 9) Votes are evaluated by dropping bottom 20% and top 20%, and then the > most common floor (minimum) is chosen.
>
> 8MB limits doubling just under every 2 years makes a static value grow > in a predictable manner.
>
> BIP-100 makes a static value grow (or more importantly potentially
> shrink) in an unpredictable manner based on voting mechanics that are
> untested in this capacity in the bitcoin network.?? Introducing a highly<= br /> > variable and untested dynamic into an already complex system is
> unnecessarily risky.
>
> For example, the largely arbitrary voting rules listed in 9 above can be<= br /> > gamed.?? If I control pools or have affiliates involved in pools that
> mine slightly more than 20% of blocks, I could wait until block sizes
> are 10MB, and then suddenly vote "/BV5000000/" for 20% of blocks = and
> "/BV5000001/" for the remaining 10%.?? If others don't consis= tently vote
> for the same "/BV#/" value, vote too consistently and have their = value
> thrown out as the top 20%, I could win the resize to half capacity
> "/BV5000001/" because it was the lowest repeated value not in the= bottom
> 20%.
>
> I could use this to force an exodus to my sidechain/alt coin, or to
> choke out the bitcoin network.?? A first improvement would be to only let=
> BIP-100 raise the cap and not lower it, but if I can think of a
> vulnerability off the top of my head, there will be others on the other > side of the equation that have not been thought of.?? Why bother
> introducing a rube goldberg machine like voting when a simple 8mb cap
> with predictable growth gets the job done, potentially permanently?
>

>
> On 6/23/2015 9:43 PM, odinn wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > 1) Hard fork not (necessarily) needed
> > 2) See Garzik's BIP 100, better (this is not meant to say "s= uperior to
> > your stuff," but rather simply to say, "Better you should wo= rk with
> > Garzik to implement BIP-100, that would be good")
> > 3) See points 1 and 2 above
> > 4) If still reading... changes should be (as you seem to have been > > trying to lean towards)... lean towards gradual change; hence, chang= es
> > that would flow from this BIP would be better off oriented in a
> > process that dies not require the "way you have done it." > >
> > You did address that, to be fair - in your TODO, this link:
> > http://gavinandresen.ninja/time-to-roll-out-bigger-blocks
> >
> > contained the following link:
> >
> > htt= p://gavinandresen.ninja/bigger-blocks-another-way
> >
> > However, in reading that, I didn't see any meaningful statements= that
> > would refute the approach in Garzik's BIP-100.
> >
> > Maybe a better way to say this is,
> >
> > Work with Jeff Garzik (which I am sure you are already having such > > discussions in private) as well as the list discussions,
> > Move forward on BIP-100 with Garzik and other developers (not such a=
> > bad plan really) and don't get caught up in XT.?? (If you feel y= ou can
> > develop XT further, that is your thing but it would perhaps make you=
> > lose focus, work together with other developers.)
> >
> > Relax into the process.?? Things will be ok.
> >
> > Respectfully,
> >
> > - -O
> >
> > On 06/22/2015 11:18 AM, Gavin Andresen wrote:
> >> I promised to write a BIP after I'd implemented
> >> increase-the-maximum-block-size code, so here it is. It also liv= es
> >> at:
> >> https://github.com/gavinandresen/bips/blob/blocksize/bip= -8MB.mediawiki
> >>
> >>?? I don't expect any proposal to please everybody; there are=
> >> unavoidable tradeoffs to increasing the maximum block size. I > >> prioritize implementation simplicity -- it is hard to write
> >> consensus-critical code, so simpler is better.
> >>
> >>
> >>
> >>
> >> BIP: ?? Title: Increase Maximum Block Size Author: Gavin Andrese= n
> >> <gavinandresen= @gmail.com <mailto:gavinandresen@gmail.com>> Status:
> >> Draft Type: Standards Track Created: 2015-06-22
> >>
> >> ==Abstract==
> >>
> >> This BIP proposes replacing the fixed one megabyte maximum block=
> >> size with a maximum size that grows over time at a predictable > >> rate.
> >>
> >> ==Motivation==
> >>
> >> Transaction volume on the Bitcoin network has been growing, and<= br /> > >> will soon reach the one-megabyte-every-ten-minutes limit imposed= by
> >> the one megabyte maximum block size. Increasing the maximum size=
> >> reduces the impact of that limit on Bitcoin adoption and growth.=
> >>
> >> ==Specification==
> >>
> >> After deployment on the network (see the Deployment section for<= br /> > >> details), the maximum allowed size of a block on the main networ= k
> >> shall be calculated based on the timestamp in the block header.<= br /> > >>
> >> The maximum size shall be 8,000,000 bytes at a timestamp of
> >> 2016-01-11 00:00:00 UTC (timestamp 1452470400), and shall double=
> >> every 63,072,000 seconds (two years, ignoring leap years), until=
> >> 2036-01-06 00:00:00 UTC (timestamp 2083190400). The maximum size= of
> >> blocks in between doublings will increase linearly based on the<= br /> > >> block's timestamp. The maximum size of blocks after 2036-01-= 06
> >> 00:00:00 UTC shall be 8,192,000,000 bytes.
