Shabbat, which begins at sundown every Friday and ends at sundown on Saturday, is a day of rest. Those who observe it do not work or use machinery or drive or cook.
On Yom Kippur, the rules are even more stringent. "So there's not really a way to be informed about what's happening in the game because it would involve electronic means," Zeff said.
There are ways around the rules, like turning on the TV while the sun is still up and leaving it on.
"You could do that," Zeff said. "But it's about what's technically permissible compared to what is the intent of the holiday. . . . This is supposed to be a day when you're reviewing yourself as a person, making an accounting of the soul, and focusing on the things that are really important."
He laughed, perhaps a little wistfully. He is, he acknowledges, a loyal fan.
One of the few decorations in his office is a Roy Oswalt bobblehead. He also treasures a baseball autographed by Jesse Biddle, the local kid who was signed to the Phillies in 2010.
And he will not be surprised, he said, if some in his congregation are secretly checking their iPhones for the scores during Kol Nidre, the Yom Kippur services.
Personally, Zeff said, he plans to read Saturday's paper eagerly as soon as it arrives on his doorstep.
"It's an interesting conflict," he said, "because at least in Philadelphia, Jews are really into baseball."
During trying times like these, it helps to remember the example set by the great Sandy Koufax, who declined to pitch Game One of the 1965 World Series because it fell on Yom Kippur.
At Hymie's Delicatessen in Merion, a mecca for borscht, matzo balls and rugelach to die for, several regulars, faced with only a hypothetical choice between their team and their faith, expressed disapproval for anyone who failed to respect Jewish tradition.
"Not that I'm judging anyone," said Barbara Caplen, "but this is our highest holy day. I'm happy for the Phillies. I want them to win. But we just can't do it."
Caplen had never planned to attend the game. Her son, however, did, and (thank goodness) gave his tickets away.
Caplen manages an antiques store in Chestnut Hill and was having lunch with her boss, Gerald Schultz, who played minor league baseball in the 1950s. "He was a lefty pitcher!" Caplen said.
"Stop," Schultz demurred.
"You were!" Caplen said. "He played with Willie Mays!"
With a little prodding, Schultz confirmed his pro-ball past, even indulging in a few memories. He was 13-10 for the 1952 Muskogee (Okla.) Giants, according to www.baseball-reference.com.
A longtime Phillies fan, he said he had no intention of going to the Friday playoffs. But he had no compunction about watching it on TV.
"I'm not religious," Schultz said. "I don't belong to a synagogue. But if I had tickets, I wouldn't go to the game." He wants to set a good example for his eight grandchildren. "Tradition has to carry on."
Truthfully, for most observant Jewish season-ticket holders, the decision to forgo the game was not terribly difficult.
"It's one of those necessary responsibilities," shrugged David Gordon, who gave up his right-center-field seats. "You just know how it's going to play out. It's nonnegotiable."
Gordon, 59, a surgeon from Allentown, was at Hymie's on Thursday, packing in one of his last meals before the fast.
The restaurant was noisy and crowded and warm, the Reuben sandwiches packed so thick with pastrami that your order should come with a side of Zocor, the mood as bubbly as Dr. Brown's Cel-Ray soda, and the air redolent of Chanel, challah, and onions.
Another customer, Arthur Werblun, overheard that Gordon held season tickets and asked whether he could buy them.
"I'm a conservative Jew," said Werblun, a 54-year-old retired auto-parts salesman. "I was bar mitzvahed. But if I had tickets, I would definitely go. It's sports history! You need to support your team. You need to support your religion, too, but you can do that any time."
Gordon sympathized, but told him, unfortunately, he had already passed the tickets along to a friend.
Of the Jewish persuasion.
Which might sound like a punch line but isn't. For a real joke about this sacred-tickets-to-the-game vs. sacred-religious-obligations pickle, you have to consult Harry Zeisler, Hymie's manager.
"I have this customer," he began. "He calls his rabbi and says, 'Rabbi? I have a problem. I have tickets to the Phillies-St. Louis game and it's Yom Kippur. What should I do?' "
"No problem," says the rabbi. "You can record it!' "
"Oh!!" the customer cries. "That's great! I didn't know you could record Kol Nidre!!"
Contact staff writer Melissa Dribben at 215-854-2590 or email@example.com.