Two rules met on September 22. The 45-day coinbase maturity, Knots 29.4.2, says a coin mined from block 973,440 on cannot be spent before 979,920; post fourteen has its history. Bitcoin’s difficulty retarget, unchanged on this chain, recomputes every 2,016 blocks and moves at most four times a step. This post is what our node saw of both, read at 11:06 UTC on September 23 at block 973,785.
The grace ended
A coin needs 100 blocks on top of it before any rule lets it move, so a miner on 29.4.1 could not make a block that 29.4.2 rejects until block 973,540. It came at 04:40 UTC on September 22. In the 24 hours after it our node, on 29.4.2 since September 21, rejected ten blocks: nine that day and a tenth at 04:26 UTC on September 23.
Every one failed the same check, bad-txns-premature-spend-of-coinbase: a transaction in the block spent a coin mined at 973,440 or later before it was 6,480 deep. The youngest such coin in each block was 102 to 130 blocks deep. The first four blocks each carried one offending input; the tenth carried 168, spending 62 different coinbases. Ten blocks, six coinbase tags, three of them DATUM. A DATUM tag names whose template it was, not which node built it, and a template holding one of these spends came from a node still on 29.4.1: a 29.4.2 node’s mempool does not admit them.
The same spends came back block after block. The transaction spending the coinbase of 973,443, 15e2b3f4…, is in nine of the ten. The one spending 973,445’s, 217aee27…, is in six. Old-rule mempools kept them, and every old-rule template picked them up again. One correction to our September 22 card: its depth column carried the coin the node’s log named, the first premature input it met; in five of the nine rows that was 217aee27…’s, 118 to 221 deep. The table above has the youngest coin in each block.
Nobody built on any of them. Each is a branch of length one in getchaintips, and the chain moved on from the block before it every time. No coin from the window has moved: 10,749 coinbase outputs from 973,440 to 973,785, none spent.
The spent share
Our ledger reads every coinbase since activation and asks the node whether each output is spent. Per UTC day, the share of that day’s mined XBT already spent was 65 to 93 percent for every day from September 9 to September 20. September 21, the day the rule took effect at 17:49 UTC, reads 12.5 percent: the coins mined before that hour. September 22 reads 0.0 percent, and so does September 23 so far.
The old 100-block wait alone would leave a day’s last hours unspent, not the whole day. The earlier bars keep climbing as their coins are spent.
The sixth retarget
Block 973,728 came at 02:28:40 UTC on September 23. The window behind it, 971,712 to 973,727, ran 893,732 seconds over 2,015 intervals, 443 seconds a block, about 33.1 PH/s at the old difficulty. Difficulty went from 3,417,233,412 to 4,625,039,957, a 1.353x step, the second the cap did not touch; the fifth, on September 12, was 2.99x, and the three before it were 4x each. Since the step the chain has run 57 blocks at 545 seconds a block, about 36.4 PH/s at the new difficulty. At that pace the seventh retarget, at 975,744, lands about October 5 at about 1.1x. The front page carries all six.
The two rules together
Post fourteen named the problem: hash that arrives for a profit window, sells every coin the day it can, and leaves. The one-part fix measured the window: 26,112 XBT above bitcoin’s schedule between August 30 and September 17, paid because difficulty moved at most four times a step while hashrate arrived thirty times faster. The maturity rule takes the dash out of hash-and-dash. The retarget’s lag is down to a window that ran 35 percent above schedule, 443 seconds a block against 600. September 22 was the first full day under the maturity rule, and what the node recorded is the shape of it: old-rule templates carrying spends the new rule refuses, ten blocks nobody followed, and a day’s coins that stayed where they were mined.
We ran one node. Every number above is from it. If something here is wrong, say so on X and this post gets fixed and dated.
Saved you an hour? Tip the node and the clankers.