Mariners come face-to-face with their worst nightmare in high-powered Cubs offense

Among the reasons that the Seattle Mariners are rolling into the weekend just one game over .500 is that they have not fared well against the league's elite offensive teams. They've dropped series to the New York Yankees, Arizona Diamondbacks, and Detroit Tigers.

Ready for the bad news, Mariners fans? Here it is: The Chicago Cubs are scoring runs at a higher clip than all three of those teams.

At an average of 5.36 runs per game, the Cubs' scoring rate is nearly a full run higher than Seattle's (4.34) and second only to the Los Angeles Dodgers (5.53). And with a league-high 12 games of at least 10 runs, there's an argument that Chicago's offense stands alone as the most purely explosive unit in the league.

The point, obviously, is that if the Mariners are going to walk out of Wrigley Field with a series win on Sunday, it will have to be because their arms rose to the challenge of shutting down Chicago's bats.

The Cubs pose a singular threat to the Mariners' run prevention machine

Mind you, it is not just the bats that make this Cubs offense so dangerous, though it is certainly not deficient in this respect. They rank sixth in batting average and fourth in slugging percentage. These guys are also hard to strike out, as they hold the seventh-lowest K% in the league.

Yet what really separates this Cubs offense from the pack is not only how much it tears up the basepaths, but how efficiently. We're talking 90 stolen bases against only 15 caught-stealings, making it no wonder that the Cubs have the highest success rate (35 percent) for scoring runners who get on base.

Nico Hoerner (14-for-17) and Kyle Tucker (18-for-19) will need to be kept in check when they get on base, but nobody is a bigger threat to take off than Pete Crow-Armstrong. Beyond being an elite defensive center fielder who's on track for 40 homers, he's also 23-for-26 in stealing bases.

It's important to know this end of the scouting report on the Cubs, because it's relevant to the scouting report on the other side: Of all the things the Mariners do well on defense, throwing out would-be base thieves is not one of them.

Cal Raleigh and Mitch Garver have a combined caught-stealing rate of 19 percent, well below the MLB average of 23 percent. Raleigh at least has a better-than-average pop time, but barely at 1.98 seconds to second base.

The best thing the Mariners can do, then, is simply keep Cubs hitters off the basepaths. And there is fortunately hope here which can be narrowed down to a single number: .284.

That is the on-base percentage that Seattle pitchers are allowing in June, and it's the fourth-lowest in the majors. George Kirby (.279) and Emerson Hancock (.250) have played a big role to this end, and both will start in this series. So will Logan Gilbert, who allowed only three hits and a walk in his return off the injured list on Monday.

If the pitching can't lead the way in this series, the Mariners are going to be in trouble.

Their offense has been on the fritz for the better part of the last two months, scoring only 3.6 runs per game dating back to May 3. It's also suffering a power outage in June. It has only 13 home runs overall and has gotten none from the overly aggressive Julio Rodríguez.

What will help is having Luke Raley activated off the injured list. But if the Mariners are forced into winning a slugfest against the Cubs, it'll probably go as well as the last time that happened. That was in Arizona against the D-backs, which resulted in a three-game sweep in which the M's got outscored 23-9.

In what is beginning to feel like an evergreen statement, the stakes are high for the Mariners. Though a 4-2 home stand last week got them back above .500, they enter Friday 5.0 games back of the Houston Astros in the AL West and 0.5 games behind the Boston Red Sox for the AL's third wild card.

With FanGraphs putting Seattle's playoff odds at basically 50-50, the last thing anyone wants is these deficits getting any bigger.

Game Times and Probable Pitchers for Mariners vs. Cubs, June 20-22

• Friday, June 20 at 11:20 a.m. PT: George Kirby vs. Matthew Boyd
• Saturday, June 21 at 11:20 a.m. PT: Emerson Hancock vs. Cade Horton
• Sunday, June 22 at 11:20 a.m. PT: Logan Gilbert vs. Colin Rea