An "underdog" is a person or group in a competition, usually in sports and creative works, who is popularly expected to lose.^[1] The party, team, or individual expected to win is called the favorite or top dog. In the case where an underdog wins, the outcome is anupset. An "underdog bet" is a bet on the underdog or outsider for which the odds are generally higher.

https://en.wikipedia.org/wiki/Underdog

MS is the underdog more than ever. However, considering the resources MS has the term underdog doesn't really fit. They just don't know how to do console business.

Don't forget Microsoft also had gears which was a beast back then and they'd timed exclusives like mass effect and Bioshock.  

Did you see europeans numbers ? Real numbers i mean, not vgchartz.

Except UK, it's a slaughter in De, Spain, France, Italy and others regions.

Still sells like shit in europe. It'll never beat xb360 sales WW if it doesnt gain ground in europe