I agree with Z, while perhaps some video game world record holders or something might be sent in to help or something, the average player would never risk their life in SAO after the first day.
Here is a recap
We join the game
Kayaba does his little bit
We form a guild known as the United Swords
The United Swords battle the Boar King mini-boss
(Here is where the timeline theoretically diverges from SAO)
First battle against the Boss fails and everyone dies, most likely because Kirito did not join in
Kirito leads the second attack on the boss
Some of the United Swords help Kirito
Midway through the fight, Kirito dies
Jag, Luke, Tyler and Ren form the main attack group
Richard bursts in with an army of BOARS
The United Swords and Jag take down the boss
Jag joins the United Swords
There it is, did I miss anything?