Funds run by star talent tend to see a sharp drop in outperformance if the manager exits, research by platform Willis Owen has suggested.
While the funds continued to beat their relative indices and passive products, the house noted outperfomance dropped to a ninth of its former margin, once a manager handed off to a successor.
The research examined the performance of 15 funds which waved goodbye to market-beating talent between 2013 and 2017.
Fund houses have increasingly emphasised the importance of replicable processes and continuity over the individual abilities of managers who may be lured to their rivals.
While clearly a limited sample size, the research nonetheless helps illuminate an ongoing debate about how to derive alpha.
'Star' managers considered by the study offered an average annual return over benchmark of 3.6%, versus 0.4% by their replacements.
Head of personal investments at Willis Owen Adrian Lowcock (pictured), emphasied the research did not mean fund holders should chase talent, but that manager skill was an important consideration.
He said: 'There is continual debate over the impact a manager can have on the performance of a fund.
'However, there is little doubt that a small band of star fund managers can have a huge positive impact, and our research shows what happens when they leave.
'However, in many cases the new managers who take over still out-perform their peers, but perhaps to a lesser extent. The difference in relative outperformance cannot be accounted for by the performance of the underlying market alone.'
Turning to where the house had identified consistent outperformance, Lowcock tipped some familiar names. Citywire A-rated Henry Dixon's Man GLG UK Income fund, AA-rated Nick Train's Lindsell Train Global, and A-rated Alex Darwall's Jupiter European were all among Lowcock's top picks, but he emphasised that manager ability needed to be considered in the round.
'This [research] doesn’t necessarily mean that investors should follow the manager. In many instances the manager retires, or the style happens to drop out of favour and the manager has a bad patch.
'Each situation is unique so it is important to consider all the facts before deciding what the best course of action to take is.'