> >>
> >> Expressed in pseudo-code, using integer math:
> >>
> >> function max_block_size(block_timestamp):
> >>
> >> time_start = 1452470400 time_double = 60*60*24*365*2 siz= e_start =
> >> 8000000 if block_timestamp >= time_start+time_double*= 10 return
> >> size_start * 2^10
> >>
> >> // Piecewise-linear-between-doublings growth: time_delta = > >> block_timestamp - t_start doublings = time_delta / time_doub= le
> >> remainder = time_delta % time_double interpolate = (size= _start *
> >> 2^doublings * remainder) / time_double max_size = size_start= *
> >> 2^doublings + interpolate
> >>
> >> return max_size
> >>
> >> ==Deployment==
> >>
> >> Deployment shall be controlled by hash-power supermajority vote<= br /> > >> (similar to the technique used in BIP34), but the earliest possi= ble
> >> activation time is 2016-01-11 00:00:00 UTC.
> >>
> >> Activation is achieved when 750 of 1,000 consecutive blocks in t= he
> >> best chain have a version number with bits 3 and 14 set (0x20000= 004
> >> in hex). The activation time will be the timestamp of the 750= 9;th
> >> block plus a two week (1,209,600 second) grace period to give an= y
> >> remaining miners or services time to upgrade to support larger > >> blocks. If a supermajority is achieved more than two weeks befor= e
> >> 2016-01-11 00:00:00 UTC, the activation time will be 2016-01-11<= br /> > >> 00:00:00 UTC.
> >>
> >> Block version numbers are used only for activation; once activat= ion
> >> is achieved, the maximum block size shall be as described in the=
> >> specification section, regardless of the version number of the > >> block.
> >>
> >>
> >> ==Rationale==
> >>
> >> The initial size of 8,000,000 bytes was chosen after testing the=
> >> current reference implementation code with larger block sizes an= d
> >> receiving feedback from miners stuck behind bandwidth-constraine= d
> >> networks (in particular, Chinese miners behind the Great Firewal= l
> >> of China).
> >>
> >> The doubling interval was chosen based on long-term growth trend= s
> >> for CPU power, storage, and Internet bandwidth. The 20-year limi= t
> >> was chosen because exponential growth cannot continue forever. > >>
> >> Calculations are based on timestamps and not blockchain height > >> because a timestamp is part of every block's header. This al= lows
> >> implementations to know a block's maximum size after they ha= ve
> >> downloaded it's header, but before downloading any transacti= ons.
> >>
> >> The deployment plan is taken from Jeff Garzik's proposed BIP= 100
> >> block size increase, and is designed to give miners, merchants,<= br /> > >> and full-node-running-end-users sufficient time to upgrade to > >> software that supports bigger blocks. A 75% supermajority was > >> chosen so that one large mining pool does not have effective vet= o
> >> power over a blocksize increase. The version number scheme is > >> designed to be compatible with Pieter's Wuille's propose= d "Version
> >> bits" BIP.
> >>
> >> TODO: summarize objections/arguments from
> >> http://gavinandresen.ninja/time-to-roll-out-bigger-blocks.
> >>
> >> TODO: describe other proposals and their advantages/disadvantage= s
> >> over this proposal.
> >>
> >>
> >> ==Compatibility==
> >>
> >> This is a hard-forking change to the Bitcoin protocol; anybody > >> running code that fully validates blocks must upgrade before the=
> >> activation time or they will risk rejecting a chain containing > >> larger-than-one-megabyte blocks.
> >>
> >> Simplified Payment Verification software is not affected, unless=
> >> it makes assumptions about the maximum depth of a transaction= 9;s
> >> merkle branch based on the minimum size of a transaction and the=
> >> maximum block size.
> >>
> >> ==Implementation==
> >>
> >> https://github.com/gavinandresen/bitcoinxt/tree/blocksize_fork
> >>
> >>
> >>
> >> _______________________________________________ bitcoin-dev mail= ing
> >> list bitcoin-dev@lists.linuxfoundation.org
> >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
> >>
> >
> > - --
> > http://abis.io ~
> > "a protocol concept to enable decentralization
> > and expansion of a giving economy, and a new social good"
> > https://keybase.io/odinn > > -----BEGIN PGP SIGNATURE-----
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> > -----END PGP SIGNATURE-----
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> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > >
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