Is Corey Seager the key player in the World Series?
— -- Network heads may have preferred a World Series matchup between the Los Angeles Dodgers and the New York Yankees, a pairing that stands out as significant with 11 previous showdowns between them, but none since 1981.
But the Dodgers drawing the Houston Astros in the Fall Classic produces the marquee matchup for baseball fans, pitting the best team in baseball in 2017 against the team with the best chance at knocking off that team, at least according to ZiPS projection analysis. But which is which? Both the Dodgers and Astros spent the 2017 season running roughshod over their leagues, establishing insurmountable division leads before the All-Star break. They even both got significantly better with their big midseason pickups, adding Yu Darvish and Justin Verlander, two cases of the phenomenally rich becoming phenomenally richer.
Just like in 2016, one notable World Series drought will be flushed away, the Dodgers having not won a World Series since 1988 and the Houston Astros not since the Big Bang approximately 13.8 billion years ago. (In fairness, baseball didn't exist for most of that period.) Because both teams can't win, let's run down a few X factors that could significantly affect the bottom-line projections.
Corey Seager's attendance: Yes, the Dodgers ended up doing very well in the National League Championship Series despite the loss of Seager, who is either their first- or second-best position player (depending on which version of Wins Above Replacement you use). That's the benefit of having a team with unbelievable depth, as the Dodgers do. But to say that the loss didn't affect their expectations going in is a bit of a fallacy. Charlie Culberson's .455/.417/.818 triple-slash line filling in wasn't exactly a reasonable mean projection for what he was likely to do after he had just 15 plate appearances in the majors during the regular season. Seager is important for any team, and his apparent return for Game 1 of the World Series is a very big deal. The Dodgers' win probability drops by 5 percentage points when comparing a healthy Seager in the lineup and no Seager.
Houston's disappearing bullpen: While the Astros likely won't come right out and admit it, you can see some of manager A.J. Hinch's frustration with the bullpen's performance come out in some of the pitcher usage since the pen blew its 4-0 lead in the seventh and eighth innings of Game 4 of the ALCS, a game that would have put the Astros into a commanding 3-1 series lead. It was only when the Game 6 lead got to five runs that Houston was comfortable pulling Justin Verlander and it was Lance McCullers, not the pen, who was asked to shut down the Yankees with a not-insurmountable four-run lead in Game 7.
ZiPS projects the likely mix of Astros relievers to have a 3.87 ERA right now. But what if they're worse than that, right now, for the four to seven games they have left to play? A half-run difference would knock another 4 percentage points off the Astros' chances.
The Houston rotation: As they did in the NLDS, the Dodgers won the NLCS without a whole lot of drama and fairly quickly. So they can again set their rotation based entirely on how they'd like it to be, meaning we're likely to see a rotation sequence of Clayton Kershaw, Rich Hill, Darvish and Alex Wood, with Kershaw possibly coming back for a Game 4 assignment if the Dodgers are in a perilous position.
Houston, on the other hand, had a big decision to make with their Game 1 starter and quickly announced that Dallas Keuchel would get the nod. Verlander vs. Kershaw is the Game 1 head-to-head matchup that everyone drools over, but would it really help Houston win? Pitching Verlander on three days' rest wouldn't really change the team's other matchups for the better; it simply makes Dallas Keuchel's starts a day later. Pitchers tend to pitch worse on short rest, even the amazing ones, and starting the Series with Verlander-Keuchel vs. Keuchel-Verlander actually projected to cost the Astros 3 percentage points. Hinch will be second-guessed if Keuchel struggles in Game 1 and Verlander throws a stunner. He shouldn't be.
One advantage that Houston does have is that it is a less southpaw-heavy rotation than some teams, which does matter as the Dodgers had a 25-point OPS advantage vs. lefties in 2017, a flip of their script from 2016 when the team struggled against them. You could see some of this advantage this postseason, when L.A. beat up on Robbie Ray and Jose Quintana (and even postseason stalwart Jon Lester was erratic in his start). ZiPS projects this advantage to drop to 18 points, but that's enough to give Houston 4 percentage points versus if they had an all-lefty rotation. This team will take that.
