This matchup pits great pitching against great hitting on both sides.
But some matchups look more one-sided than others and could cost either team another world championship. These matchups could be the keys to the entire series.
Here's a look at some of the matchup nightmares that could cost either team the World Series.
Note: All stats obtained from Baseball-Reference.com unless otherwise noted.
Koji Uehara has been dominant for the Red Sox throughout this year.
He finished the regular season with 21 saves, a 1.01 ERA and 101 strikeouts. In the postseason, he's pitched nine innings, given up one run and struck out 13. Uehara has been nearly unhittable and that's a potential nightmare for the Cardinals.
Carlos Beltran is the only player on the St. Louis roster who has an at-bat against Uehara, going 1-for-3. Outside of that, nobody else has ever faced the Red Sox closer.
That's an extreme disadvantage for the Cardinals, as they don't know what to expect when they first step in the box against him. They can look at tape all day long and learn his tendencies, but it's an entirely different story when they are finally facing him.
Uehara was named the MVP of the ALCS after throwing six innings and giving up no runs and no walks while striking out nine.
If a St. Louis batter is going to get to him, he is going to have to do it on the first pitch, where Uehara has thrown a fastball 17 of 31 times in the postseason, according to Brooksbaseball.net. When he has two strikes on a batter, regardless of how many balls in the count, Uehara is almost impossible to beat with 13 strikeouts and only one hit allowed.
When it comes to Uehara, there is nobody better on these two rosters to put the nail in the coffin.
The Red Sox were among the best base-stealing teams in baseball during the regular season, swiping 123 bags while being caught only 19 times. During the postseason, they've added 11 more thefts.
At the top of the order, it's been all about Jacoby Ellsbury and his 52 steals during the regular season to go with his six thefts during the postseason. He changes the game with his speed and it's shown in the playoffs.
During the regular season, Molina threw out 20 of 46 potential base stealers for a 43.5 percent success rate. Throughout most of his career, it's been the same, with Molina throwing out 236 of 530 runners attempting to steal.
Mike Axisa of CBS Sports sees this as the X-factor matchup of the World Series:
Molina's ability to shut down the running game is apparent in more ways than the caught-stealing numbers. Opponents have attempted only 416 stolen bases against the Cardinals since 2009, by far the lowest in baseball...Teams have more or less given up on trying to steal against St. Louis. Unless it's a critical situation, it's just not worth risking the base-runner because chances are Molina will throw you out.
Allen Craig is on the Cardinals' World Series roster, according to CBS Sports' Mike Axisa, and he presents a potential nightmare for the Red Sox.
On one hand, Craig has been out for six weeks with a foot injury. But as Bleacher Report MLB Lead Writer Zach Rymer says in his video preview, being healthy doesn't guarantee Craig will have his timing back:
If he doesn't have his timing back, he's not going to be able to help the Cardinals at all. But if he does have his timing back, then the Cardinals are getting back a guy who hit .315 with that .454 average with runners in scoring position. Their offense is only hitting .210 with .610 OPS in the postseason, so it could definitely use a boost.
In Game 1, Craig will face Jon Lester, and if Lester wants to ensure Craig is not a nightmare for him, he has to use his changeup.
According to Brooksbaseball.net, Craig has seen a changeup 111 times against a left-handed pitcher this season and has a .207 average against it. However, he also hit three of his 13 home runs off of changeups.
The changeup has been one of Lester's better pitches. He has thrown it 438 times to right-handed hitters who are hitting .214 off of it.
On the other hand, John Lackey would be better served to throw his slider in key situations against Craig. Lackey is allowing right-handed batters to hit .233 off of it while Craig is hitting .250 against sliders.
Craig will be the DH in Games 1 and 2, according to Axisa. Depending on how Craig performs in those two games will determine whether he'll start at first base when the World Series goes to St. Louis or if Matt Adams will continue to be the Cardinals' first baseman.
The Boston Red Sox may have finally solved their problems at third base by starting Xander Bogaerts in place of Will Middlebrooks.
Bogaerts has gone 3-for-6 in the playoffs with seven runs scored, three doubles and five walks. He's been good at the bottom of John Farrell's lineup.
Keeping Bogaerts from getting on base ahead of the likes of Jacoby Ellsbury and Shane Victorino is key for St. Louis pitchers. If he gets aboard, the Cardinals could be in trouble all series.
In Boston's ALCS-clinching win over Detroit in Game 6, Bogaerts played a huge role in the two innings where the Red Sox scored. In the fifth, he doubled and scored on an Ellsbury single with two outs. If Bogaerts hadn't doubled, the inning would have already been over and the Red Sox would have still been scoreless.
In the seventh inning, Bogaerts hung in against Max Scherzer to draw a walk and keep the Red Sox alive in their four-run inning. If Scherzer could have gotten Bogaerts out when he was ahead in the count, then Jose Iglesias likely would not have rushed trying to make a play on a grounder by Ellsbury.
Bogaerts' ability to turn the lineup over and ensure runners are on base for Ellsbury was a huge reason why the Red Sox beat the Tigers. If he does it again in the World Series, it's lights out for the Cardinals.
The middle of the batting order is usually the most dominant for any team, but that hasn't been the case for teams facing Michael Wacha this postseason.
In his three postseason appearances, Wacha has held the middle of opposing orders (hitters 3-6) to a combined 1-for-34 with 13 strikeouts, one walk (intentional) and one home run (Pedro Alvarez).
Against the Pirates in Game 4 of the NLDS, Wacha did his work against Andrew McCutchen, Justin Morneau, Marlon Byrd and Alvarez. Against the Dodgers in Game 2 of the NLCS, Wacha thwarted Adrian Gonzalez, Yasiel Puig, Juan Uribe and Skip Schumaker. In Game 6, Wacha owned Gonzalez, Hanley Ramirez, Andre Ethier and Puig.
The Dodgers were a combined 0-for-22 against Wacha with eight strikeouts. That's a big reason why he was named the NLCS MVP.
If Boston is going to get past Wacha in Game 2, and potentially again in Game 6, the middle of the Red Sox order has to produce.
No matter how great St. Louis' starting pitchers are in the World Series, the Cardinals won't be out of the woods in any game until the 27th out is made.
The Red Sox showed just how powerful their offense is with grand slams in the late innings of Games 2 and 6 of the ALCS to help propel them to the World Series.
Boston trailed both times, but relievers made mistakes both times as well. The first came mistake came from Detroit closer Joaquin Benoit in Game 2 against David Ortiz while the second was by Jose Veras to Shane Victorino.
During the regular season, the Red Sox hit 178 home runs, had 570 extra-base hits and drove in 819 runs. From the seventh through ninth innings, the Red Sox batted .253 with 57 home runs and 255 RBI. They also drew 222 walks, stole 44 bases and scored 267 runs.
They know it's not over until the final out. So should St. Louis.