"For some reason, June 1 felt like August 1," Giants general manager Brian Sabean said. "Professionalism never waned, and the effort never waned. But the execution was lacking, there was a lack of performance, and I think that had a lot to do with physical and mental fatigue."
The Giants may have been victims of their success, to a considerable extent. Winning the title required their starting pitchers to work an extra month and thus shortened their offseason. Moreover, of San Francisco's seven Major Leaguers who participated in the World Baseball Classic, five -- left-hander Jeremy Affeldt, third baseman Pablo Sandoval, center fielder Angel Pagan and right-handers Ryan Vogelsong and Santiago Casilla -- spent time on the disabled list. And though second baseman Marco Scutaro avoided going on the DL, he endured back problems.
Right-hander Sergio Romo was the lone Giant among the team's Classic participants to remain healthy this year.
"I don't know if it was bad luck on our part, but something happened to everybody who participated in the WBC," Giants manager Bruce Bochy said.
It seemed that something unfortunate happened to everybody, period. Entering May 13, the Giants owned a 23-15 record and a 2 1/2-game division lead over Arizona. Then they traveled to Toronto, where they were swept in a two-game series.
Nobody knew it then, but that began the Giants' final descent.
For the remainder of the season, the Giants posted a 53-71 record. Their .427 winning percentage in that span was the NL's third-lowest behind the Cubs (50-74, .403) and Miami (51-73, .411).
As is typically the case, the Giants' slump was a team effort, just as multiple players played key roles in their Series triumphs in 2010 and '12.
The club's 4.00 ERA was its highest since 2008 (4.38). The Giants scored 629 runs -- 10th in the league and a decrease of 89 runs from the previous season. Their average of 3.5 runs per game at home ranked as the NL's third-lowest.
That reflected the Giants' diminished home-field advantage. They finished 42-40 at AT&T Park, their worst record by the Bay since a 37-44 finish in 2008.
Here's a final review of the 2013 season, highlighted by the year's top five storylines:
5. Pagan's injury an ominous sign
Misfortune tempered one of the season's biggest thrills. Pagan lashed an inside-the-park, walkoff home run in a 6-5, 10-inning triumph over Colorado on May 25 but injured his left hamstring during that game, requiring surgery that sidelined him for 82 games.
The Giants missed Pagan's assertive presence in the leadoff spot. His absence hampered No. 2 hitter Marco Scutaro, who saw fewer fastballs and couldn't employ his hit-and-run skills as often without Pagan reaching base ahead of him. Scutaro hit a respectable .297 but collected 31 RBIs in 127 games, compared with 44 in 61 games in 2012.
Without Pagan and Scutaro galvanizing the offense -- "We had a tough time overcoming that," Bochy said -- San Francisco's lack of power was doubly pronounced. The Giants could get away with hitting the fewest homers in the NL (103) in 2012, because they excelled at situational hitting. They didn't this time around, so ranking next-to-last in the league with 107 homers became a flaw.
4. Rotation spins off its axis
San Francisco's starting pitching, considered an elite group for years, was merely ordinary. The starters' 4.37 ERA was the league's third worst and the team's highest since 2006 (4.58).
Giants pitchers struggled at the outset and needed time to regain their equilibrium.
Matt Cain was 5-6 with a 5.06 ERA in 19 starts before the All-Star break. One year earlier, he started the All-Star Game for the NL.
Tim Lincecum, continuing his transition from relying on power to embracing precision, posted a 5.12 ERA in his first 11 starts and lost nine of his first 13 decisions.
Ryan Vogelsong compiled a 1-4 record with a shocking 8.06 ERA in his first eight starts.
Barry Zito fell from his 2012 grace, twice enduring removal from the rotation and recording an 0-9 record with a 10.00 ERA in 11 road starts.
Only Madison Bumgarner displayed any semblance of consistency, amassing 22 quality starts and making his first All-Star team.
3. Mid-year momentum fades
The Giants trailed division-leading Los Angeles by 6 1/2 games after Lincecum threw his dynamic no-hitter at San Diego on July 13. It was the kind of inspiring effort that can propel a team to greater heights. In fact, the Giants won their first two outings after the All-Star break to trim their deficit to 4 1/2 games.
Then the Giants forgot how to hit. They lost eight of their next nine games, scoring three runs or fewer in each defeat. Just like that, they trailed by 11 games, because the Dodgers were in the midst of a stretch of 42 wins in 50 games.
2. No help forthcoming
In previous years, farmhands such as Buster Posey or Bumgarner or midseason acquisitions like Pat Burrell, Hunter Pence or Scutaro rallied the Giants. This time, they had no Major League-ready performers with surpassing talent, and the additions of Jeff Francoeur and Kensuke Tanaka proved meaningless.
"We didn't have enough depth," Sabean said. "Last year we seemingly were able to overcome injury and lack of performance. We didn't do that this year. We didn't get any kind of life-raft help from the Minor Leagues, whether it was the fifth starter or what we went through in center field and left field."
1. Pence leads late surge
It's often said that September baseball is illusory. The Giants hope this isn't true. They played their best in the season's final month, fashioning a 16-11 record to avoid joining the 1998 Florida Marlins as the only teams to finish last one season after winning the World Series.
Pence proved indispensable, earning NL Player of the Month honors with 11 homers, 32 RBIs, a .667 slugging percentage and 23 runs. His surge helped earn him a five-year, $90 million contract extension that was forged during the season's final weekend and prevented him from entering free agency.
Pagan's return also helped. He was reinstated from the 60-day disabled list on Aug. 30 and batted .323 (30-for-93) in his final 25 games.