Bart

Bart, played by Jack Kelly, was the Maverick who appeared most often in that TV series.

Bret, of course, was the original Maverick, played by James Garner.

Bart and Bret were brothers. They were joined in later seasons by Beau, their cousin, played by Roger Moore.

There was a fourth Maverick, Brent, played by Robert Colbert, who appeared in a few episodes during Season 4 of the series.