Here are the reasons the Mariners are struggling at the plate in the second half

Things aren't looking great for Seattle. While the 11-15 record in the second half isn't the worst stretch of baseball ever played (tied with the Phillies & Braves), it's made worse by the fact that with a 16-10 record in the same span, the Astros have surged past the Mariners to give themselves a comfortable lead in the AL West. At the time of writing, the Mariners have just a 15.8% chance to win the division and a slim 21.7% chance to make the postseason. So what is actually going wrong in the second half?

The biggest problem remains the lineup. Despite a few rough outings by the rotation recently (Luis Castillo vs. Pirates, George Kirby vs. Tigers), the pitching staff is still excellent, posting a combined ERA of 3.63, eighth best in MLB. On the other hand, Seattle's second-half OPS of .660 is 28th in MLB ahead of just the Tigers and White Sox, neither of which are postseason contenders. The team batting average of .201 is by far the worst in MLB, trailing even the disastrous White Sox. While they've somehow managed to score more runs than the Astros by one during this 26-game stretch, the number is skewed by the four games in which they scored 10+ runs.

There are a few specific things the Mariners have struggled with at the plate. First and foremost, their combined OPS against lefty pitching is a paltry .576, far worse than the already subpar .709 OPS against right-handed pitching. Leading the race to the bottom are Justin Turner (22 PA, .439 OPS), Dylan Moore (37 PA, .520 OPS), and Victor Robles (.565 OPS). Jorge Polanco, who is having his own second-half renaissance, has been hitting lefties well, posting an OPS of .824 against them.

Second, they've been one of the worst teams against any sort of pitch movement. Their .520 OPS against curveballs, sliders, and sweepers is the second-worst in MLB, ahead of just the Reds. Their .449 OPS against the slider is especially concerning given how popular it has become in recent years. Dylan Moore (26 PA, .323 OPS) and Cal Raleigh (21 PA, .381 OPS) have struggled the most against breaking balls while Randy Arozarena has made out okay with a .743 OPS.

In a similar vein, the Mariners are actually one of the best at hitting the four-seam fastball (.797 OPS, 11th in MLB), but their .201 average against cutters and sinkers brings them down yet again. However, the plate discipline is pretty good against moving fastballs as the team is walking more than they are striking out against them (13.6% BB, 12.8% K), allowing them to still be somewhat productive.

To cap things off, while the Mariners have just one qualified player with a second-half OPS >.800 in Jorge Polanco, the Astros have four: Jeremy Peña (.809), Alex Bregman (.887), Yainer Diaz (.914), and Yordan Alvarez (1.069). Without major improvements to the Mariners' hitting approach, things look more and more grim for the team's postseason aspirations with each passing day.