For the second half of the regular season, the Achilles' heel for the Giants was their bullpen, and Tuesday night it blew a three-run lead in the ninth inning as the Chicago Cubs eliminated the Giants from the postseason.
After 103 wins during the regular season, the Cubs expect to win no matter what happened Tuesday night. Not having a lead during Game 4 until the ninth inning didn't faze the Cubs, even though they are a young team. A home run by veteran catcher David Ross that tied the game in the third helped bolster the Cubs' confidence.
This is the first time this decade that the Giants have been eliminated when they made the playoffs. After a 13-inning, 5-hour victory Monday night, the Giants' bullpen was exhausted and couldn't protect the lead against a confident Cubs team.
:: NLCS: Dodgers vs. Cubs coverage ::
Giants starter Matt Moore, a lefty who was acquired from the Rays at the non-waiver Trade Deadline, was brilliant for eight innings. The offense attacked veteran Cubs starter John Lackey early and often, but the Giants didn't score after the fifth inning.
After having the best record in baseball at the All-Star break, the Giants battled hard to earn the second Wild Card spot. They won a dramatic Wild Card Game against the Mets.
To compete with the elite teams in 2017, the Giants must improve their bullpen. They also need to generate more offense by adding power. Not many teams can go to the playoffs without a player who hits at least 20 home runs, but the Giants did this year. They also need more speed so that they can utilize the running game.
Since Theo Epstein brought Joe Maddon to Chicago before the 2015 season, there has been one goal in mind: To make the Cubs world champions for the first time since 1908. From Spring Training in 2015, they have tried to instill a winning attitude and confidence in the players. The Cubs were knocked out in the NLCS last year.

This season they were practically unstoppable. By decreasing strikeouts, their offense improved. Adding Jason Heyward to play right field and hit behind the young sluggers gave legitimacy to the offense and defense. Dexter Fowler gives them a traditional leadoff hitter. During the NLDS, they created scoring opportunities and took advantage of them.
The Cubs commit a few more errors out of their youthful enthusiasm than many good defensive teams. During the NLDS they were placed perfectly for every grounder and fly ball, whereas the Giants weren't. The Cubs have speed and tremendous athleticism at every position.
The old baseball adage that pitching wins applies to the Cubs. The Cubs have a terrific starting rotation. The emergence of Kyle Hendricks and the continued dominance of Jon Lester and Jake Arrieta have enabled the Cubs to get where they are. If the rotation can continue dominating its opposition, the Cubs will be tough to beat in the NLCS.

The Cubs have an excellent bullpen, an important aspect for any team in the playoffs. When a starter can't get through five innings, the Cubs' bullpen usually has pitched well enough to allow the team to win.
At the non-waiver Trade Deadline, immediately after the Cubs went through their only rough spot during the season, the management obtained Aroldis Chapman, arguably the most dominating closer in baseball. This important acquisition demonstrated to the team that the front office thought they could bring the north side of Chicago a world championship.
To continue to perform well in the NLCS, the Cubs need to take advantage of every scoring opportunity. Their young hitters must stay relaxed and not try to hit a home run in every at-bat. Their defense must avoid errors by not rushing plays. Their pitching doesn't have to shut out the opposition, but they must keep their team in the game.
The Cubs are favored going into the NLCS, but they will receive more of a challenge from the Dodgers than they did from the Giants.