At the moment, it's heating up in Oakland and Anaheim. It could get white-hot in 2013, possibly reaching the frenzied level of the Dodgers and Giants in the Golden State.
With San Francisco entertaining visions of a third World Series title in four seasons and the Dodgers, Angels and defending American League West champion A's all brimming with talent, California is shaping up as the center of Major League Baseball's universe this season.
The reigning champions in San Francisco know they're wearing targets on their backs. They're also keenly aware of the free-spending ways of their bitter rivals down south.
The Dodgers have doubled their payroll since Opening Day 2012 to about $217 million, surpassing even the Yankees while dwarfing the Giants' estimated $140 million in salary commitments.
"They're favored over us by the experts this year," Giants manager Bruce Bochy said, acknowledging with a nod that there are worse things than the Dodgers dealing with heavy expectations. "This has been a great rivalry for a long time. It's going to be good for the game, I think.
"They've made a lot of changes, and we're the defending champions. There's a lot of interest in these teams -- and that makes for a lot of excitement. I think we're all looking forward to seeing how it plays out."
The payroll gap between the Angels (about $150 million) and A's ($61 million) is even greater than the Dodgers and Giants. The Angels and A's meet for the first time with a three-game series at Angel Stadium starting April 9.
It's rare that four clubs from the same state -- the young, down-the-road Padres are the fifth wheel -- have legitimate shots at winning it all.
"It's always exciting out here," Angels manager Mike Scioscia said. "We play good baseball year in, year out in the West. If you look at what's happened in the Bay Area and in Los Angeles, you have two really strong [California] clubs in both leagues. It epitomizes West Coast baseball."
The Dodgers and Angels have never met in October, but there have been four Golden State Fall Classics, each memorable in its own fashion.
Completing a rare World Series three-peat in 1974, the mustachioed, pitching-rich A's silenced the Dodgers in five games. Revenge was 14 years away. The '88 Dodgers took the swagger out of the Oakland "Bash Brothers" in five games.
The 1989 Bay Area showdown took a tragic turn when a massive earthquake rocked Northern California, snapping the Bay Bridge, taking down a freeway and causing a weeklong delay between Games 3 and 4 as the region tried to recover from the shock and fallout.
It was almost anticlimactic when the A's completed a sweep.
In 2002, the Giants engaged the Angels in a true Fall Classic. The Angels rallied late in Game 6 at home before seizing Game 7.
Dodgers manager Don Mattingly, a Yankees star in the 1980s, has compared Los Angeles-San Francisco to the intensity level of New York-Boston.
"I think everybody's going to want to play them," Mattingly said in reference to the defending World Series champions. "I think that's what happens with the better teams. Teams get ready for you -- day in and day out."
This will be new to the youthful A's, who shocked the two-time defending league champion Rangers by claiming the AL West. Justin Verlander and the Tigers ended Oakland's dream season.
"To be in that fifth [ALDS] game with a chance to win, there were guys in the clubhouse who will tell you we should have moved on," said Jarrod Parker, who faced Verlander in Games 1 and 5. "We won't forget about it. We were close, happy with what we did. But there's only one team that finishes the season as a champion."
The A's have to deal with a loaded division that was MLB's most competitive in 2012.
The Angels' primary rival in recent years has been Texas. Anaheim's signing of Josh Hamilton -- for years the Rangers' most lethal offensive weapon -- can only add more fuel to this feud.
Hamilton, Albert Pujols, Mike Trout and Mark Trumbo shape up as a modern murderers' row, capable of threatening the club record of 883 runs in 2009. This renewed rivalry with the A's looms as a classic puncher vs. boxer confrontation.
"They're good," Trumbo said. "They showed that last year. This division is going to be a beast.
"Oakland is always a tough place to play. There should be a lot of electricity if the crowds show up like they did late in the season when the A's took off."
After subduing the A's and moving on to the AL Championship Series, the Tigers marveled at the incredible energy generated by the Oakland fans.
"It's always exciting when you get games like that," said A's southpaw Tommy Milone, who, like Parker, was a 13-game winner as a rookie. "You feel that the stakes are higher when you get those sellout crowds and everyone's into it like the fans were last year. That's what you want. It drives you."
"When we first came here in 2000," said Scioscia, who is embarking on his 14th season as Angels skipper, "Oakland was the class of the division. We had to play at a high level to get to a division championship. It's always been there. The A's are coming off a great season, and we're looking forward to the challenge."
The Angels have restructured their pitching staff with three new starters and several bullpen imports. They signed Hamilton after Zack Greinke -- their midseason acquisition a year ago from the Brewers -- accepted the Dodgers' free-agent riches.
Fortifying their rotation was a sign of the Dodgers' respect for the Giants. It's also a firm nod toward their own history of dominant pitching, underscored this spring by the regal presence of Sandy Koufax in camp.
Along with Greinke, the Dodgers also invested in formidable Korean southpaw Hyun-Jin Ryu, enhancing a deep rotation.
The Giants' pressure-proof starters remain the gold standard. But the Dodgers could be in that class -- and their lineup is potentially lethal if Carl Crawford comes back to form and Matt Kemp recovers fully from shoulder surgery.
"You always have to look at the World [Series] champion as the team to beat," Mattingly said. "But I know we're going to feel like we're capable of doing it."
Bochy already likes the attitude and commitment of his champions. They're the team to beat, and it won't be easy.
"Success is never final," Bochy said. "You've got to do it over and over again. And we know we have our work cut out. But hopefully our motivation is to go out and make new memories."