Four division races and two Wild Card berths are undecided with three days remaining in the regular season, and one of the races is deadlocked -- the American League East, between the Yankees and Orioles. So it's a real possibility that at least one tiebreaker game, which would be played on Thursday, will be needed.
(NOTE: The National League used best-of-three series to break first-place ties and determine pennant winners in 1946, '51, '59 and '62.)
If history is a guide, there's a good chance that seasons that come down to one game won't be decided until the final out. Eight of the one-game tiebreakers have been played since divisional play began in 1969, and half of them -- including the past three -- have been decided by one run.
That includes one of the most famous games of all. On Oct. 2, 1978, Bucky Dent's home run through the late-afternoon shadows and over Fenway Park's Green Monster proved decisive in the Yankees' 5-4 win over the Red Sox that gave New York the AL East title.
But who can forget the Rockies' amazing 13-inning, 9-8 win over the Padres in 2007? Colorado, in fourth place after losing on Sept. 15, went on a tear, winning 13 of its last 14 games to tie San Diego atop the NL West.
In the one-game tiebreaker at Coors Field, the Padres scored twice in the top of the 13th. But the Rockies stormed back with three in the bottom of the inning. Matt Holliday drove in the tying run with a triple and scored the game-winner on Jamey Carroll's sacrifice fly.
Since tiebreakers are considered part of the regular season, Holliday's two RBIs gave him the league lead over Phladelphia's Ryan Howard. Padres fans still insist Holliday never touched the plate on the last play of the game.
The opposing managers were Bud Black for San Diego and Clint Hurdle for Colorado. Both identified what makes a one-game tiebreaker unique.
"In this situation, it depends on how you get in and when you get in," Black said. "Whether it gives you an opportunity to start the guy you want to start. That's the main thing.
"Once the game starts, it really affects how you use your bullpen, how you use your bench, how early you start to make decisions that affect that particular game. So often, the moves that you make during regular-season games, you have an eye on tomorrow and the following day, to make sure we're in a position to win those as well. In a one-game playoff, there's truly no tomorrow. So every move you make is about that game."
Added Hurdle, who now manages the Pirates: "All we did as a staff, we said, 'It's another game. Yes, it's lose and go home, but it's another game.' Don't overlook anything, don't take anything for granted. Stay connected, because what can happen at times, you get so intent on just watching. Because of the heightened awareness of the game, you're watching and forgetting about being the manager. We addressed that as a staff, for that game.
"Encourage the players. 'You know what, boys? Every play you make is to win the game, every at-bat is to win the game. Let's just go for it.'"
Ron Gardenhire has the distinction of being the only man to manage in two of these situations. His Twins lost to the White Sox, 1-0, in 2008, on a home run by Jim Thome that cleared two rows of hedges; it was announced that it traveled 461 feet. Minnesota bounced back the next year to beat the Tigers, 6-5, in 12 innings.
For Gardenhire, the thrill of victory doesn't outweigh the agony of defeat. Because of that, he's not fond of the new Wild Card system.
"That's real exciting for one day, and then somebody goes home and you're still ticked off," Gardenhire said. "So I don't know. One game. You play 162 to play a one-game playoff. I don't know about that.
"You work that hard all summer long, and now all of a sudden, because of another Wild Card team, you get one game. That could go in the first inning. You give up seven runs, there goes 162 ballgames out the window because of one bad inning. You should have a better opportunity than that."
Ozzie Guillen, now with the Marlins, managed the White Sox against Gardenhire in 2008 and isn't enamored of the one-and-done Wild Card concept, either.
"My opinion, we should play 159 games, and have a three-game playoff," Guillen said. "That would be more exciting, rather than one game. Shorten the season a couple days. Have a day off and play the three games, two out of three. It's more fun for the fans."
But there is no apparent appetite for shortening the regular season. And while best-of-three was once the standard tiebreaker in the NL, that was during an era when pennant winners moved directly to the World Series.
Even some of the one-game tiebreakers that were decided by more than a run were packed with drama. The Cubs beat the Giants, 5-3, in 1998 by surviving a ninth-inning rally attempt by San Franciso. The Mariners thumped the Angels, 9-1, in 1995, but that was a 1-0 game going into the seventh.
So while there's no way of knowing what will happen if tiebreaker games are required this week, or in the Wild Card games on Friday, odds are that the result will be close, exciting contests that will provide plenty of drama for fans.