I'm on board with Billie Piper playing Ncuti Gatwa regenerating into Billie Piper. Exactly what Piper's role will be moving forward remains to be seen, as, tellingly, Doctor Who did not credit her character as "the Doctor," suggesting some Bad Wolf-ish shenanigans could be afoot.

Nevertheless, Piper has emerged from the golden glow of a dying Fifteenth Doctor, and that makes her, until such time as Doctor Who confirms otherwise, the Sixteenth. To say that Doctor Who's latest lead actor represents a huge risk would be an understatement of planet-sized proportions. Beyond the canon ramifications - which are huge, obviously - a big question mark hangs over whether such a daring choice will backfire massively. With Doctor Who season 16 not yet confirmed, it might not matter, but assuming the TARDIS does vworp back onto screens, Billie Piper's Doctor must adhere to one rule.

Billie Piper's Sixteenth Doctor Should Be Another Transitional Doctor, Like David Tennant's Fourteenth

It's The Only Way Billie Piper's Sixteenth Doctor Can Work

In returning to Doctor Who's showrunner position, Russell T Davies introduced the concept of a transitional Doctor - an innovation that, broadly speaking, worked quite well. David Tennant assumed the role of the protagonist's fourteenth official incarnation to guide the franchise through its 60th anniversary and provide a familiar face during uncertain times. With a knowing whiff of nostalgia, Doctor Who sought to reacquaint itself with lapsed fans and provide a gentle bridge into a brand-new era. The questionable addition of bi-generation aside, "The Star Beast," "Wild Blue Yonder," and "The Giggle" marked a return to form following the heavily-criticized Flux season.

Hiring a completely new actor as the Doctor when Doctor Who's status remains so murky would be nonsensical.

Billie Piper's role as the Sixteenth Doctor should be exactly what Tennant's was as the Fourteenth. Once again, Doctor Who finds itself in a phase of great change, and the prospect of a lengthy hiatus is entirely feasible. Over the next few years, Doctor Who may be limited to occasional special episodes, should the BBC continue production without the involvement of Disney or another third party. In that situation, the presence of Billie Piper would make total sense, just as the presence of Tennant did during the 60th anniversary specials.

Piper's Sixteenth Doctor might appear a few times a year, especially when bells begin ringing around December. She would feature in a select few adventures that resolve the lingering questions of Doctor Who season 15, including Susan's cameo, the Boss, and why the Doctor turned into a Rose Tyler lookalike. Then, when Doctor Who is inevitably restored to its full-time status, Piper can the baton to a totally new actor to drag Doctor Who into the future.

Hiring a completely new actor as the Doctor when Doctor Who's status remains so murky would be nonsensical, especially if that new actor was a young up-and-comer who may not be able to make a firm commitment to the show. As a longstanding member of the Doctor Who family and an established RTD favorite, Billie Piper is a much safer pair of hands.

The Main Problem With Billie Piper As A Full-Time Doctor

The Thorny Side To Rose's Return

If, however, Doctor Who's plan is to install Billie Piper as a permanent Doctor throughout Doctor Who season 16 and beyond, I would take issue with that. The problem isn't Piper herself - an undeniably great actor widely loved for her role as Rose Tyler - but the familiarity she brings.

Billie Piper is not the first leading Doctor Who actor to appear in the show as another character before landing the top job. Colin Baker portrayed Gallifrey's Commander Maxil before donning his infamous technicolor dreamcoat, while Peter Capaldi played one-off characters in both Doctor Who and Torchwood. But Doctor Who has never, Tennant aside, brought back a main cast member as the Doctor, and between 2005 and 2006 (then again in 2008), Piper certainly was a main cast member.

Sixteen's excited expression and opening line of "oh, hello" feel exactly like Rose Tyler.

There is, after all, a reason the Fourteenth Doctor only lasted three episodes before regenerating settling down in Chiswick. Doctor Who is all about progression, change, and a revolving door of leading Time Lords and Ladies. Sticking with Tennant permanently would have represented a backward step - a transparent attempt at emulating former glories. Billie Piper may have played a companion, but exactly the same issue arises. Being promoted one step up the TARDIS hierarchy is not enough to overcome the fact that multiple seasons of Piper's Sixteenth Doctor would feel like treading over old ground.

And therein lies the other issue: it would be old ground. A few seconds of screen time and a single line is, of course, nowhere near enough to ascertain a true picture of the next Doctor's personality. Nevertheless, Sixteen's excited expression and opening salvo of "oh, hello" feel exactly like Rose Tyler. The same was true of the Fourteenth Doctor. Tennant had the opportunity to play a completely unique version of the Time Lord, but Fourteen ended up as a very deliberate continuation of Ten. Early indications suggest Sixteen and Rose will follow that trend.

If Billie Piper's Sixteenth Doctor turns out to be a gloomy, anti-social, awkward incarnation in the mold of the First, Sixth, or Twelfth Doctors - or even something entirely unique like the Shalka Doctor - I will happily sit back and watch a full season of Doctor Who with her at the helm. If Sixteen turns out to be as much like Rose Tyler on the inside as she does on the outside, however, there is surely only so much mileage in her being the new face of Doctor Who.

Doctor Who Feels Like It's Repeating Itself

Doctor Who Has Gone A Bit Timey-Wimey

Billie Piper's return to Doctor Who continues a recent pattern of revisiting the same narrative ideas. That's the case irrespective of how long the Sixteenth Doctor sticks around, but will turn into a more glaring problem if Piper has indeed been recruited as a full-time Doctor.

The reveal of Billie Piper is unavoidably close to when Jodie Whittaker regenerated into David Tennant.

Looking at Doctor Who season 15 alone, the Rani's return felt a lot like the Master's comeback in season 3. Both were secret Time Lord villains hiding in plain sight, who then regenerated as soon as they revealed themselves and created dystopian versions of Earth that the Doctor would eventually reverse. Omega, meanwhile, felt very similar to Sutekh in of being a monstrous CGI villain summoned from the classic era with a few choice retcons.

The reveal of Billie Piper is unavoidably comparable to when Jodie Whittaker regenerated into David Tennant, with the departing Doctor's replacement being kept a closely-guarded secret, only to be unveiled as a familiar figure from RTD's original era. After Tennant and now Piper, it feels like reality could shift one degree to the left and the Doctor would suddenly be Camille Coduri.

One might argue that Piper serving as a transitional Doctor would make Sixteen and Fourteen even more alike, and that assertion would be absolutely correct. At the same time, repeating the trick for a few specials over the next couple of years is infinitely preferable to three or four whole Doctor Who seasons with Rose Tyler as the Doctor.