Forget for a moment who deserves to be crowned the bond king. For the past year and more, Jeffrey Gundlach has beaten the pants off Bill Gross.

Of course, there are some caveats. Big ones. For one, Gross oversees $245.5 billion in assets at PIMCO's Total Return Fund, while Gundlach manages a much smaller $8.7 billion at the DoubleLine Total Return Bond Fund.

It's whale versus minnow, but in a world where minnows can succeed. Gundlach can flit in and out of positions far more rapidly because of his portfolio's size, and his holding of more exotic securities could have a greater impact on performance -- albeit on the downside, too.

The two managers are something of rivals in the fixed-income world. Court testimony from a consultant who worked with Gundlach said the bond manager told him PIMCO wanted him as Gross's eventual replacement.

The bond mavens have vied for the bond king title for some time. For investors who have wrestled with how to play the market, who's been the better bet, Gross or Gundlach?

Gross has earned the title with his long track record - PIMCO's Total Return fund

has racked up average annual returns of 7.42 percent in the last 10 years, outpacing the Barclays Capital U.S. Aggregate Index's 5.68 percent annual gain, according to PIMCO.

Morningstar named Gross Fixed Income Manager of the Decade in 2010, an award in which Gundlach was a finalist.

Gundlach has earned the title more recently by leaning heavily on mortgage-backed securities for performance, investments considered to be riskier than Gross's more diversified portfolio. The DoubleLine fund held almost 30 percent of below investment grade debt in July.

This year Barron's called Gundlach the new bond king, citing data over the past decade. Long-term comparisons are difficult because Gundlach left the Trust Company of the West in late 2009 to set up his own firm, DoubleLine Capital LP.

BEATING BENCHMARKS

Since the inception of DoubleLine's Total Return Bond fund in April 2010, institution class shares have returned 17.7 percent through last Thursday, compared to 6.5 percent for PIMCO Total Return, according to Lipper Inc, a unit of Thomson Reuters.

While the rest of the fixed income world was hesitant to extend duration this spring, DoubleLine was aggressive in buying deeply discounted agency CMOs tied to the 10-year Treasury, said David Schawel, portfolio manager at Square 1 Bank who owns the DoubleLine fund in his own account.

As the yield curve flattened, DoubleLine was perfectly positioned while other firms shunned securities exposed to this part of the curve.

Year to date, DoubleLine is up 7.65 percent, versus 3.19 percent for PIMCO. The benchmark Barclays Capital U.S. Aggregate Index is up 5.61 percent since 2011 began.

The two funds are very different, so it's an apples to oranges comparison. Bond managers who have examined Gundlach's fund are at a loss to explain his outsized returns.

I don't know what (Gundlach's) magic formula is, but obviously he's got one, one bond portfolio manager said. The thing that impresses me is when Treasuries are down, he's up. When Treasuries are up, he's up.

Eventually everybody's going to find out (what he's doing) and the returns are not going to be there. Or either that he's just a genius, the manager said.

(Reporting by Herbert Lash; Editing by David Gaffen and Walden Siew)

Vs