Doctor Who: 20 Things You Didn't Know About The Ninth Doctor
7. He Was The First Doctor To Regenerate Stood Upright
As well as being the only Doctor to have his regenerations broadcast in reverse order, the Ninth Doctor was also the first Doctor to regenerate while stood in an upright position, something that became the norm from here on out.
Doctors One through Seven all regenerated while either lying down, or, in the case of the Second Doctor, while spinning around in circles and flying into an abyss. Something like that. He also regenerated while sat down in the 2024 re-edit of The War Games, so he still wasn't stood up!
The War Doctor and the Eighth Doctor did also regenerate while stood upright, but these weren't broadcast until after the Ninth Doctor's regeneration in 2005. The War Doctor's was seen in 2013's The Day of the Doctor, while Eight's was seen in the short episode The Night of the Doctor, also in 2013.
He doesn't often get credit for this, but the Ninth Doctor's regeneration kick-started a trend that saw the Tenth, Eleventh, Twelfth, and Thirteenth Doctors burst into golden flames while standing tall, making this the new norm for regenerations in the modern series.