Even though the Dodgers lasted until Game 6 of the NLCS, the turning point occurred in the third batter of Game 1.
That's when Hanley Ramirez was beaned in the ribs by a Joe Kelly fastball. Adrian Gonzalez and Yasiel Puig struck out after that, and the Dodgers never were the same.
From there, Ramirez was practically in a no-win situation. If he sits out, people question if his mere presence is enough for the Dodgers to boost their chances of winning. If he plays, he's so banged up that he's essentially a singles hitter in the #3 spot. In other words, he's another version of Andre Ethier.
The numbers for HanRam this season are very telling. Let's break it down between regular season, NLDS, and NLCS.
.345 AVG, .402 OBP, 25 2B, 2 3B, 20 HR, 57 RBI, 10 SB
.500 AVG, .556 OBP, 2 2B, 1 3B, 1 HR, 6 RBI, 1 SB
.133 AVG, .316 OBP, 0 2B, 0 3B, 0 HR, 1 RBI, 0 SB
No surprise there.
Ramirez has played the entire season with some sort of injury, including his thumb, hamstring, back, and then his ribs. The fact that he was still able to put up such great numbers shows the talent he has.
But a broken rib is a broken rib, and any athlete would have a hard time playing through that. Add in the fact that he's a baseball player, and his ribs feel the pain each time he swings a bat and makes a throw, I don't think his 2-for-15 performance against the Cardinals is shocking at all.
The beaning also affected him on defense, as he was clearly reluctant, and possibly not even able to, dive for some hard grounders in his area. Who knows if he would've gotten to them anyway, but the Cardinals were able to knock Clayton Kershaw out of Game 6 early because of those hits, so his lack of range on those didn't help.
It's not fair to pin the entire series loss on just Ramirez getting hit, as plenty of other guys didn't step up when they were needed the most. But as the saying goes, Ramirez was "the straw that stirred the drink," and without his production, everybody else suffered as a result. He couldn't hit like his normal self, and the Dodgers averaged 2.2 runs per game.
That's what ultimately did them in.