As the Kings and Rangers entered the 3 period of Game 1, they had played a very even contest. LA had the slight edge in scoring chances at evens, the Rangers had the edge slight edge in possession (35 attempts for and 31 against). Then soon after the Kings finished killing a penalty :41 seconds into the third, they began to dominate.
In fact, their domination in that frame was historic:
Kings outshot Rangers 20-3 in 3rd period in Game 1. The +17 shot differential is largest in a Cup final period since expansion in 1967-68— Yahoo Sports NHL (@YahooSportsNHL) June 5, 2014
What happened? Why did the Kings become an unstoppable force in the third after two evenly played opening sets?
Seemingly unhappy with the play of some of his forwards, Darryl Sutter had toyed around with his line combinations early in the game. By the third, he was done toying with them and ripped them apart until nothing recognizable was left.
During the third period and overtime, Sutter iced 15 different forward line combinations in 22 shifts at evens. This threw a wrench in the gears of what had been a very effective Rangers' gameplan, and they couldn't come up with a solution.
Jeff Carter bore the brunt of Sutter's line shuffling, as he saw time with 11 different forwards. He had been LA's best forward through the first two periods in terms of possession numbers, and he continued to dominate despite his revolving door of linemates in the third.
But the biggest reason behind the Kings' late game dominance wasn't Carter--it was the play of arguably the NHL's best two way forward, Anze Kopitar.
Kopitar had made little impact on the game in the first two periods. He hadn't attempted a shot, and was having trouble pushing the needle forward (5 on ice attempts for, 7 against). In that time, he had seen most of his minutes against Dominic Moore and the Rangers 4th line. Moore was being heavily zone matched to the defensive end by Alain Vigneault and Kopitar and faced Moore virtually every time he had an offensive zone draw.
Moore and his linemates were able to stifle Kopitar's attack by virtue of playing a heavy defense first game. The Rangers 4th line wasn't being counted upon to create any offense, they were being counted on to clog up the ice, deny shots and get the puck out of the zone.
In the third period, Sutter kept Kopitar away from Moore and matched him pretty much exclusively to the Rangers first line. The result?
When Kopitar was on ice at evens in the 3rd period, the Kings were able to attempt 9 shots, while the Rangers only attempted 1. When Rangers first line center Derek Stepan was on the ice at evens in the 3rd, the Rangers were only able to attempt 2 shots, while the Kings attempted 7.
Additionally, Kopitar had 4 shots on goal in the 3rd period alone. Stepan was on ice for 3 of them.
Although Anze Kopitar was kept off the score sheet in Game 1, his play in 3rd period sparked the Kings. He led the charge by constantly keeping the Rangers pinned in their zone late in the game. This freed up the other LA forward units to get easier minutes against what began to look like a fatigued Rangers team and eventually lead to the OT game winner.