At least with baseball we have a schedule to follow, and with that in hand, combined with first-half performances and tendencies, it can give us indications of what we might expect from some of the contenders between now and October.
Not that there are any guarantees, in equities or pennant races.
"Every year it seems like somebody surprises you," Cubs manager Lou Piniella said. "Look at last year at the break, how many people predicted Colorado would go on a run like that? The Phillies?"
Every year there are second-half stunners and disappointments. The Rockies, Phillies and Yankees played their best baseball after the All-Star break last season. Players get hot, but the schedule can also take a favorable turn at an opportune time.
Which teams are poised to be this season's second-half bulls? And which ones look like bears?
Here's one fearless forecast:
Angels: Even without factoring in that their closest pursuer, Oakland, is nine games back and recently traded pitchers Rich Harden, Chad Gaudin and Joe Blanton, the Angels were already a strong buy in the American League West.
They have the best record in baseball (60-38) and the best road record (31-18) by a considerable margin. The Angels' road record is better than the home records of all but six of the 30 teams.
The second-half schedule is kind: From Aug. 4 through season's end the Angels will play 29 games at home and 22 on the road. A few of those road series have higher stumbling block potential, such as Chicago, Tampa Bay, Oakland and Texas, but the Angels have played very well within the division (19-12) and have more than held their own against the East (15-9) and Central (16-9).
Brewers: Milwaukee had the best home record in the National League last year and only the Cubs have a better home record than the Brewers (31-17) this year among NL teams. The Brewers have the best record (23-16) within the division.
The Brewers haven't had a winning road record since 1999, and are 24-26 away from home this year.
On the plus side, they've added CC Sabathia, they have one of the best records in baseball since late May and most of their remaining games are at home. There's one more thing: Of Milwaukee's remaining road games, only 13 are against teams with winning records.
Diamondbacks: Arizona has cooled off considerably since the fast start, but they still have one of the best rotations in baseball and pitching should give them the edge the rest of the way in the NL West race.
The schedule is also favorable, with most of the remaining games within the division, where the Snakes are 22-12. They will also have most of their remaining games at Chase Field, where they are 28-21.
Marlins: The pesky Fish won't go away. They've got Josh Johnson back, the team batting average for July is .256 and the Marlins have enough going their way to think they will be in the playoff picture.
The Marlins have been consistent, never falling too far off the pace, and they are one of four NL teams with winning records against all three divisions.
The Marlins are a game under .500 away from home, and 31 of their final 60 regular-season games are on the road, but this is a team that isn't decidedly disadvantaged away from home. Their slugging serves them well regardless of the venue.
Should the Marlins still be playing in October, they certainly will have earned it after road series against the Phillies, Braves, Mets, Cardinals, Cubs, Diamondbacks and Giants, in addition to a makeup game at Cincinnati on Sept. 22.
Phillies: They've been among the better second-half teams in recent years, and this year should be no exception.
The Phillies are one of only three teams with winning records both at home and on the road, noteworthy for a team with a schedule that is split almost 50-50 home and road the final two months. The Phillies are one of four NL teams with winning records against all three NL divisions.
The Phillies also have 11 games left against the NL West, a division Philly is 14-7 against this season. And after their current road trip ends, the Phillies will have just two three-game road series left against the Marlins and Mets. The other eight games against New York and Florida will be played in Philadelphia.
Rays: The Rays stumbled into the break but that may be nothing more than a hiccup on what should be a path to the postseason for surprising Tampa Bay.
The Rays, 38-15 at Tropicana Field, have a seven-game road trip to Kansas City and Toronto beginning this week. After that, 25 of their final 53 are at home.
If the Rays can get through a 10-game road trip to Seattle, Oakland and Texas in August (Tampa Bay is 19-25 on the road) in good shape, the Rays should be in position to weather a tough September schedule that includes home and road series against the Red Sox, Yankees, Orioles and Blue Jays plus a four-game set against the Twins at the Trop on Sept. 18-21.
Red Sox: Another team that has had problems on the road (21-32), the Red Sox remain a bullish pick.
One, they're getting David Ortiz back soon.
Two, despite their road struggles, a 20-19 record within the division and injuries, they stayed at or near the top of the division.
Three, the Red Sox will play 19 of their final 27 regular-season games at Fenway Park, where they are an AL best 36-11 this year.
