N.L.C.S.: Past Two World Series Champions Duel for a Chance to Return The League Championship Series has been part of baseball since 1969, but never before has it featured a matchup like this: the last two World Series champions going head-to-head for the pennant. That is how it stands in the National League. The San Francisco Giants won the title in 2010. The St. Louis Cardinals followed in 2011. Both won their rings by beating the Texas Rangers. Now, one team must top the other for the right to return to the stage, where the Rangers will not be waiting. The Rangers bowed to Baltimore in the American League wild-card game. The Cardinals played in the N.L. version, surviving against the Atlanta Braves, and then mounted their latest breathless comeback to beat the Washington Nationals in Game 5 of their division series Friday. The Giants clinched their division series the day before by winning a third consecutive road game in Cincinnati. Comeback victories. Success on the road. Both teams will be fearless as they enter the N.L.C.S., which starts Sunday. In Game 1, the Giants left-hander Madison Bumgarner will face the Cardinals' Lance Lynn, who was last seen allowing the homer to Jayson Werth that ended Game 4 in Washington. Yet make no mistake: Lynn is not an accidental starter. He made the All-Star team in July, and although he went winless in August, he finished with victories in his last four starts. Over all, Lynn was 18-7 with a 3.78 earned run average in the regular season, and he had more strikeouts than innings. Bumgarner, just 23, is already a Giants mainstay, with a six-year contract extension and eight shutout innings in the 2010 World Series on his résumé. Bumgarner was 16-11 with a 3.37 E.R.A. this season before losing his start in the division series. That was in Game 2, when the Giants looked finished, having lost the first two games by a combined score of 14-2. But the Giants' offense stirred to life at Great American Ballpark in Cincinnati, supporting decent starting pitching and a typically stingy bullpen that Manager Bruce Bochy expertly deploys. Mike Matheny, the Cardinals' rookie manager, has a similarly wide array of weapons to use from the bullpen, including the second-half additions Edward Mujica and Trevor Rosenthal. The Nationals' Bryce Harper detected a pattern last week: admiringly, he said, "Every pitcher out of their pen throws 100." ALL OR NOTHING Chris Carpenter, the Cardinals' likely starter for Game 2, has had a fascinating decade with St. Louis. In 4 of the last 10 seasons (2003, 2007, 2008 and 2012), he pitched so little that he won no games in the regular season. In each of the other six seasons, he was above .500, winning the Cy Young Award in 2005, the E.R.A. title in 2009 and World Series championships in 2006 and 2011. He is 10-2 with a 2.88 E.R.A. in 16 career postseason starts. The Giants and the Cardinals met just six times this year, and they played only two games at AT&T Park in San Francisco. The teams split the games, and half of the Giants' 30 total runs came Aug. 8 in a 15-0 rout at Busch Stadium. Cardinals starter Joe Kelly, who lost that night, is in the bullpen for this series. GLOVE STORY The Cardinals reserve Matt Carpenter does not wear batting gloves, which is unusual but not as rare as the style the Giants' Hunter Pence prefers. Paul Lukas, the sports style expert at Uni-Watch.com, wrote in June that Pence was the only active major leaguer who wore just one batting glove. POSEY TAKES OVER The Giants went 30-15 after the All-Star Melky Cabrera was suspended in August for failing a drug test. Catcher Buster Posey led the way, hitting .348 with a .973 on-base plus slugging percentage over that stretch and becoming a strong candidate for the N.L. Most Valuable Player award. Eight of the last 12 N.L. winners have come from the Cardinals or the Giants. Cabrera, incidentally, was eligible to return after the Giants' fifth playoff game, but the team has no plans to bring him back. MOTTE'S MECHANICS With Giants closer Brian Wilson out after elbow surgery, the bushiest beard for a closer this series belongs to the Cardinals' Jason Motte, edging the Giants' trimmed-down Sergio Romo. More interesting than Motte's hair, though, is his quirky habit of pumping the ball in his glove as he delivers a pitch. "It just kind of happened," Motte, a converted catcher, explained in March. I don't know if maybe it's part of what I did when I caught. It's just my timing to get my arm up, get everything up where it needs to be. I'm sort of a short, quick, boom-boom kind of guy. POSTSEASON HISTORY The teams have met twice in the N.L.C.S., most recently in 2002, when the Giants won on a series-ending single by Kenny Lofton in Game 5. The more compelling series was in 1987, when the Giants went to St. Louis for Game 6 needing one victory for their first pennant in 25 years. They never scored again, getting shut out by John Tudor and two relievers in Game 6 and by Danny Cox in Game 7. Even so, the Giants' Jeffrey Leonard - who wore No. 00 and whose "one flap down" home-run trot incensed the Cardinals' pitchers - became the last player from a losing team to win a postseason M.V.P. award. COMMON ALUMNI The patron saint of this series is Frankie Frisch, a fleet second baseman who helped each team to two championships in a Hall of Fame career that stretched from 1919 through 1937. Frisch played 1,000 games for the Giants before being traded to St. Louis for another Hall of Fame second baseman, Rogers Hornsby, after the 1926 season. Some 40 years later, the Giants sent another player bound for Cooperstown, Orlando Cepeda, to St. Louis, for pitcher Ray Sadecki. Cepeda, who had won the Rookie of the Year award for the Giants, helped the Cardinals to a title in 1967. Other alumni include two first basemen with the last name Clark (Jack and Will), Johnny Mize, Ducky Medwick, Steve Carlton, Willie McGee and two prominent current Cardinals: Manager Mike Matheny and right fielder Carlos Beltran.