No particular series doomed the Giants last year. But if any set of games exposed the weaknesses that would prevent them from reaching the postseason and earning a chance to defend their 2012 World Series title, it was their June 20-23 series against Miami at AT&T Park.
Miami captured three of the series' four games, prompting a Giants slump in which they lost 16 of 19 games and never recovered as they fell below .500 for good.
So while the Marlins have fallen upon hard times, losing ace Jose Fernandez to an elbow injury and dropping five consecutive games before snapping that skid with a 13-3 rout of the Dodgers on Wednesday, the Giants will take them extremely seriously when the clubs begin another four-game series Thursday at AT&T Park.
The Giants will again face Marlins starters Nathan Eovaldi, Tom Koehler and Jacob Turner, who combined to allow four runs in 20 innings in last year's series.
That series began with Miami ensconced in last place in the National League East, 20 games out of first. By contrast, the Giants trailed West-leading Arizona by a mere 1 1/2 games. Obviously, the Giants appeared to be the superior club.
So much for appearances.
The Giants proceeded to go 4-for-32 with runners in scoring position against Miami while hitting a limp .237 (32-for-135) overall.
San Francisco entered the series finale striving to emerge with a series split. Matt Cain, who will oppose Eovaldi in Thursday's opener, responded with one of his better efforts in a dreary first half, allowing three runs in six innings while striking out eight. But Miami tattooed Jean Machi for four ninth-inning runs to pull away.
That left the Giants only three games out of first place, but they nevertheless began a free fall that didn't stop until their record reached 40-50.
So the NL West-leading Giants have no desire to let Miami knock them from their lofty perch again.
Meanwhile, the Marlins remain one of the most baffling teams in the game. They boast a 17-5 record at home, yet on the road, they have struggled miserably. They've already lost their four-game series at San Diego and three-game set at the Dodgers before heading into AT&T Park.
Although the Marlins are 32-49 all-time at San Francisco, they have actually played extremely well at AT&T Park in recent years. They've won 12 of their last 15 games at San Francisco.
On Friday, the Marlins are going with the hard-throwing Eovaldi, who assumes the role of ace now that Fernandez is done for the season with a significant ligament tear in his throwing elbow.
Eovaldi, 24, feels he must carry an extra responsibility to front the rotation.
"It's definitely disappointing, but we'd been throwing the ball so well as a whole, we've got to focus on keep doing what we're doing and keep going out there," Eovaldi said of moving on without Fernandez. "It's definitely a big blow for us. The things he's accomplished and everything he's done for the organization is amazing, especially at a young age."
Eovaldi comes off a no-decision at San Diego in a game the Padres won, 9-3. Miami couldn't hold on after jumping to a 2-0 lead in the first inning. Eovaldi exited after allowing two runs in five innings. He threw 112 pitches, but wasn't able to work deep into the game.
"Every at-bat was like a struggle," Eovaldi said.
Giants: Pence maintains steady production
Hunter Pence's big day Wednesday continued his recent offensive surge. The right fielder went 4-for-5 in San Francisco's 10-4 triumph over Atlanta, hiking his batting average to .348 (31-for-89) while hitting safely in 17 of his last 22 games.
During this stretch, Pence has scored 19 runs while amassing six doubles, two triples, two homers and 10 RBIs.
Overall, Pence leads the Giants with 29 runs. His consecutive-game streak has risen to 212, longest in the NL.
Marlins: Wolf signs, more moves to follow?
Losing Fernandez for the season hasn't caused the Marlins' front office to slow down. Actually, quite the opposite has occurred. Miami on Wednesday announced the signing of veteran lefty Randy Wolf to provide experience to the rotation. The 37-year-old will step into the rotation.
Wolf's signing, for $1 million, also doesn't mean Miami is done surveying the landscape for potentially more pitching. Experienced pitching is sought to help pick up the slack without Fernandez.
"We're always in the market," Marlins president of baseball operations Michael Hill said. "We'll reassess if we need to. This a very tough team. They've dealt with a lot in the first  games. Winning streaks. Losing streaks. We know this team faces adversity. This is another thing we expect this team to address head on, and keep it going."
• Giancarlo Stanton has been one of the most productive hitters in the game all season. The 24-year-old right fielder also has posted big numbers in his career at AT&T Park. Stanton has a career .333 batting average at San Francisco with four home runs and 11 RBIs. Overall vs. the Giants, he is batting .337 with eight homers and 20 RBIs.
• Christian Yelich, raised in Thousand Oaks, Calif., will be making his AT&T Park debut. The 22-year-old, in his first full big league season, entered the road trip not having played at San Diego, Los Angeles or San Francisco. During the trip, he already has homered at Petco Park and Dodger Stadium. He has four games to go deep at AT&T Park as well.
• San Francisco's bullpen chipped in with four scoreless innings Wednesday. That shrank the relievers' home ERA to 0.94.
• The Giants improved to 12-4 in day games. That victory total leads all NL teams in this category.