The 2009 Major League Baseball season opens on Sunday evening when the Philadelphia Phillies begin the defence of their World Series title at home to the Atlanta Braves. However, as far as the baseball fans of New York City are concerned, the excitement begins this evening, when the Mets and Yankees play the first exhibition games in their new stadiums - each one built less than a home run from their old ballparks.

The new Yankee Stadium is effectively an improved version of The House That Ruth Built, with many architectural echoes of its renowned 1923 predecessor across the street. Citifield, which the Mets have built in the car park of Shea Stadium, their home since 1964, is also a step forward and a look back. As well as the modern comforts that today's fan expects, it has features that recall Ebbets Field, the sorely-missed home of the Brooklyn Dodgers until they decamped to Los Angeles in 1958.

The building of extravagant new venues in difficult financial times has been criticised in some quarters, not least because of the part-use of public funds. The Yankees, the richest franchise in baseball, have effectively been given a $20 million contribution from the public purse through the sale of $1.3 billion of tax-exempt bonds. The Mets have been backed by $637 million in such bonds, but, even more controversially, have also attracted $400 million in naming rights from Citigroup - who have received a $45 billion government handout, albeit after the deal with the Mets was done.

Both venues will recoup the investment many times over in the long term, such is New York's passion for baseball. The clubs, though, will begin benefitting immediately from increased revenues from the premium seats, restaurants and suites that their old grounds lacked, which is just as well - both have, as usual, invested heavily in new players in attempts to improve disappointing recent records.

The Yankees, who have not appeared in the World Series since losing to the Florida Marlins in 2003, have strengthened their pitching rotation by signing CC Sabathia, the dominating former Cleveland and Milwaukee hurler, and AJ Burnett, a rather more brittle performer, while adding power to their batting line-up in the shape of Mark Teixeira, the former Texas Rangers first baseman.

The Mets seemed on course for the play-offs in each of the past two seasons only to fall short at the death, but they have now addressed a serious weakness in their relief pitching with the acquisition of Francisco Rodriguez - a dominating closer known as "K-Rod", who saved a record 62 games for the Los Angeles Angels last season - and JJ Putz, the former Seattle Mariners closer, who will pitch the eighth inning and, the Mets hope, hand Rodriguez a lead to save.

In the circumstances, it would not be a surprise if the two teams reached the World Series in October. And although the rest of the United States and Canada would recoil at the prospect of the widely-disliked New York teams disputing a first Subway Series since 2000, they could not argue that the new New York ballparks would not be worthy stages.