One seems a foregone conclusion. The other looks like it’s happening a week too early.

Such is life in the Class B football playoffs. Mountain Valley is the team who would be king in the West, while there just aren’t enough crowns to satisfy the roster of challengers in the East.

Having outscored its regular-season opponents by an average score of 50-6, Mountain Valley begins the finishing kick of its race to a fourth regional title in six years by hosting playoff newcomer Falmouth in tonight’s 7 p.m. semifinal at Hosmer Field in Rumford.

Thirty minutes down the highway but sequestered at the other end of the state bracket, Eastern top seed Leavitt will try to hold up its half of a tri-county state championship in a 7 p.m. showdown with Morse at Libby Field in Turner.

Here’s a closer look at the local matchups:

#4-Falmouth (6-3) at #1-Mtn. Valley (9-0)

The Yachtsmen fared better than most against Mountain Valley in their regular-season opportunity, dropping a 42-7 decision that was much more competitive between the lines than on the scoreboard.

Mountain Valley didn’t take the lead for good until midway through the second quarter. Then a flurry of Falmouth turnovers and big plays by the Falcons restored business as usual.

Falmouth stayed in the game by loading up against bruising MV runners Justin Staires and Matt Laubauskas and unleashing its own athletic quarterback, Stefano Mancini, on a variety of bootlegs and rollouts.

Competing with the Falcons means choosing your poison, however, and both sophomore QB Cam Kaubris and Staires were successful through the air against Falmouth’s preoccupied secondary.

Travis Ruff’s hands fueled the Falcons on both sides of the line of scrimmage.

It was Falmouth’s only loss in its final five games en route to the Yachtsmen’s first-ever postseason appearance. Sam Dunwoody, Caleb Bowden and Kris Floridino are threats to move the chains and play keepaway, which might be the visitors’ only chance to spring an upset for the ages. Chip Clement is Mancini’s top target.

Cape Elizabeth (8-1) and York (6-3) meet in the other semifinal.

#5-Morse (6-2) at #1-Leavitt (8-1)

The Hornets are a top seed for the first time in a decade, but it’s the Shipbuilders who enter the Eastern Class B playoffs ballyhooed as the hottest team in the state.

Disheartened by early-season losses to Waterville and Mount Desert Island and trailing Maranacook by two touchdowns with a quarter to play in Week 3, Morse rallied for an overtime victory and hasn’t let off the accelerator since.

Three weeks later, Morse knocked Leavitt from the unbeaten ranks when Alex Kee picked off a pass inside the 5-yard line in the final minute to seal a 19-12 victory. Nobody has scored a point against the Shipbuilders since, with Morse shutting out defending state champion Gardiner, Oak Hill and playoff foe Winslow by a combined score of 86-0.

Morse has found ways to move the football in the absence of star fullback Pat Wolfe, who went down with an ankle injury in the Gardiner game. Wolfe riddled Leavitt for 207 yards.

Jay Cavanaugh, Kee and Tyler Russell have kept the ground game churning. Cavanaugh and Karl Nygaard are the heart of the defense at linebacker and defensive tackle, respectively.

Leavitt struggled past Oak Hill, 21-18, in the quarterfinals. Few teams have been able to counter the speed and strength of Tyler Green and Josh Strickland, who have accounted for more than 2,000 yards from scrimmage. QB Eric Theiss is a threat with the deep ball.

Phillip Russell, Kolby Youland and Drake McBreiarty highlight the Hornets’ defense. McBreiarty’s late-game interception put the Hornets in position to tie or win the previous meeting until the ill-fated finish.

In the other Eastern B semifinal, Gardiner (6-2) and Mount Desert Island (7-1) meet for the first time ever in Bar Harbor. Each won by a point last week, with MDI staving off Waterville’s late two-point conversion in a 28-27 triumph and Gardiner denying Hampden, 21-20.