Do VCs Impact the Outcome with Value-Add Post Investment?

Last night, I witnessed a fascinating debate between two venture capitalists. At question is the issue of whether vc-value add (ie operating best practices, sales acceleration, etc) impacts the probability and size of the ultimate success.

In one corner, we had a former operator who argued that value add is indeed both possible and necessary. In the other, a career investor who made the argument that venture is an exercise in picking, ie asset selection trumps post-close asset management.

The latter argument went something like this..."a typical investor has ten board seats once scaled. With 50% of time spent prospecting, that leaves 50% to focus on existing portfolio. 50% translates into ten working days per month or one day per portfolio company. If my one day per month truly helps the team, then that the team is weak and my help is unlikely to matter."

The former..."as a former operator, I have seen the movie many times. If my prior experience can help companies avoid mistakes or accelerate execution via my operating best practice skills, then it will help drive outcomes and deltas from unaided supervision."

What is your experience? Are venture capitalists "asset pickers" or "asset managers," where is the value created? Selecting the right companies or moulding companies to be right?