10-15 23-18; 6-10 18-14; 9-18 24-19; 15-24 22-6; 1-10 28-19; Now 11-15 is standard, but 11-16 was given by RLF in DEO's The Square World magazine May-June 1966 pp 140-141 as arguably more restrictive. For example, 11-16 26-23; 8-11 25-22; 11-15 27-24 into standard play.
I was therefore surprised to see 11-16 being claimed as a modern computer innovation. To be fair, the literature of the game is vast and it's impossible to access it all. However, The Square World is pretty mainstream, and it's right to give RLF his due.
Incidentally, I would see the Masters' Index series as being the true forerunner of Basic Checkers, rather the 6th District Newsletter articles.
14 ballots/openings were covered in the series as follows (some by DEO, some by RLF):
1)9-13 23-18; 11-15 p180
2) 9-13 23-19; 5-9 p76
3) 9-13 23-19; 10-14 p166
4) 9-14 24-20; 11-16 p108
5) 10-15 23-18; 6-10 p140
6) 11-15 22-17; 9-13 p220
7) 11-15 23-18; 8-11 p124
11-15 23-19; 8-11 22-17; 9-13 p149) 11-15 23-19; 9-14 22-17; 5-9 p94
10) 11-15 23-19; 9-14 22-17; 7-11 p46
11) 11-15 24-20; 15-18 p280
12) 11-16 22-18; 16-19 p240
13) 11-16 24-19; 8-11 22-18 p62
14) 11-16 24-20; 16-19 p30
No doubt a booking containing 156 of these would be very popular!