Thanks for your detailed answer. I understand completely the factors and the risk that you have mentioned but I need at least to make an educated guess , so I can base my scenarios on those guesses.
I can help you with the numbers and then feel free to play with them as you see fit, I will only go back to as far as 3 years ago, as I believe values from previous years are very, very different and probably make little to no sense today (in fact even values from less year make little sense, but do hold a lot more weight than the old era when a thousand S9s would make a whole lot of difference)
Difficulty values from 15-2-2018 to 15-2-2021
2.874674234
2.967853338
3.007383866
3.2335814
3.290605989
3.381698122
3.462542391
3.494288843
3.511060553
3.796188328
3.839316899
3.943557223
4.022059196
4.138123233
4.143878475
4.219142059
4.306949574
4.415593342
4.940704886
5.024546461
5.077499035
5.172892177
5.363678461
5.199615302
5.178671069
5.595791656
5.949437372
5.949437372
6.19783992
6.389316884
6.505039002
6.72722547
6.971177231
7.019199231
7.031329606
7.152633352
7.364268059
7.454968648
7.427362643
7.182852314
7.183013626
7.184404943
7.175974755
6.653303141
6.194015746
5.646403852
5.621092246
5.106422925
5.248509607
5.618595849
5.862614532
5.883988431
5.836655169
5.814661936
5.894008795
6.061518831
6.06408179
6.07184605
6.071216044
6.068891542
6.368919654
6.379265451
6.379562392
6.393023717
6.357721118
6.353030563
6.554050172
6.702169884
6.703779555
6.704632681
6.747104133
7.459680721
7.411481914
7.409399249
7.868124125
7.93471322
8.58744535
9.064159826
9.033161131
9.013786946
9.890230142
9.985348008
10.01679887
10.18348843
10.68557238
10.77199666
10.95842971
11.89059496
12.01767456
12.7598194
12.87476027
13.00809167
13.06910849
13.69148004
13.66989171
12.72000527
12.79578964
12.97323597
12.95595155
12.87684209
12.89283761
12.94859342
13.031658
13.79878383
13.8190097
14.77636754
15.20380671
15.46609894
15.52113495
15.54674577
15.50935056
15.48691344
16.0767726
16.55292397
14.14355904
13.91252405
14.3974826
14.71521406
15.6248434
15.95865233
16.0798316
16.10480749
15.21370306
15.13804325
14.47708913
13.73235211
14.26597408
15.78474431
15.78461889
15.78421755
16.57039522
17.34594887
17.30915518
16.84756161
16.87170719
16.94780233
17.34094534
17.55799304
17.44533271
17.34599781
19.14829089
19.3146564
19.3007089
19.29808719
19.52968552
19.99733599
17.86527354
16.78777961
17.04059881
17.59680106
18.15852838
19.15715472
19.1446679
18.67016856
18.60003415
18.59959305
19.36516671
20.6074183
20.73708601
20.82353115
21.38445104
21.43439596
Percentage representation of each adjustment of the above values:
1.331956946
7.521405447
1.763511764
2.768247978
2.390641204
0.9168538
0.479974924
8.120844708
1.136101987
2.715074769
1.99063861
2.885686943
0.139078543
1.816259447
2.081169909
2.522522398
11.89220798
1.696955745
1.053877685
1.878742695
3.68819372
-3.058780657
-0.402803513
8.054587397
6.319851363
1.68098E-11
4.175227545
3.089414481
1.811181393
3.415605465
3.626335438
0.688865003
0.172817072
1.725189302
2.958836236
1.231630736
-0.370303434
-3.292020885
0.002245794
0.01936954
-0.117340091
-7.283632284
-6.903148491
-8.840983248
-0.448278349
-9.156037625
2.782509093
7.051263496
4.343054554
0.364579645
-0.804441795
-0.376812271
1.364599697
2.842039125
0.042282463
0.128036853
-0.010375847
-0.038287269
4.943705299
0.162441945
0.004654783
0.211007025
-0.552205039
-0.073777302
3.164153033
2.259972203
0.024017158
0.012726037
0.633464267
10.56122114
-0.646124261
-0.028100514
6.191121038
0.846314748
8.226285083
5.551295613
-0.341991937
-0.21447846
9.72336268
0.961735621
0.314970105
1.664100137
4.930372813
0.808794163
1.730719522
8.506376099
1.068740444
6.175444716
0.900803206
1.035602974
0.469068181
4.762157675
-0.157677097
-6.94874885
0.595788829
1.386755612
-0.133231368
-0.610603236
0.124219274
0.432455703
0.641495005
5.886632588
0.146577192
6.927832452
2.892721613
1.725174671
0.355849349
0.165006088
-0.24053396
-0.144668353
3.80875867
2.9617348
-14.55552463
-1.633499688
3.485769707
2.206854294
6.181556946
2.13639857
0.759332763
0.155324271
-5.533157905
-0.497313571
-4.366179313
-5.144245652
3.885874523
10.64610253
-0.000794557
-0.002542604
4.980783318
4.680356995
-0.212116908
-2.666759675
0.143317924
0.451022212
2.319728507
1.251648597
-0.641646922
-0.569406781
10.39025315
0.868826969
-0.072212033
-0.013583499
1.200110297
2.394562249
-10.66173242
-6.031219879
1.505971658
3.26398299
3.192212707
5.499489413
-0.065180999
-2.478493458
-0.375649598
-0.002371485
4.116077469
6.414876856
0.629228298
0.416862515
2.693682861
0.233557184
Simplified figures:
Feb 2018 to Feb 2019 :
2.8T to 6T = 114.29%
Feb 2019 to Feb 2020
6T to 15.5 = 158.33%
Feb 2020 to Feb 2021
15.5T to 21.4T = 38.06%
Keep in mind that the last year had the halving event, so the easiest thing to assume here would be doubling that increment, so it's more like 76% rather than 36%, I believe with a very high probability that the trend of difficulty will keep rising regardless of price, but will rise a lot slower than it used to.
It can't do 114% like 2018, can't do 158% like 2019, and can't do 76% like 2020, so maybe 50%? this will take us from 21.4T to maybe 32T, 50% of the current hashrate is about 80EH, each 1EH is 10,000 S19 pro, so 80EH is 800,000 S19/S19 pro, just about a million mining gears, I would be very surprised if we could go beyond that.
Thank you very very helpful information.