White Sox: With 13 of their last 20 at home, the White Sox should be in good shape if they can get to Labor Day still on top in the AL Central.
The White Sox are 13 games over .500 within the division and have 30 games against divisional opponents the rest of the way. They also have only one trip to the West Coast remaining, a three-game series at Oakland Aug. 15-17.
Cubs: Cubs manager Lou Piniella knows it as well as anyone.
"Our road record needs improving," Piniella said Saturday after the Cubs dropped their second consecutive game after the break. "We don't score as many runs on the road -- not even close."
The Cubs have not only played poorly away from Wrigley Field, they are only four games over .500 within the division and have only three games left against NL West opponents, a group against which the Cubs built a 22-8 record before the break.
The Cubs are 37-12 at home, where they've hit .305. They are 21-28 on the road, where they've batted .256. The Cubs have averaged 6.29 runs per game at Wrigley and 4.29 away from the Friendly Confines. They've hit 67 home runs at home, 43 on the road. The team on-base percentage is .387 at home, compared to .327 on the road. The slugging, .491 to .395, and the team ERA is 3.72 at home, 3.97 on the road.
Should such a lopsided disparity continue, the Cubs could be in trouble.
The Cubs do not have a day off until Aug. 7 and have 10 of their first 14 second-half games on the road, including four at Milwaukee at the end of the month. Chicago plays 19 of 29 games at home through Aug. 10.
Getting leadoff man Alfonso Soriano back from the disabled list, perhaps as soon as Thursday, will help, but the Cubs know this task is more than one man.
Since going 20 games over .500 on June 15, the Cubs are 13-15.
"We've maintained our lead, we've done that, but that's about it, we had a chance to add on," Piniella said. "Hopefully getting Sori back will give us a spark. But it's obvious we've got to play better on the road."
Especially considering some of the road series the Cubs have from here to October. After finishing in Houston on Sunday, the Cubs have three in Phoenix against the NL West-leading Diamondbacks. A few of the other road stops during the final two months include Milwaukee (twice), Atlanta, Florida, St. Louis and the Mets.
The Cubs' final stretch in September includes a road trip to Cincinnati, St. Louis and Houston followed by a six-game homestand against the Brewers and Cardinals. Chicago finishes the regular season with a seven-game road trip to New York and Milwaukee.
Mets: Don't let their longest winning streak since 1991 hide some of the cracks in New York's second-half picture.
They've played well lately, granted, but all but three of the Mets' wins in that 10-game streak came at home and all but three were against teams with losing records.
The Mets are 25-28 on the road and 18-16 against NL East foes. Of New York's last 56 regular season games, 27 are on the road, and 25 of the remaining home games are against such talented teams as the Cubs, Cardinals, Phillies, Marlins and Braves.
The Mets clearly have the talent to make it to October, but between now and then the schedule clearly isn't on their side.
Cardinals: It would be a mistake to dismiss this overachieving team.
The Cardinals have winning records at home and on the road, against all three divisions, and finished Interleague Play at 7-8.
Like most Tony La Russa teams, they are playing better as the season progresses. They are also getting healthier.
Even so, they face a daunting task trying to outdistance the Brewers and Cubs, and the second-half schedule is replete with all of the heavyweight contenders.
Twins: Another surprise team, the Twins made hay against the NL (14-4) and have been outstanding at home (34-19). They also lead the Major Leagues in hitting with runners in scoring position. Considering how well Ron Gardenhire's team has done up to now, you would think we would have learned to quit underestimating the Twins.
But the fact remains the Twins have been a sub-.500 team on the road and also vs. the other two AL divisions, and they have plenty of games involving all three the rest of the way.
The schedule isn't kind, as Minnesota plays 35 of its final 63 regular season games on the road, including a 14-game road trip against the Angels, Mariners, A's and Blue Jays Aug. 21-Sept. 4.
Yankees: Remembering what they did in the second half last season is all you need to know about the Yankees not to write them off this season.
And yet, the AL East is much tougher this time and the Yankees, like Boston, are only 20-19 against division opponents. New York has at least managed to play .500 ball on the road.
The Yankees have other hurdles to clear, like two road series against the Angels, two West Coast trips and a brutal second half that includes games against the Angels (10), Red Sox (6), White Sox (4), Rays (6) and Twins (6).
Jim Molony is a reporter for MLB.com. MLB.com reporters contributed. This story was not subject to the approval of Major League Baseball or its clubs.