In attempting an analysis of worst-case scenarios in MasterMind, I started working towards matching Knuth's analysis, when I realized that there seems to be a contradiction in his stated methods and his results.
Analyzing the starting move 1122, my algorithm comes up with 1134, whereas Knuth's Figure 1 B says that 2344 will be the best move to use next. Both 1134 and 2344 eliminate the same number of possibilities, so why does Knuth choose 2344, against his stated convention of taking "the first ... test pattern in numeric order" that "minimizes the maximum number of remaining possibilities"?
You can check my algorithm's output. The game so far would be:
1122 B
1344 W
And the 44-line output is (changed to match Knuth's base-1 format and sorted for convenience):
3523
3525
3526
3532
3552
3562
3623
3625
3626
3632
3652
3662
4525
4526
4552
4562
4625
4626
4652
4662
5155
5156
5165
5166
5425
5426
5452
5462
5523
5532
5623
5632
6155
6156
6165
6166
6425
6426
6452
6462
6523
6532
6623
6632
If the output isn't missing any logical possibilities, then why does he violate his own convention?