Activist fund Starboard Value's Jeff Smith has nominated - and installed -- more dissident director candidates onto corporate boards over the past six years than any other activist hedge fund manager in that time frame.

That's according to a review of the top activists and their director-election records, employing data provided by relationship mapping company BoardEx, a unit of TheStreet. With director positions, Starboard has been able to effect a wide-variety of share-price improving actions at companies, involving M&A, stock buy backs or operational changes.

To put the director-battle environment in a broader context, TheStreet took a look at the top activists and their director-election records over the past six years, employing data from BoardEx. Like Smith, most of the most successful activists have had a record of getting dozens of their candidates elected onto boards.

Overall, according to BoardEx, the top 15 activist funds, as chosen by The Deal, nominated or recommended 588 director candidates at U.S. companies since 2011 - and of those 330 were installed onto corporate boards through director-election contests or negotiated settlements, about a 56% success rate.

Specifically, Starboard Value nominated 153 director candidates over the past six years. Of those, 86 were installed - about 56% of nominees -- at a wide variety of corporations including well-known targets such as Yahoo! (YHOO) , Darden Restaurants (DRI) - Get Report , Office Depot (ODP) - Get Report and Brink's (BCO) - Get Report . Some came in contests that went the distance, such as at Darden, the owner of the Olive Garden restaurant chain, but others like at Perrigo, came in settlements