The Milwaukee Brewers eye a commanding 3-1 lead over the Los Angeles Dodgers in the National League Championship Series, and the Boston Red Sox visit the Houston Astros with their American League Championship Series tied at 1. In other words: In the Senior Circuit, a World Series spot could be all but locked up nine innings from now at Dodger Stadium, while in the Junior Circuit, momentum is on the line at Minute Maid Park.

MLB Postseason on ESPN Radio From the first pitch of every series to the last out of Game 7, you can catch the entire MLB postseason on ESPN Radio. Listen »

The most important thing of the day: With Rick Porcello again pitching out of Boston's bullpen, Nathan Eovaldi gets another Game 3 start in hostile territory. In the American League Division Series, he pitched the Red Sox to a laugher in the Bronx. Now, Boston's fireballing trade-deadline acquisition will face the defending-champion Astros on their home turf. Will manager Alex Cora's division series plan pan out again in Round 2, or will Houston take another step toward a repeat trip to the Fall Classic?

American League Championship Series Game 3: Boston Red Sox at Houston Astros

Nathan Eovaldi (6-7, 3.81 ERA) vs. Dallas Keuchel (12-11, 3.74 ERA), 5:09 p.m. ET, TBS and ESPN Radio

The stakes: David Price (still winless in 11 postseason starts) didn't get the W in Game 2, but his Red Sox did -- denying the Astros a sweep at Fenway Park. But the split allows Houston to potentially close out the ALCS at home and send the Green Monster into hibernation for the winter. Will the series return to Boston on Saturday, or will the defending world champs put the Sox away this week at Minute Maid Park?

If the Astros win: The Astros were far tougher on the road during the regular season, but in October, their home-field advantage has been significant. Dating back to last year's ALDS, when they beat Boston twice in Houston, the Astros are 10-1 at home. Their lone loss was Game 4 of last year's World Series against the Dodgers. If they improve to 11-1, this stat will loom even larger: When a best-of-seven series is tied at 1, the Game 3 victor has gone on to win the series 69 percent of the time (63-28).

If the Red Sox win: Their strategy to pitch Rick Porcello in relief will have paid off again. Porcello was originally slated to pitch Game 3 in the ALDS against the Yankees and would have been well-rested for a potential Game 3 outing in the ALCS against the Astros. But before he could start in either series, he was called in from the bullpen with eighth-inning leads, helping to preserve victories. Eovaldi gets the Game 3 nod again; last time out, he went seven strong in the Bronx, allowing just one run in a 16-1 Red Sox rout.

One key stat to know: 9.15. That's Keuchel's career ERA against the Sox. The wrinkle? Those are regular-season numbers, which certainly didn't mean much last October when Keuchel beat Boston in Game 2 of the ALDS, allowing one run and striking out seven in 5 2/3 innings.

The matchup that matters most: J.D. Martinez vs. Houston. Astros pitchers have so far stifled Martinez, who is 0-for-7 in the series with three strikeouts and a harmless walk. And while Martinez holds no ill will toward the team that drafted him and for whom he struggled over his first three seasons before being released in 2014, he has been a totally different player since. Breaking out on his former team's home turf might not be personal for the AL's RBI champ, but it sure would be sweet for the Sox.

The prediction: It's hard to pick against Keuchel in what could be his final start in an Astros uniform. Of course, if he wins, that makes it more likely he starts again later in the postseason. Let's go with this: The Red Sox pitch to Alex Bregman and he makes good on his Instagram post with a home run ... or two. Astros 5, Red Sox 4 -- David Schoenfield, ESPN.com

National League Championship Series Game 4: Milwaukee Brewers at Los Angeles Dodgers

Gio Gonzalez (10-11, 4.21 ERA) vs. Rich Hill (11-5, 3.66 ERA), 9:09 p.m. ET, FS1 and ESPN Radio

The stakes: It's about as close as it gets to a do-or-die game without technically being a do-or-die game. Let's just say the Dodgers had better win.

If the Brewers win: They're one victory from reaching their first World Series since the 1982 Brew Crew of Robin Yount, Gorman Thomas and Rollie Fingers.

If the Dodgers win: We're back to square one with an even series, Milwaukee holding home-field advantage and L.A. (presumably) handing the ball to Clayton Kershaw.

One key stat to know: Since the LCS went to a best-of-seven format in 1985, road teams that have won Game 3 of a best-of-seven series that was tied 1-1 have gone on to win the series 77 percent of the time (17-5). So history already is squarely on the Brewers' side.

The matchup that matters most: Rich Hill vs. top of Brewers order. The trio of Lorenzo Cain, Christian Yelich and Ryan Braun has had some success against the Dodgers' Game 4 starter, albeit in limited at-bats. Cain, Yelich and Braun are a combined 9-for-25 against Hill with four doubles, one triple and a slash line of .360/.407/.600. Of course, they each might get no more than two cracks at Hill, so they had better strike early. And overall, Hill had a 1.50 ERA in two starts against Milwaukee this season.

The prediction: As good as Milwaukee's pitching has been in the series, this Dodgers lineup is too good to stay quiet for long, and I think this is the game in which L.A.'s bats finally break out. Manny Machado hit a laser-beam home run against Gio Gonzalez in Game 1, and he's the guy I'm looking to have a big game again this time around. Dodgers 6, Brewers 3 -- Dan Mullen, ESPN.com