Summary
I’ve never fully understood Paramount’s reasoning for insisting that Avery Brooks not play Commander Sisko with a bald head and beard inStar Trek: Deep Space Nineseasons 1 to 3. Captain Sisko’s bald head and beard has long been seen to signifyDS9season 4’s improvement in quality, much like when Commander William T. Riker (Jonathan Frakes) grows his beard inStar Trek: The Next Generationseason 2. Avery Brooks is more commanding with his bald head and goatee, and it’s clear that he’s a more confident member of theDeep Space Nine’s castfrom that point on.
It’s therefore perplexing that it took so long for Paramount to accept Avery Brooks' request to play the character of Sisko in such a way. AsStar Trek: Deep Space Ninewriter Robert Hewitt Wolfe puts it in the bookCaptains' Logs: The Unauthorized Complete Trek Voyages, “That’s what Avery looks like, so why shouldn’t you let the guy look like himself?” The reason given for Paramount’s ban onAvery Brooks playing Siskowith a bald head is thatthey didn’t wantDS9’s commanding officer to look like Brooks' character Hawk fromSpenser: For HireandA Man Called Hawk, but I’ve never understood why that would be a problem.

Every Star Trek: DS9 Episode Avery Brooks Directed, Ranked Worst To Best
Captain Sisko actor Avery Brooks directed nine episodes of Deep Space Nine, including one of Star Trek’s finest hours. How do his other DS9s compare?
Paramount’s Concerns About Bald Captain Sisko In Star Trek: DS9 Never Made Sense
Between 1985 and 1995, Avery Brooks played the character of Hawk in 65 episodes ofSpenser: For Hire, fourSpenserTV movies, and 18 episodes of the spinoff seriesA Man Called Hawk. By 1993, Brooks would have been well-known to audiences, which surely would have made him a draw as the lead ofStar Trek: Deep Space Nine. Which is why I’ve never understood Paramount’s ban on bald Sisko, because it disconnects Avery Brooks,DS9’s main star, from the public image that could attract new viewers toStar Trek.
Perhaps Paramount felt that the optics of Avery Brooks' Hawk as a Starfleet officer sent the wrong message and may incur the wrath ofStar Trekcreator Gene Roddenberry from beyond the grave.

Perhaps the real reason Paramount wanted Avery Brooks to shave his beard and grow out his hair was because they were uncomfortable with what Hawk represented.InSpenser: For Hire, Hawk is the best friend to the titular private detective played by Robert Urich. Despite being close friends and allies, Spenser and Hawk differ when it comes to moral scruples, with the latter working as a gangland enforcer and bodyguard. Perhaps Paramount felt that the optics of Avery Brooks' Hawk as a Starfleet officer sent the wrong message and may incur the wrath ofStar Trekcreator Gene Roddenberryfrom beyond the grave.
Directors Winrich Kolbe and Cliff Bole worked onSpenser: For Hirebefore they worked onStar Trek: Deep Space Nine.

Why Did Paramount Change Their Mind About Avery Brooks Being Bald In Star Trek: DS9?
Rick Berman and Ira Steven Behr were surprised when Paramount didn’t oppose Avery Brooks' request to shave his head forStar Trek: Deep Space Nineseason 4. Paramount’s change of mind is particularly odd becauseDS9season 4, episode 1, “The Way of the Warrior” aired in October 1995, the same year that Brooks made his last appearance as Hawk in the TV movie,Spenser: A Savage Place. Clearly, Sisko and Hawk’s similarities were no longer an issue for studio executives, but what if they never were? What if Paramount just didn’t want twoStar Trekshows with bald leads?
DS9was specifically designed to be different fromTNG, and the surface-level optics of another bald commanding officer would have underminedStar Trek: Deep Space Nine’s unique identity…

Star Trek: The Next Generation, led by bald actor Patrick Stewart, had ended 17 months before “The Way of the Warrior” was broadcast. Instead of avoiding comparisons with Spenser’s morally dubious best friend, what if Paramount were actually concerned about comparisons betweenSisko and Picard? After all,DS9was specifically designed to be different fromTNG, and the surface-level optics of another bald commanding officer would have underminedStar Trek: Deep Space Nine’s unique identity in its vitally important early years. Four years in, and despite his discomfort, Avery Brooks had more than established Benjamin Sisko as his own man.