BOSTON -- This postseason, Dodgers ace Clayton Kershaw has now put together two dominant starts and two clunkers. Every time there's a dominant start, one side of the internet starts to scream down the narrative that he can't handle the postseason pressure. Every time there's a dud, the other side of the internet screams back, "I told you so!"

It can be exhausting, but I also think it's fascinating. For some reason, he seems to alternate between a dominant start and a bad one. In the NLCS, he wasn't very good in Game 1, but he was outstanding in Game 5. Here in Game 1 of the 2018 World Series, we got another dud. 

Clayton Kershaw
LAD • SP • #22
View Profile

Maybe he pitched better than the line suggested, but that's a pretty ugly stat line. There's no getting around that. That outing is one of the reasons the Red Sox won, 8-4, and have taken a 1-0 lead in the best-of-seven World Series

One thing that stuck out to me in the NLCS was the difference in Kershaw missing bats with his slider, one of his two main pitches along with the fastball. His curve is his out pitch that is used less than 20 percent. Otherwise it's all fastball and slider. 

In NLCS Game 1 (dud), Kershaw didn't get a single swing-and-miss with his slider. In NLCS Game 5 (stud), Kershaw got 10. That's pretty much the entire contrast in the two starts, from a pitch-selection standpoint. As such, perhaps the same thing happened on Tuesday. 

Let's walk through the innings in World Series Game 1. 

First inning

Kershaw threw 11 sliders and only got one swing-and-miss. The takeaway from seeing that stat is it probably means he had a bad inning. Sure enough, he gave up two runs on three hits. Get this: All three hits were against the slider, driving home the two runs. 

Second inning

He threw six sliders and got one swinging strike. It was a strikeout in a scoreless inning. 

Third inning

He threw nine sliders and only got one swing-and-miss. He allowed a run on a J.D. Martinez RBI double to deep center field that would've been a home run in many ballparks. It came off of, you guessed it, a slider. 

Fourth inning

This is Kershaw's only 1-2-3 inning of the night. Before looking it up, the guess would be his slider was working in the inning. He threw seven sliders with only one swing-and-miss, however, he got two called strikes and a foul ball. He finished a looking strikeout of Sandy Leon with it. 

Fifth inning

He would only face two batters, but both reached base and ended up scoring. Mookie Betts walked after taking a slider for ball three and fouling off four straight sliders before taking ball four. Andrew Benintendi then hit a rocket single on a slider on the first pitch and Kershaw's day was done. His seven sliders in the inning got zero swings and misses. 

On the day, Kershaw got four swings-and-misses on his slider, which was thrown 40 times. In at-bats that ended with a slider, the Red Sox were 5 for 9 with three RBI (all three runs that were driven in with Kershaw on the mound). 

"I don't think he had the fastball command that he typically does, missing up in the zone," manager Dave Roberts said afterward. "I don't think his slider had the depth that we're used to seeing. Those guys, to their credit, they put up some good at-bats against him. We didn't play the defense that we typically do. I thought we left some outs out there. It didn't make Clayton's job any easier."

Nor did a tight strike zone. 

"I'm sure there were some pitches he threw that he thought he deserved, but it was the same strike zone for both sides," said third baseman Justin Turner. "You can't really complain about it." 

And Kershaw didn't. He made no excuses and instead praised the Red Sox. 

"I felt fine," he said. "I didn't pitch very well, but I don't think the weather had anything to do with it." 

"That's a hard team to beat. They do a great job all the around. They can hit homers, they can beat you by putting the ball in play, getting singles, working counts, getting walks, stealing bases, all sorts of things."

A combination of the Red Sox's destructive offense and Kershaw lacking command and bite on his slider doomed the Dodgers from the get-go. 

If Kershaw's not getting more misses on his slider, he's going to have outings like this. His fastball isn't nearly what it used to be and his curve isn't nearly as effective if hitters don't have to key on a put-away slider, like he had in Game 5 against the Brewers last round. 

This is something to keep in mind if the series gets to Game 5. It was evident in the first inning that Kershaw didn't have his good slider. As we've seen now in five starts this postseason, that's where everything has to start with him. Without commanding that pitch and getting swings and misses, he's simply not the same pitcher we've long since been accustomed to seeing.