Bill Chisholm’s private equity firm, STG Partners, was “one of the smallest players in a bidding war” to acquire cybersecurity company RSA Security from Dell Technologies five years ago, but now the “same traits appear to have driven Chisholm to an even more audacious acquisition:” his purchase of the Celtics, according to Chavez & Welker of the BOSTON BUSINESS JOURNAL. RSA CEO Rohit Ghai “was impressed with Chisholm’s tenacity” as a negotiator and his ability to “‘punch above his weight’ against much larger competitors.” In the past few decades, Ghai said that Chisholm “has excelled at private equity” through “his ‘innate sense for timing and risk.’” He cited Chisholm’s “discipline and ability to align his team and get them to rally behind the business methodology.” Chavez & Welker noted Chisholm has “been a Celtics fan since growing up watching the powerhouse Celtics teams of the 1970s and ’80s.” The future owner “was joined in his bid” by private equity firm Sixth Street Partners, along with two Boston-area businessmen: Granite Telecommunications co-founder and President Rob Hale and Related Cos President Bruce Beal Jr. The two minority owners in Chisholm’s ownership team have “also called themselves devout fans.” While Chisholm is “a virtual unknown” as a major sports team owner, that is “not unusual.” Patriots owner Robert Kraft and Red Sox owner John Henry, both of whom now “own two of the richest sports groups in the world, were likewise unknown when they became owners” (BOSTON BUSINESS JOURNAL, 7/23).