How does the doctor choose companions

How many companions have decided to leave the doctor?

In my estimation (some are questionable) there was 20.5 voluntary, 11.5 forced, 8.5 deaths and 1 unknown (Ace). If you view death as a forced exit, roughly half of it is forced and half is voluntary (mostly out of love).

1st doctor

  • Susan wants to leave (she falls in love) but decides she can't (because she has to take care of her grandfather). The doctor is forcing her out because he knows it's best.
  • Barbara and Ian were kidnapped by the doctor. They go willingly (the doctor disagrees) if they find a way to get home.
  • Vicki falls in love and leaves voluntarily.
  • Steven volunteers to lead a peace effort.
  • Katarina dies (sacrifices herself to save the doctor).
  • Sara Kingdom (doubtful a companion) dies by accident.
  • Dodo leaves willingly (for no real reason).

5.5 voluntary exits, 0.5 compulsory exits and 2 deaths.

2nd doctor

  • Polly and Ben accidentally come to the 1st doctor. They leave voluntarily when they have the opportunity to resume their normal lives.
  • Jamie and Zoe are forced to leave by the Time Lords. (Jamie may have returned in "Season 6b," and his second departure is unknown. With the Doctor still exiled to Earth, Jamie probably had to leave.)
  • Victoria volunteers to lead a normal life (similar to Martha)

3 voluntary exits and 2 forced.

3rd doctor

  • Brigadier Lethbridge-Stewart played a role similar to a Companion, but the Doctor left him so doesn't really count for that question (and he died well after that). Same goes for Sergeant Benton and Mike Yates.
  • Liz Shaw never traveled in the TARDIS, but was essentially a companion. She left UNIT voluntarily (for no real reason).
  • Jo goes voluntarily (she falls in love).

2 optional exits.

4. Doctor

3 voluntary exits and 2 forced.

5. Doctor

  • Adric dies (save the earth).
  • Nyssa goes voluntarily, much like Steven.
  • Tegan is accidentally left behind once (but comes back to the doctor after an earth year), but finally leaves when she realizes that she can't handle the doctor.
  • Turlough voluntarily leaves (when he finds out his home planet has improved).
  • Kamelion is destroyed by the doctor when he is taken over by the master again.

3 voluntary exits and 2 deaths.

6. Doctor

1 forced exit.

7. Doctor

  • Mel is going on a different type of trip voluntarily.
  • We don't know about Ace because the series was canceled before we found out. Apparently the intention was that she went (presumably voluntarily) to be trained as a Time Lord.

1 voluntary exit, 1 unknown.

8. Doctor

  • Grace refuses to travel with the Doctor (a voluntary exit before anything even starts!), Although it is questionable whether she can be considered a companion.

0.5 voluntary outputs.

War doctor

The war doctor has no on-screen companions (I do not consider the moment a companion), although he does so in other media.

0 outputs.

9. Doctor

  • Adam Mitchell was evicted by the doctor in less than an episode.
  • Jack Harkness stays behind, though he's after Utopia returns to Torchwood voluntarily.

2 forced outputs.

10. Doctor

  • Rose has to go (although she actually stays with a doctor).
  • Mickey Smith goes voluntarily (several times!).
  • Martha goes voluntarily to lead a (somewhat) normal life.
  • Donna has to go because she can't survive the doctor's knowledge.

The 10th Doctor also had several "one-time" companions - most lists include them as companions, although they never traveled with the Doctor and only appear in a single episode. Neither of them can be considered "abandoned" by the Doctor, although two die (Astrid Peth and Adelaide Brooke), one of whom would likely have traveled with the Doctor.

2 voluntary exits, 2 forced.

11. Doctor

  • Amy and Rory involuntarily leave after a crying angel sent Rory to New York in the 1930s, and Amy willingly decides to be sent back with him. The doctor reading her tombstone creates a fixed point in time so that the doctor cannot save her.
  • River resembles a companion, although we don't really see much of her traveling with the doctor. Her last appearance in The Husbands of River Song is in "Forest of the Dead" after her official "death".

In my opinion, Craig Owens is not a companion, although he plays a similar role in one episode.

3 deaths.

12. Doctor

  • Like the Brigadier, Danny Pink never travels with the Doctor, but plays a similar role as a companion. He is killed when hit by a car, transformed into a cyberman, and eventually sacrificed to destroy the rest of the cybermen, sacrificing his return trip from the Nethersphere to send back a boy he was a soldier has killed.
  • Clara Oswald is killed and brought back between heartbeats using Time Lord technology. She fakes the Doctor into forgetting her and then voluntarily goes on an adventure with Ashildr in a stolen TARDIS. She will eventually have to return to her last moment so that she can die.
  • Bill leaves to volunteer to explore the universe with Heather (her previous cyber conversion does not appear to be death under the circumstances), though her only other choice was to return to Earth rather than continue traveling with the Doctor ( similar to) Romana).
  • Nardole is instructed by the doctor to get a group of people to safety, which he does. I consider this a forced exit.

Ashildr is similar in fellowship to Craig Owens: the Doctor is involved in several episodes with her, but she never travels with the Doctor in his TARDIS. In my opinion, she is not a companion.

1.5 deaths, 0.5 voluntary exits, 2 compulsory exits.

13. Doctor

We don't yet know how Graham, Yasmin, and Ryan will leave the doctor.

The above only includes companions who appeared in TV episodes (and in the 8th Doctoral film); those that only appear in spin-off media (audio dramas, novels, etc.) are not included. The TARDIS index file contains more information about the companions, including the fate of these additional companions.

tango

If you want to include Adelaide Brooke as a companion, you will likely need to include Lady Christina de Souza as well. Both were "unique". While Adelaide took a trip to the Tardis, it was just a one-way trip that was never meant for more. And Christina worked much more closely with him than Adelaide.

Tony Meyer

@TangoOversway I didn't list the "one-off" companions (Wilfred Mott, Jackson Lake, and Rosita Faris would also be included) - I only mentioned the two deceased, which Lady Christina didn't. I counted Astrid (as 0.5) as she was asked to become a companion, but I didn't count Adelaide (just listed her).

KutuluMike

Can you really count what happened to her at hers first appearance when spoiler happened? :) :)

Tony Meyer

@MichaelEdenfield Given that it was on end This episode occurs and is the emotional heart of much of their relationship, yes.

Paul D. Waite

The Amy and Rory entry could be updated after the seventh season.