Many players have worn both the red and gold and the silver and black. Here are some of the best. Can you spot them?
With the San Francisco 49ers facing the Oakland Raiders on Sunday for the first time since 2010, the time is right to review the best players to play for both teams.
Cornerbacks Carlos Rogers and Tarell Brown, who switched sides this season, were just the latest examples of players crossing the bay.
(Rogers was placed on Injured Reserve last week, but the 49ers will see Brown as part of Week 14 action.)
1. Quarterback: Jim Plunkett
San Francisco: 1976-77 | 62.5 passer rating
Oakland/Los Angeles: 1979-86 | 75.7 passer rating
Other QBs: Jeff Garcia and Rick Mirer.
2. Linebacker: Matt Millen
Oakland/Los Angeles: 1980-88 | 127 starts
San Francisco: 1989-90 | 25 starts
LBs:Bill Romanowski and Riki Ellison.
3. Safety: Ronnie Lott
San Francisco:1981-90 | 51 interceptions
Los Angeles: 1991-92 | 9 interceptions
S: Rod Woodson.
4. Running back: Roger Craig
San Francisco: 1983-90 | 7,064 rushing yards
Los Angeles: 1991 | 590 rushing yards
Take a look back at the memorable career of the 49ers Hall of Fame running back who played eight seasons for San Francisco.
5. Wide receiver: Jerry Rice
San Francisco: 1985-2000 | 1,281 catches (176 touchdowns)
Oakland: 2001-2004 | 243 catches (18 touchdowns)
WRs: Randy Moss and Ashley Lelie.
6. Fullback: Tom Rathman
San Francisco:1986-93 | 294 catches
Los Angeles: 1994 | 26 catches
Take a look at the two-time Super Bowl fullback's 22-year playing and coaching career with the San Francisco 49ers.
7. Offensive linemen: Jeremy Newberry
San Francisco: 1999-2005 | 86 starts
Oakland: 2007 | 14 starts
OL:Ron Stone, Kevin Gogan and Barry Sims.
8. Defensive line: Andre Carter
San Francisco: 2001-05 | 32 sacks
Oakland: 2012 | 2.5 sacks
DL:Dana Stubblefield, Ted Washington, Archie Reese and Cedrick Hardman.
9. Cornerback:Nnamdi Asomugha
Oakland:2003-10 | 11 interceptions
San Francisco: 2013
CBs: Shawntae Spencer, Rogers and Brown.
Who are we leaving out?
Tight ends Jamie Williams and Ted Kwalick; defensive back Dave Waymer...