Many accelerators and investors have a basic position that bore out in the research undertaken in 'the startup genome report'.
'..the findings confirm what are commonly held beliefs, such as the drawbacks of being a single person founder. Solo founders take 3.6 times as long to reach scale stage as do founding teams of 2 and they are 2.3 times less likely to pivot.' http://readwrite.com/2011/05/28/the-startup-genome-project-e...