I suppose I have to make a confession. I'm occasionally at risk of having a nerdy streak. Take this topic and all this talk about randoms and probabilities and chances of this or that. I just could not help myself and I ended up implementing 4d6 drop lowest character rolling in an Excel sheet. It doesn't use real random, it only uses Excel pseudo-random, but since we're not doing high tier data science I reckon that it is good enough.
And it turns out that on merely my 694th attempt, I rolled a freaking 100!! I got cought up in the moment and rolled a nice 10,000 characters. And while that was hugely fun, I must rather shamefully admit that actually digging through the stats and finding "good fits" was not quite as fun, so top and bottom selections are based on sum total of stats rather than a detailed assessment of fitness for purpose.
To avoid any risk of selection bias becoming a problem, let's start with the first 50 characters that I rolled. Rows with exception stats (16 or more) are indicated with a star. I picked 16 because with the right race bonus, this can mean a starting 18 and thus a faster time to naked 20. Perhaps small thing but that is the purpose of this whole excercise, isn't it? Note that only three of these gentlepeople managed a natural 18. These are indicated with a triple-star.
Index STR DEX CON INT WIS CHA Sum All Dice
1 18 10 12 15 15 14 84 6636 4241 2641 5462 6425 5363 ***
2 14 11 12 12 11 15 75 4461 1623 3451 4216 3424 3616
3 12 7 10 13 8 9 59 1615 1214 1316 1265 2511 3323
4 10 13 11 15 10 17 76 1514 6522 3441 2654 4333 6565 *
5 12 9 12 15 12 16 76 3145 4141 3154 5553 1543 5265 *
6 14 12 14 14 11 14 79 3156 2336 6135 6352 2236 4364
7 16 11 15 14 17 14 87 6545 2415 5446 5541 4665 6262 *
8 14 14 14 5 16 14 77 3516 4346 3625 2211 5635 4554 *
9 14 14 12 15 15 13 83 4554 4515 2641 1663 1546 4345
10 12 16 17 11 6 9 71 4442 6515 5566 2452 1231 2333 *
11 10 6 13 13 10 11 63 2621 2113 2553 1346 3243 1434
12 14 9 12 10 12 13 70 5631 2423 3542 3251 1156 5253
13 11 11 15 14 15 8 74 2541 2434 5446 1635 4356 4221
14 6 11 16 12 8 7 60 2122 5313 4565 1264 4113 5111 *
15 13 13 10 15 10 15 76 5135 2463 1613 1645 1154 6632
16 12 11 16 14 11 13 77 5252 6322 6255 3563 3612 2544 *
17 9 16 12 12 15 13 77 3214 5615 4352 4414 5535 5253 *
18 10 13 14 6 13 9 65 1451 4245 4552 2131 2165 1423
19 9 9 10 12 13 12 65 3233 3115 2235 6241 5621 5522
20 15 8 12 7 15 10 67 6435 4122 6242 3131 1564 2612
21 13 9 8 12 8 17 67 2561 1351 1215 3415 4222 5664 *
22 16 14 11 12 13 10 76 6264 4634 3235 2642 4361 3423 *
23 11 13 18 11 13 11 77 4116 1445 6636 5333 6243 5233 ***
24 10 7 12 15 10 11 65 3161 3131 4126 6336 2244 1254
25 14 14 13 12 10 11 74 3265 6353 3426 4216 4332 5412
26 13 15 16 8 12 18 82 5153 2564 6641 1215 1543 6666 ***
27 13 10 4 10 13 8 58 6243 5232 2111 3432 6134 4212
28 16 11 11 11 9 9 67 5625 3351 1362 3162 3242 2611 *
29 15 13 15 13 9 14 79 1645 4245 6543 4254 5131 3615
30 15 10 11 15 13 12 76 6361 2216 2353 5624 4245 1165
31 11 7 12 15 9 11 65 1344 2123 3326 1546 3332 2541
32 16 15 14 15 14 8 82 5651 5436 5326 4546 5361 1125 *
33 16 12 11 15 9 14 77 4662 1363 4134 3465 2333 4552 *
34 12 8 12 10 9 17 68 6313 4221 2146 5123 2342 6615 *
35 12 13 14 12 12 15 78 3541 2265 4614 6124 4622 5146
36 13 9 14 16 13 14 79 4263 1414 4436 4266 4542 6352 *
37 15 10 13 11 10 9 68 3663 5321 4632 5421 4224 1153
38 16 14 15 12 12 14 83 1565 6226 4654 3524 2552 3625 *
39 13 14 16 12 13 7 75 6234 2365 6555 6242 6521 4211 *
40 13 9 10 12 9 13 66 4354 1225 5223 2264 2152 4452
41 13 8 10 9 9 15 64 4514 1242 1163 2143 1126 3456
42 13 6 7 12 10 12 60 4544 1141 2114 4622 5223 2164
43 11 14 14 7 13 9 68 1623 6532 5514 2123 6116 1162
44 12 12 13 13 14 8 72 4531 6124 3355 4613 2446 2142
45 12 10 15 6 12 12 67 1156 6212 4645 2311 5334 1516
46 13 11 13 13 14 7 71 6161 6312 4136 5621 4155 4211
47 13 13 12 13 11 12 74 6423 3535 4315 1643 4423 4135
48 12 6 13 15 10 14 70 5413 4111 6215 5416 2235 6442
49 11 7 12 12 6 12 60 3434 2321 4444 5125 1312 2363
50 11 9 14 10 9 13 66 4152 1153 4644 4224 4322 2445
As can be seen, there really are quite a lot of these people that are not particularly cut out for the life as an adventurer. Without any way to switch values for stats or trade points between them, the regular rolling isn't necessarily producing great option. However, if one isn't the impatient sort who stops at a mere 50 people in order to find one's true self for a particular playthrough, it is also possible to roll overall superior life forms like the following.
