Since starting with Gridcoin in March 2018 I have noticed that the most common question we newbies have with regard to staking Gridcoins (solo mining) is: "How many Gridcoins do I need to have in my wallet to stake a block and gain my research rewards?"
The short answer is: "It depends". One of the Biggest factor is CoinWeight in your Wallet. The second biggest factor is LUCK.
The LONG answer is beautifully documented in a Blue Paper written by : James C. Owens, ILikeChocolate, Jacob T. Held
https://drive.google.com/file/d/1NwEBSKuG2IvZXPvzbTEvZLpaN2JCP_nK/view
When I first started in March all I heard was that you need ~2000 GRC to stake regularly.
With the introduction of Constant Block Rewards (mid November) I started hearing that you needed ~10000 GRC to stake regularly.
.....but wait, "What is regularly?" aaaaahhhhh, that's where luck plays into things.
I've recently been reading about people who have far greater than 10K GRC and "...haven't staked in a month"
So, with all the calculations and rules of thumbs that you will read about it mostly comes down to LUCK.
...Or at least that what it seems like for me over the last 9 months.
Below is a graph of my first 9 months staking with Gridcoin.
It shows the total GRC I have in my wallet by date with Letters indicating when I staked a block. Table shows the exact data when I staked the blocks.
Yes, I got more LUCKY with more GRC in my wallet, but I did stake with 370GRC. (diff. was low)
Q:"Is it impossible to stake today with a low balance?"
A:"No, it is just improbable"
I staked 3 times in 4 days with about 4500GRC
...well, you can see for yourself.
STAKE DATE MAG Interest Research Value Total GRC Difficulty
A 5/06/18 2.00 0.02 GRC 32.59 GRC 32.71 GRC 370.55 2.09
B 27/08/18 6.00 0.62 GRC 75.54 GRC 138.58 GRC 1,567.28 1.35
C 18/09/18 6.00 0.23 GRC 29.64 GRC 291.91 GRC 2,112.68 2.61
D 3/10/18 18.00 0.01 GRC 40.57 GRC 40.58 GRC 2,385.61 2.60
E 30/10/18 20.00 3.33 GRC 93.25 GRC 96.58 GRC 3,801.39 2.63
F 13/11/18 3.00 10.00 GRC 45.51 GRC 55.51 GRC 4,512.17 8.52
G 15/11/18 9.00 10.00 GRC 2.88 GRC 12.88 GRC 4,532.67 9.26
H 16/11/18 8.00 10.00 GRC 1.79 GRC 11.79 GRC 4,544.46 8.48
I 16/12/18 9.00 10.00 GRC 64.21 GRC 74.21 GRC 7,309.27 11.01
J 23/12/18 8.00 10.00 GRC 15.88 GRC 25.88 GRC 7,411.72 16.78
Right Now, my wallet shows Estimated Time To Stake is 15 days with a CoinWeight of 7480 and difficulty of 11.
Will it be 15 days?, or 30 days?, or Tomorrow?
I dunno, but i'm feeling lucky!