Only two NBA/pro basketball dynasties in my opinion:
1) The George Mikan and Minneapolis Lakers dynasty which won six pro championships in seven years as the Minneapolis Lakers - 4 in the NBA and two in the NBA's predecessor pro basketball league) with only a one year where the Minneapolis Lakers were not the pro basketball champs in a seven year period.
2) The Bill Russell and Boston Celtics dynasty of 11 NBA titles in 12 NBA Finals over a 13 year period where only one year where the Boston Celtics were not in the NBA Finals in a 13 year period while winning 11 out of 12 NBA Finals championships in a 13 year period including EIGHT straight NBA titles and never going more than a year without a NBA title. Now that is a dynasty.
Only the Minneapolis Lakers and the Boston Celtics have won consistent NBA titles as neither team went more than one year between NBA titles.
As far as Duncan:
1) 1999 NBA ring
2) 2000 chance at 2000 NBA ring on a great team, but Duncan blew out a knee at the very end of the 2000 season
3) 2001 Duncan's knee held out until deep until the 2001 playoffs when the knee gave out on him as he continued to play but couldn't jump deep into the 2001 playoffs
4) 2002 Duncan's knee held out until deep until the 2002 playofffs when the knee gave out on him as he continued to play but couldn't jump deep into the 2002 playoffs
5) 2003 NBA ring
6) 2004 Duncan's knee held out until deep until the 2003 playoffs when the knee gave out on him as he continued to play but couldn't jump deep into the 2004 playoffs after three straight years of playing basketball without a layoff (2003 NBA Spurs championship, 2003 NBA Spurs World Team championship in Italy, playing on the USA Olympic Team during the pre-qualifying and the Olympics, so for 2002, 2003, and 2004 Tim Duncan played nothing but basketball without a rest
7) 2005 NBA ring
8) 2006 lost in seven games to the Western Conference finals after the playoff schedule forced the Spurs to play two entire NBA playoff games including Game One in the Western Conference Finals and fly half way across the country in less than 38 hours and played Game Two in the Western Conference Finals resulting in three NBA playoff games being played in less than an 86 hour period which NBA Commissioner David Stern apologized for saying Conference Finals scheduling like this requiring that a team, in this case be required to fly across the country and play 3 NBA playoff games all in a matter of less than 86 hours). This 2006 playoff schedule gave Dallas an unfair advantage in the 2006 Western Conference Finals as Dallas only had to play two games within a 48 hour period and no cross country flights during this same period where the Spurs, in my opinion, had the better team, but were just worn out between the beating Sacramento in California before returning to Texas and playing Game One of the Western Confernce Finals all in less than 38 hours.
9) 2007 in 2007 NBA Finals
Tim Duncan had he not had the knee injury and the 2006 Western Confernce playoff scheduling problem for which NBA Commissioner David Stern has apologized for could very well have been in nine consecutive NBA Finals had the 2000 major knee injury at the very end of the 2000 NBA regular season allowed Duncan's knee not be fully recover in 2000, 2001, and 2002.
Tim Duncan's nine years at playing at the top is a good run but due to injury technically would not call this a dynasty of the Spurs dominance of the NBA for nine years from 1999 to 2007 in the Tim Duncan era of the Spurs dominance of the NBA.
But to me dynasties are like the George Mikan Dynasty and Minneapolis Lakers dynasty (6 titles in seven years) or the Bill Russell Dynasty and the Boston Celtics dynasty (11 titles and 12 NBA Finals in thirteen years).
For Duncan and the Spurs, they have dominated the NBA for nine years and the Lakers three peat would have never happened had Duncan not had major knee surgery just days before the 2000 NBA playoffs and had Duncan's knee held out the entire 100 or 110 game plus exhibition season, regular season, and playoffs as Duncan's knee gave out deep into the Western Conference playoffs in both 2001 and 2002.
So, the Lakers three peat was somewhat handed to them as they did not have to play the injured Duncan in 2000 and in 2001 and 2002 Duncan's knee which was great during the regular season, gave out deep into the playoffs of those years, so, the Lakers three peat should have an asterisk as the 2000, 2001, 2002 Lakers either played against an out for the playoffs Duncan or a one legged Duncan.
Still, Duncan one one leg is better than the other PFs in the league but could not carry an entire team on his shoulders.
The Lakers, in my opinion, only had a three peat because of Duncan's late season 2000 major knee surgery.
But, no I do not consider the Spurs a dynasty during the Duncan era; however, the Spurs have had the best record percentage wide of any of the four major North American sports in the Duncan era if that qualifies for a dynasty which it does not with me. It just means that Duncan and the Spurs from 1997 to 2007 have just had the best ten year win loss record in major North American sports.
I think Duncan would be satisfied with that as major knee injuries do occur and you cannot play the "what if" game.