SANTA CLARA, CALIF., JAN. 10 -- Everyone has his or her favorite theory as to why the San Francisco 49ers are so good, and how they have managed to stay that way throughout the 1980s.

Most of those theories revolve around Joe Montana and Jerry Rice, but there are others, and one in particular could be the most important to the organization if it is to stay competitive in the '90s.

San Francisco Coach George Seifert said recently he believes the league's Plan B free agency system can be used to balance what is potentially a damaging pattern. While it is obviously nice to win Super Bowl after Super Bowl, all that winning usually translates into low draft picks.

That's why Plan B has been so important to a team like the 49ers, injecting new talent into their organization that low draft picks probably won't.

The way San Francisco last used Plan B free agency -- a period that runs from Feb. 1 through April 1 and allows teams to bid on unprotected players -- is indicative of how it uses the system. While some of its six Plan B selections have either been placed on injured reserve or were cut, the rest have been major contributors to the team and have helped put the 49ers in a position to win their third straight Super Bowl.

And maybe more important, the 49ers prevented some of their most valuable merchandise, like backup quarterback Steve Young, from becoming a Plan B escapee.

Some, like Buffalo Bills General Manager Bill Polian, have criticized the way San Francisco uses the system. And it's easy to see why some league officials feel the 49ers have made a farce of Plan B, mainly designed to help the NFL's lowly teams get back on their feet.

The 49ers have a way of drastically reducing the odds of a player leaving the team. They do that by putting up big money. For example, they signed tight end Brent Jones and backup linebacker Steve Hendrickson to new contracts in the three days between the Super Bowl and the Feb. 1 deadline, and then left them unprotected.

Both Jones and Hendrickson were free under NFL rules to void their 49ers contracts and sign with other teams, but San Francisco gambled that the players' local ties would keep them in 49ers uniforms. Jones grew up in San Jose and went to San Jose State; Hendrickson was born in Richmond, Calif.

"Everything they did was totally legal," said Jones. "It was smart on their part."

"The key for them was the guys they didn't lose during Plan B," said Giants General Manager George Young, "not the guys they got."

One NFL owner, who asked not to be identified, said on Wednesday the 49ers "got the big bucks so they can take the chances. But the {Plan B} system isn't designed for the team with the big bucks. It's designed for the little guys like us that haven't won a million Super Bowls."

In April, Polian expressed similar concerns when he said, "I don't mean to say this in a critical way because the 49ers are playing by the rules, but San Francisco has subverted the system. The system is designed to hurt the strong teams. In a lot of cases it has. But not the 49ers, because they have the money and the willingness to spend it. I'm the last guy to criticize what they're doing, but the rest of us just don't have the wherewithal."

Seifert defended the signings by saying, "We're in a very competitive business. Each club goes about competing in its own style."

The money of owner Eddie DeBartolo Jr. enabled the 49ers to take chances in the last Plan B free agency. Some of San Francisco's decisions turned out to be bad ones, while other players have proven to be almost invaluable to the team.

The 49ers signed six Plan B free agents last year: cornerback Hanford Dixon, former Buffalo nose tackle Fred Smerlas, safety Dave Waymer, center Wayne Radloff, safety Greg Cox and defensive tackle John Shannon. The combined 1990 salaries and bonus payments were $2.6 million.

Now only Waymer, Cox, Smerlas, and Radloff are with the team. Smerlas is on injured reserve with a bad back, as is Radloff, out for the season because of knee surgery.

Dixon, who was told by San Francisco that he wasn't going to make it, quit the team the day before final cuts. Shannon was released.

The performance of Waymer and Cox has helped the 49ers make up for their other Plan B busts. Waymer, who came here from the New Orleans Saints, is one of the more versatile defensive backs on the team. He has played both safety positions and in their "nickel" defense has played cornerback and linebacker. He finished third on the team in tackles with 69, and proved to be invaluable when all-pro Ronnie Lott was hurt.

Cox has been one of the 49ers' best special teams players. He leads the special teams with 26 tackles.

"The difference betwen here and New Orleans," Waymer said, "is that we're in the playoffs and the Saints aren't. I think the 49ers take chances on guys like no other team in the league."

Including bonuses, Smerlas's one-year contract was for $750,000. "That was lunch money to Eddie," said Smerlas about the 49ers' owner. "The thing that makes them so good is that first, they have the money. Second, they're willing to spend it. . . . they are willing to pay for guys and they get guys with the right attitude and treat them right.

"They do everything for you, from leaving fruit baskets in our hotel room to putting us on those huge planes where we can kick back. In Buffalo, we had these teeny-weeny planes. And then, for long trips, we used to stop in Kansas City to get gas. Can you believe that? And then {Buffalo} wondered why we lost all the time."