(FORTUNE Magazine) – So who's managing your fund, anyway? If it's not a marquee name like Magellan's techie Jeff Vinik or Hans Utsch and Lawrence Auriana, co-managers of the hard-charging Kaufmann fund, that's a good question. The answer speaks not only to your fund's performance but to management's accountability in good times and bad.

At a time when mutual funds are enjoying record performances and popularity, more are managed by teams than ever before. Nearly one- third of the funds listed by Morningstar have such multiple managers, vs. just 15% in 1989. Twentieth Century, AIM, Value Line, and others say teams provide better coverage, smoother asset growth, and, for those that call on multiple advisers, diverse management styles. "No one person can do it all," insists Bob Puff, chief investment officer at Twentieth Century Funds. "Ours is the divide-and-conquer theory."

That doesn't wash with team management's detractors, who argue that fund companies use the team management status to mask manager turnover. Star managers have become a hot commodity, quietly commanding the same kind of big bucks the Wall Street wunderkinds of the ugly Eighties did. And with that kind of demand comes turnover. Says John Rekenthaler, publisher of Morningstar Mutual Funds and a big critic of teams: "Funds never have to explain away somebody's leaving if they don't tell you he or she was there in the first place."

Then there's the issue of performance. Over a recent three-year period, single and co-managed equity and hybrid funds outperformed team-managed funds by 1.2 percentage points, and teams lost in 13 out of 16 categories, including growth, small company, and international funds (one exception: aggressive growth funds). What's more, all 11 funds that consistently beat the S&P 500 on a rolling basis for the last five years were single or co-managed (see table for sampling).

Even so, some teams are worth a look. New England Funds' Star Adviser growth and income fund and the new Star Worldwide international equities fund pull together stars like Robert Sanborn of the Oakmark fund, Janus's international maven Helen Young Hayes, and Bryan Sudweeks, Montgomery's emerging-markets guru. These folks autonomously run different sectors of the same fund, competing to outdo each other. New England Funds may be onto something: Star Adviser outperformed two out of three of its peers in 1995.

--Andrea L. Prochniak