Also, this is a good moment to show you the associated difficulty graph:

Here are some keys to decode this graph:

- blue columns give the raw difficulty
- red columns give the equivalent number of required zeros for the proof-of-work
- the common difficulty is
`78`

- this common difficulty of
`78`

is equivalent to`4`

zeros

How is decided common difficulty? It is computed accordingly to the speed given by the number of blocks computed by a period of time. If the speed is too high, common difficulty increases, if too low, it decreases, otherwise it do not change.

This is a mechanism to always have the same speed of calculation for a block, on average.

You can see on this graph that the personalized difficulty of 5 of these members equals to `78`

: greyzlii, jytou, inso, moul and vincentux.

You can also see that the personalized difficulty of Gat equals to `156`

, and cgeek equals to `312`

. This is the rotation mechanism.

Considering this observations, and with the Duniter rules in mind, I can say that:

- the
*very last block*(#7446) was issued by cgeek - the
*previous block*(#7445) was issued by Gat - the other members may have issued block #7444 or whatever block before (in the limit of 100 block, so at max block #7347, protocol parameter
`blocksRot = 100`

for TestNet)

Also, I understand that if one of `[greyzlii, jytou, inso, moul, vincentux]`

succeeds to compute block #7447, then `Gat`

will come back to common difficulty `78`

, cgeek will decrease to difficulty `156`

, and the succeeding member will have difficulty `312`

.

This is how rotation works.

DIfficulty.ods (33,9 Ko)