The stats I've compiled over the years regarding length of rotation look at how many players received 10+ minutes in "close games," defined as games after January 1 decided by fewer than 20 points. With the caveat that this may be misleading if, e.g., the 8th man in the rotation consistently receives 8 or 9 minutes, but you have to draw a line somewhere. Also, this analysis will not reveal "depth" in situations where different players receive 10+ minutes in different games (as is the case this season). For example, Jalen Johnson only played 8 minutes against NCSU, so in that game he was not considered part of the "rotation," while in other games he obviously was. In fact,
every recruited scholarship player on Duke's roster (11 players, in all) has played 10 or more minutes in at least one "close game" (as I define that).
That said, here you go, the number of "close games" (i.e., after 1/1, decided by fewer than 20 points) at which the specified number of players played 10+ minutes in each of Coach K's seasons at Duke:
Code:
Year 5 6 7 8 9 10 Avg
2021 2 6 1 1 7.10
2020 1 5 4 2 7.58
2019 1 7 9 3 6.70
2018 4 4 7 1 6.31
2017 6 14 1 6.76
2016 1 18 3 0 6.09
2015 1 9 8 2 6.55
2014 2 8 6 1 7.35
2013 6 10 2 6.78
2012 1 10 9 2 7.55
2011 6 9 5 6.95
2010 2 5 8 6 6.86
2009 1 4 10 4 1 7.00
2008 3 5 8 3 7.58
2007 1 3 11 2 6.82
2006 4 17 0 6.81
2005 6 14 0 6.70
2004 3 14 1 6.89
2003 3 17 2 1 7.04
2002 8 3 0 6.27
2001 8 8 0 6.50
2000 11 5 0 6.31
1999 2 7 2 7.00
1998 0 9 4 7.31
1997 1 9 7 1 7.44
1996 4 13 1 6.83
1995 1 8.00
1994 8 14 0 6.64
1993 7 8 4 6.84
1992 10 9 5 6.79
1991 0 13 0 4 7.47
1990 1 11 9 7.38
1989 1 9 7 7.35
1988 3 12 6 2 7.30
1987 3 11 6 1 7.24
1986 2 16 4 1 7.22
1985 10 7 2 6.58
1984 8 12 1 6.67
1983 2 6 5 1 7.36
1982 7 5 4 1 6.94
1981 7 6 3 1 6.88
As you can see, the "average" length of rotation Coach K has played this season is the 5th-most in the 21st Century (2020 tied for most, so we're playing a fair amount shorter rotation than last season). Still, using my definitions, we're still only playing a 7-man rotation (albeit with such rotation varying from game to game).
It may or may not be worth noting that of the six Duke teams in the 21st Century with an "average" > 7, only one such team (2003) has gone past the Round of 32 in the NCAA tournament, and that team (a) had the lowest average of the six teams (7.04); and (b) only made the Sweet 16.