Replacing a team portfolio structure with a single top manager and doing away with quantitative strategies has created a new era of accountability at Putnam Investments that appears to be having a striking effect on performance.

Putnam funds are beating 53% of their category peers for the trailing 12 months ended June 24, compared with a 21% track record the previous year. The firm’s flagship Putnam Voyager fund is up 27% year-to-date through June 24, beating the S&P 500 benchmark index by an impressive 24 percentage points and its peers by 17 percentage points.

Nick Thakore, manager of the Voyager fund, boasted a bit about his leadership, telling The Wall Street Journal, “No one should get too carried away with a few months of performance, but there’s a buzz in the investment community about Putnam now, where just a year ago it was so negative.”

Putnam also rolled out absolute-return funds and leveraged securities funds and is toying with the idea of hedge funds.

The changes are the result of the firm’s new CEO, Robert L. Reynolds, who told Putnam executives they were in for change when he took over in July 2008, saying, “We have a structure that has guaranteed us a life of mediocrity.” Reynolds fired a dozen managers and has been recruiting industry heavy hitters, particularly from Fidelity, where he had been vice chairman.