With about one-third of the regular season now in the books, we have a clearer picture about those teams that are taking the lead in the race for a World Series pennant—leaving the would-be threats in the dust for good.

But some of these starts are simply illusions, with teams that have not yet exposed their frailties. That said, let’s highlight the truths and showcase the frauds.

Contenders

San Francisco Giants (32-19, 1st in NL West)
The Giants of 2013 this is not. One sign of strength is the ability to hold a lead.

San Francisco is 24-4 in games in which it scores first. The pitching is a big reason to thank for that, with a team earned run average (ERA) of 3.15 and Sergio Romo’s 16 saves—good for second-best in the majors.

The offense has slugged 60 home runs (only Colorado has more in the NL) with a consistent lineup led by Buster Posey, Brandon Belt and Michael Morse. Without question, the Giants are not just a legit threat to L.A. in the West, but are presently a strong contender for a third World Championship in five years.

Toronto Blue Jays (31-22, 1st in AL East)
What was expected in 2013 has finally crystallized in 2014. With 19 wins in May, including a recent home sweep of the Oakland A’s, Toronto has surged to the lead in the AL East and has the tools to stay there. Edwin Encarnacion is emblematic of his team’s uprising, with 14 home runs this month—including one on Tuesday that pushed his season total to 16 and Toronto’s win streak to eight.

Even when he cools off, the lineup also possesses the power threats of Jose Bautista and Melky Cabrera. R.A. Dickey has recently found his groove on the mound, nicely complementing the season-long efforts of lefty Mark Buehrle. A winner in four of his past five decisions, Dickey nearly went the distance in a stellar outing on Saturday versus Oakland. Buehrle, meanwhile, ranks first in wins (nine) and is among the leaders in ERA (2.33).

Milwaukee Brewers (30-22, 1st in NL Central)
Seven losses in 10 games would give one reason to question the Brewers’ staying power. Compound that with the surging Cardinals, and it’s quite apparent Milwaukee’s grip on first place in is slipping. That’s impossible to argue against, but there are reasons to believe the Brewers are still for real.

Francisco Rodriguez can’t keep up the pace he had in April. However, he’s back to being one of the game’s dominant closers. With a healthier Ryan Braun in the middle of the lineup, the offense becomes significantly better. They may not be able to fend off a Cardinals team that has recently come to life, but a playoff spot is certainly attainable. Not bad for a club that was supposed to do next-to-nothing when spring training concluded.

Los Angeles Angels (28-22, 2nd in AL West, 2.5 GB)
A team with Mike Trout and Albert Pujols shouldn’t have been out of contention for the past two seasons. Trout has been outstanding since coming on the scene in 2012.

But the Angels’ struggled in underwhelming performances that were mostly due to injuries, with Pujols being among those banged up far too often. For the moment, the team has remained healthy and the future Hall of Famer is having his best season since signing with Anaheim: 14 home runs, 13 doubles and 31 RBI. Should this continue, there’s no reason to doubt the Angels’ legitimacy.

Pretenders

Miami Marlins (27-25, 2nd in NL East, 2.0 GB)
No Jose Fernandez, no chance.

While that’s not entirely true, especially when the Marlins still have Giancarlo Stanton wielding a bat for them. But the likelihood of Miami keeping up with the Braves and other NL contenders is very slim.

Fernandez’ replacement, veteran Randy Wolf, made supporters in South Beach long for the 21-year-old phenom pitcher by allowing nine hits and six runs on Sunday—his first start with the Fish. The offensive boom (second in the NL in runs scored) has been a major surprise so far, but the pitching staff won’t be able to recover from the loss of their ace.

Colorado Rockies (27-24, 3rd in NL West, 5.0 GB)
The only team higher than the Marlins on the run-scoring totem pole is the one from the Mile High City. Led by the expected greatness exhibited by Troy Tulowitzki and Carlos Gonzalez, along with the unexpected consistency of Nolan Arenado and Charlie Blackmon, Colorado has been in contention through the first two months of the year by hitting its way to the top.

While Tulo has the ability to at least maintain his current rate, conventional wisdom suggests the rest can’t keep pace. It doesn’t help when health becomes an issue—as Gonzalez and Arenado have been missing from the lineup.

More importantly, what wins down the stretch (and in October) is pitching. As is the case with Miami, the Rockies—ranked 25st in team ERA—are doomed with this weakness.

Chicago White Sox (26-27, 2nd in AL Central, 5.0 GB)
When the Detroit Tigers look down in the standings, they see four teams simply vying for second place. Manager Robin Ventura and the White Sox currently hold that spot, and the start has certainly given reason for hope. Of the team’s 55 homers, 15 have come off the bat of rookie Jose Abreu, who is currently nursing a left ankle injury with an unknown return date.

Losing the primary offensive force is one reason why Chicago is only going to spend September as spoilers. Inexperience is the another. The Sox have nary a chance at catching the Tigers and the playoffs are a long shot.

Ventura and company would deem a .500 season as a great success and as they embark on a bright future with Sale and Abreu as the anchors, but this probably isn’t their year to take home the AL Central crown.