BOSTON >> Security officials in Boston today were preparing for an extraordinary day of World Series baseball and politics in which a presidential visit may be the least disruptive event.

The Red Sox were hosting the St. Louis Cardinals tonight with a chance to win their third World Series in less than a decade and first at home since 1918. Hours earlier, President Barack Obama delivered a speech on his embattled health care reform.

Obama is expected to be out of town an hour before the game begins, and officials say they’re prepared for any postgame celebration later in the evening if the Red Sox win.

"We’re always worried we might have a couple of knuckleheads who want to cause trouble," said Boston Mayor Tom Menino. "So we’re going to be out there doing our job."

Boston has hosted several celebrations over the last decade as the Celtics, Patriots, Bruins and Red Sox have all won titles since 2004, but some of the post-championship partying has caused problems. In 2004, a 21-year-old college student was killed by a pepper pellet fired by Boston police during crowd-control efforts following the Red Sox win in the American League Championship Series. In 2008, a 22-year-old man died after police took him into custody during street celebrations of the Celtics’ title.

Police Superintendent-in-chief Daniel Linskey said the department has adjusted its tactics to keep crowds at more manageable sizes and keep the overall temperature of the event down. For instance, police won’t wear riot gear, but will instead mix with the crowd in regular uniforms, explaining why certain restrictions are in effect.

"If we just put up a line and tell people, ‘You can’t walk down this street,’ sometimes we get some pushback," he said. "We’re going to try and engage the crowd and make them be partners with us."

Police also would limit crowds near the park by forbidding any entry into Fenway and the streets around it after the seventh inning, Linskey said.

Police Commissioner Edward Davis said, in light of the April bombings at the Boston Marathon, police will deploy extra bomb-sniffing dogs and undercover officers, as well as officers trained to spot suspicious behavior.

City officials encouraged residents to take public transportation Wednesday to relieve congestion, and Menino asked downtown businesses to let workers go home early, if possible. Parking restrictions were in effect around both Fenway Park and Faneuil Hall, where Obama is scheduled to speak.