algorithms – Can’t wrap my head around on building a suffix table for Boyer Moore

My resources were the following video, as well as this video.

Basically, in one of the videos they state that the good suffix table for the pattern “ABCBAB” is the following:

k suffix d2
1 B 2
2 AB 4
3 BAB 4
4 CBAB 4
5 BCBAB 4

and for “DRIDI”:

k suffix d2
1 I 2
2 DI 5
3 IDI 5
4 RIDI 5

If all of the above is correct, I can’t understand why in the first table, for k = 5, we have d2 = 4 (because we match the A with the suffix “BCBAB”?), where as in the second table for k = 4, we cannot do the same (match D with the D inside the suffix “RIDI”), hence why the value for d2 is the length of the pattern, i.e 5 and not 3.

What’s going on here?