Tom Selleck is a key factor in the success of "Blue Bloods," according to co-stars Vanessa Ray and Will Estes. Selleck plays the no-nonsense patriarch, Frank Reagan, who leads the Reagan family known for their ties to law enforcement in New York City. His leadership and portrayal of Frank bring the series together, especially during family dinners where grievances are aired and personal issues are worked through. Estes and Ray acknowledge Selleck's impact both on and off-screen, crediting his experience and dedication to the show's success.