Complex sentence: The Mets and the Cardinals met in the NL Championship Series, with the Cardinals becoming the National League champion and going on to face the American League champion Detroit Tigers in the 2006 World Series.
Split into simpler sentences: The Mets and the Cardinals will meet in the NL Championship Series, with the winner of that series becoming the National League champion. The NL champion will face the American League champion in the 2006 World Series.