Hi, I discussed this issue in the following thread
Summary of what I wrote there :
My pool had 130-219k ADA staked from epoch 364 until 381 then 1.68M ADA from epoch 382.
Between epoch 367 and 382 included no block were assigned. There was a 1.1% probability for that to happen.
Since then my pool had 5 blocks assigned in epoch 384 and 392. With the current stake, there was a 2% chance for that to be happening for each epoch so my pool has been extremely “lucky”.
Today I calculated the leadership schedule for epoch 398 and… No block assigned… That’s the fourth consecutive epoch without block assigned, there is a 0,3% chance for my pool to have four consecutive epochs without any block assigned…
The current lifetime luck for my pool is 99.6% so I suppose I can’t complain.
I am almost sure that my pool is configured correctly, in my opinion Cardano’s block assignment is not random, it follows some kind of pattern or is influenced by some factors which is a big issue for small pools and causes a lot of stress to their operators.
Edit : this post provides some information about the block assignment probability Slot leader schedule & historical assignments