All the Doctors in one.

[Venardhi]

It seems reasonable that the more traumatic the death, the less control over the regeneration they would have. A Time Lord who decides they're simply getting too old and it is time to regenerate can probably put time and effort into guiding it(Casually shifting from body to body before settling on one), whereas a death by any more immediate means would be far more limiting(focus on a dress size), or uncontrollable at all (I'm a girl!?!)

 

[Stevil2001]

In Mawdryn Undead, we see technical equipment used in regeneration crises, stolen from Gallifrey, which would seem to indicate that Time Lords usually (or often) regenerate in hospital.

 

[The Borgified Corpse]

It's also quite possible that the Doctor only barely scraped by the basics in regeneration class, much as he nearly flunked out of every other class at the academy.

Interesting how the multiple "backgrounds" surrounding the composite Doctor's face in that first image resembles (to me at least) regeneration energy or a "zoom: effect for an opening credits sequence.

Has anyone seen the video clip that "blends" doctors Hartnell through Tennant into a composite. Similar concept, but animated.

http://www.youtube.com/watch?v=_BEFOe57kEY

Sincerely,

Bill

What strikes me about seeing that is how SUBTLE some of the key and defining differences in features between people are.

Yeah, those transitions are pretty damn eerie going from the subtle, almost imperceptible changes during Doctors 1-6 and 8-10. Sylvester McCoy is the only one that really doesn't look a thing like any of the others.

One thing that struck me especially was during the McGann to Eccleston transition, midway through, it looked quite a bit like how McGann looks in the more recent publicity photos he shot for the audios.