Index STR DEX CON INT WIS CHA Sum All Dice
694 17 17 16 17 17 16 100 5566 1566 5561 6465 5665 5645
1793 18 17 17 15 16 15 98 6466 6655 5661 5464 4661 3456
9397 17 17 13 16 18 16 97 6653 6456 5513 5465 6666 6525
6298 18 15 16 14 16 17 96 6664 5364 3655 3644 6255 3566
6823 17 16 17 16 14 15 95 5656 5365 6465 5625 3455 2456
1801 14 15 14 16 18 17 94 4614 1465 4553 5562 6166 5664
5207 18 14 16 17 11 18 94 6616 6226 4266 4665 1452 6616
6988 12 16 18 17 14 17 94 1264 6364 6466 6565 3561 5566
7261 14 15 16 16 17 16 94 3653 5246 6355 4466 2656 6614
7679 18 17 14 17 15 13 94 6466 6653 3615 5616 6154 5325
7926 16 18 17 16 12 15 94 4466 4666 6562 4663 3354 3616
81 10 16 15 17 17 18 93 4214 6346 6361 5626 6561 5666
303 17 15 16 13 15 17 93 6165 1663 6641 5531 4562 6256
1957 14 15 17 15 16 16 93 1464 6451 2656 6163 5265 6164
2895 17 16 16 13 15 16 93 5665 6624 6552 2561 4265 1466
4031 18 17 14 17 10 17 93 6626 6556 6315 6625 3432 6615
4732 15 17 13 14 16 18 93 5416 6265 4514 3464 1664 3666
5944 16 16 18 14 15 14 93 4661 6355 1666 3365 6326 6414
6009 15 17 17 13 13 18 93 6425 6356 6564 1436 6324 6266
8057 14 17 15 14 16 17 93 4515 6256 6524 3455 2664 6564
8259 18 17 16 9 18 15 93 6616 6635 6614 2512 6636 6541
9878 14 16 16 18 14 15 93 5623 5615 5652 6616 3265 5643
And of course there also ended up being a whole bunch of people that would serve a good role in life as target practice for horrid wiltings, fodder for the gel cubes, stuffing for a flesh golem, or raw material for a mad necromancer's zombie horde.
Index STR DEX CON INT WIS CHA Sum All Dice
4456 7 8 7 5 10 6 43 2132 3411 3131 2121 4133 1231
2021 7 10 6 12 6 8 49 1223 4412 3112 5423 2222 1116
141 4 6 11 6 10 13 50 1211 1114 2263 1123 3314 3642
1067 7 9 10 6 8 10 50 2223 1342 2343 2222 3114 5141
1094 8 10 6 9 11 6 50 2233 3251 4111 3422 2353 1321
1162 7 10 10 6 9 8 50 2312 2126 4224 1213 1612 3232
2589 5 11 9 8 12 6 51 3111 4225 3241 1413 2246 1222
2918 8 10 10 8 8 7 51 5121 1442 2424 2421 1332 1214
3982 10 11 6 9 10 5 51 3134 5133 4111 1153 1424 3111
6898 5 7 7 11 11 10 51 1221 3122 1331 1551 3126 1244
7528 11 11 9 7 4 9 51 4611 3144 5113 2114 2111 3331
8330 10 9 6 9 6 11 51 1361 3124 1312 2215 1123 4252
8683 8 8 9 5 11 10 51 1116 2313 1441 3111 3523 3341
9612 6 11 8 7 11 8 51 1411 4225 3322 1322 5214 2115
2706 5 7 14 11 5 10 52 2121 4211 3562 4512 1113 1613
6633 11 4 10 11 10 6 52 5511 2111 1253 3533 4422 1231
6913 12 12 9 5 6 8 52 2444 2426 4322 1122 2212 2115
7597 7 13 7 8 10 7 52 2223 1364 3311 2313 3433 1313
9539 10 4 12 13 5 8 52 5321 2111 2534 6611 1311 1431
144 5 10 7 12 12 7 53 1221 3152 2312 2264 5343 1331
569 7 10 10 11 11 4 53 2114 4323 1613 4611 4243 2111
4300 6 9 6 13 14 5 53 2113 3323 3211 2364 3545 1122
4367 5 10 15 7 8 8 53 1221 2424 3166 4121 2332 2242
7904 12 13 5 5 6 12 53 3361 2544 2112 2121 1114 1561
283 5 7 10 14 14 4 54 1221 1133 1352 6144 5316 1211
585 8 10 6 12 12 6 54 1134 3611 3211 4443 5521 1114
2905 7 9 11 8 10 9 54 3131 1324 2136 2224 3512 4213
3248 10 8 7 10 9 10 54 3432 4122 2123 1253 3511 3116
7854 11 8 8 9 6 12 54 1641 5121 2412 2423 3211 3452
8401 12 9 5 8 12 8 54 4523 2252 1212 2133 1354 3321
8731 11 7 7 15 8 6 54 3352 2231 3311 5644 2422 1321
8833 9 8 4 15 10 8 54 4321 2242 2111 4645 3521 1152
8867 12 11 5 11 7 8 54 4235 2344 1221 3315 3212 4131
9797 13 7 9 10 8 7 54 5444 1313 5311 2126 3411 1142
9919 7 6 15 8 8 10 54 1232 2221 6345 3114 3223 3611
I think this very clearly demonstrates the volatility of 4d6 drop lowest and why Larian hasn't implemented it yet. If they do, they will probably take the BG1 and 2 route of letting players trade points between their stats after the roll, and it is conceivable that instead of actually rolling multiple d6, they'll just roll a single random between 3 and 18, making extreme values much more likely.
