Luck Versus Efficiency: VC investment decomposition

Hearing often lately about small VC fund is likely more agile and disruptive and bigger ones will lose out argument/observations, I am wondering whether there are some studies on the VC fund efficiency model. Are there something else, such as partnership dynamics, spread of the investment focuses over time, intimacy and interactive level of the due diligence process, and relationship versus valuation driven portfolio company management approach etc., playing a much larger and telling role in deciding overall success or failure of a fund or a firm? One thing is certain, some of the behavioral finance phenomena can be explained by capital/market efficiency model.

Hard to believe that VC investments are based on secretive luck. So why my luck is less lucky than someone else luck? I have noticed that firms like KPCB changed its value proposition to RELATIONSHIP. Maybe this is one of the key things that have not been paid much attention in the past?