Tinsley was promptly thrust into the starting point guard position by Pacers coach Isiah Thomas, and performed admirably for a month and a half before hitting a "rookie wall". Nevertheless, he put up admirable statistics of 9.4 points and 8.1 assists per game in 2001-02.

Tinsley played 73 games for the Pacers in 2002-03, starting 69 of them, and his averages dipped to 7.8 points and 7.5 assists per contest.

The following year, Rick Carlisle replaced Thomas as the Pacers' head coach, and immediately promoted veteran guard Kenny Anderson to the starting point guard slot, with Anthony Johnson as his backup. Tinsley was inexplicably relegated to playing backup for the backup.

But when Anderson and Johnson went down with injuries, Tinsley regained his status as a starter, and he seemed to have a newfound energy and confidence in his game-- almost as if Tinsley took his demotion as a challenge, not as a personal affront. Tinsley never relinquished his starter's role after that, and performed wonderfully as the Pacers advanced to the 2004 Eastern Conference Finals.

Tinsley spent the majority of the 2004-05 season on injured reserve (as did many Pacers), but the battered team clawed and scratched its way to a 44-38 record and the sixth seed in the Eastern Conference. Tinsley missed the first four games of the Pacers' first-round series against the Boston Celtics, but made a stunning return in Game 5 to lead his team to a crucial victory.

In two seasons, Tinsley led Iowa State to two Big 12 Conference Championships and an appearance in the Elite Eight of the 2000 NCAA Basketball Tournament. In 2001, he received Second Team All-American and Big 12 Conference Player of the Year honors.

As a teenager, Tinsley developed his game playing at New York City's legendary Rucker Park, as did such basketball icons as Wilt Chamberlain, Julius Erving, Nate Archibald, Earl Monroe, Allen Iverson, and Kobe Bryant, among others.