This is part of a series of stories that comprise TheStreet's Blue Chip Studio, which will illuminate issues related to corporate board performance, activism, dealmakers and personalities revealed by analysis of data generated by BoardEx, a business unit of TheStreet.

Last month Perrigo (PRGO) - Get Report sold its royalty stream for a multiple sclerosis drug in a $2.85 billion transaction that was struck on the heels of a deal that gave activist fund Starboard Value's Jeff Smith five director seats on the company's board.

The agreement and board seat settlement was a big success for Smith - who had been urging Perrigo to conduct a strategic review for the drug, Tysabri. However, it wasn't unusual for Starboard to get board seats in the aftermath of the fund's investment in a company.

Consider that 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, 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.

Some other activist hedge fund managers may have higher profiles, such as billionaire Carl Icahn, embattled Pershing Square Capital Management's Bill Ackman or rabble-rouser Paul Singer and his fund, Elliott Management. But none have had installed as many directors onto corporate boards, particularly large companies.

According to BoardEx, 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. And in at least a couple situations, at Darden and Advance Auto Parts (AAP) - Get Report , Smith not only landed directorships for himself but he also became chairman of the board, giving him an important oversight role.

Getting dissident directors onto a corporation's board isn't by any measure a definitive sign that the activist has succeeded at its ultimate goal of driving share-price improvement for its investors. In many cases activists can pressure corporations into making share-price improving changes they are seeking - such as sell the business for a premium -- without even publicly threatening to nominate dissident board candidates, particularly if they can convince other big shareholders to support their agenda.

However, in other cases, activists win the battle but lose the war, so to speak. They succeed at getting directors onto boards but their nominees aren't helpful and the company's stock tanks nonetheless.

Nevertheless, activists that succeed at getting directors elected to corporate boards on a regular basis typically have more success at driving their share price improving agendas. Corporations, when faced with an activist with a track record of successfully getting investors to back their candidates, will often give in and add a dissident director or, more importantly, implement some of the changes, M&A or otherwise, the activist is seeking.

For example, for months, RealD Inc. postponed the deadline for shareholders to nominate director candidates as it faced the serious possibility of a Starboard director contest. The company subsequently agreed to be acquired by Rizvi Traverse Management for $551 million including debt, netting Smith's fund a premium.

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.

And while other activists haven't had the same level of success nominating director candidates, a few have had a higher percentage of their candidates set up with director positions.

Singer's Elliott Management, one of the most effective activist investors over the past decade, hasn't had to nominate dissident director candidates often in recent years to achieve results. The activist has nominated or recommended 56 candidates over the past six years, of which 38 have been installed onto corporate boards, a 67% success rate. Four additional candidates, at Arconic (ARNC) - Get Report , are still pending with a contest scheduled for May.

Billionaire Carl Icahn has drawn a lot of heat of late over concerns about conflicts relating to his investment portfolio and an advisory role he recently accepted with the Trump administration. He nominated or recommended 77 candidates over the past six years, 39 of which were installed, a 51% success rate.

Trian Fund Management's Nelson Peltz has a stellar reputation in the corporate governance community. As a result Peltz, for the most part, can get director seats for himself and others without launching a director fight. The activist has gotten ten board seats at eight portfolio companies over the past six years, with only four director candidates, at DuPont (DD) - Get Report  where Trian did launch a contest, not being elected.

And Carl Icahn protege Keith Meister of Corvex Management LP, has nominated 20 candidates of the past six years, 15 of which were installed, for a 75% success rate in board nominations.

Pershing Square's Ackman is seeking to rebound from a $4 billion loss on his Valeant Pharmaceuticals International Inc. (VRX)  investment. The fund has had more success getting directors on corporate boards, with 18 director candidates getting positions on corporate boards over the past six years through contests or recommendations. One of those positions was for himself at Valeant, as part of an ultimately unsuccessful effort to stop the drug company's downward spiral. Only six candidates didn't receive spots, but they were part of a slate up for the board of Allergan, which was acquired by Actavis in 2015, under pressure from Ackman.

Jana Partners' Barry Rosenstein, another prolific activist, has gained 27 director seats at major U.S. companies over the past six years through settlements and contests, while 11 nominees didn't get seats.

On the smaller side, activist Barington Capital, has nominated or participated in choosing 17 director candidates over the past six years, of which 12 were elected, giving the fund run by Jim Mitarotonda a 71% success rate over that period.

GAMCO Asset Management' Mario Gabelli is an activist that has been amongst the more prolific employer of boardroom battles over the years, though his fund hasn't had as much success as others getting directors installed. According to BoardEx, Gabelli has nominated or recommended 53 candidates since 2011 but was only was able to install 17 directors onto corporate boards, a 32% success rate.

At Perrigo, Starboard's Smith is likely using his board position to nudge the company towards an eventual sale of the company's prescription pharmaceutical's business. At the very least look for some sort of additional catalyst to occur at Perrigo before Smith tries to put himself on another corporate board. But don't expect Starboard to slow down its director nomination efforts any time soon.