The Mariners have dominated these 10 hitters throughout their history

Chris Ianetta: 18-140, .129/.220/.193, 3 2B, 2 HR, 8 R, 11 RBI, 47 K

We kick off the next group with the short-lived stint as a Mariners catcher in Chris Ianetta. He had the 8th most ABs against the Mariners of anyteam he ever faced, but they had the most success against him of any team in baseball. He walked a bit, drove in 11 RBI, but struck out at an impressive 29.6% rate, over 2.5 times as often as he got a hit against the Mariners.

Josh Donaldson: 52-289, .180/.234/.367, 15 2B, 13 HR, 19 BB, 77 K

I think this one might make a lot of people happy, as he isn't the most likeable guy depending on who you root for (or against). His worst BA, worst OBP, and 3rd worst SLG are against the Mariners, who dominated Donaldson throughout his career. Funny enough, he actually hit well in Seattle, and hit a terrible .144/.182/.322 while playing in his home stadium against the Mariners.

Brian McRae: 38-204, .204/.276/.270, 7 2B, 2 HR, 22 RBI, 36 K

McRae was just worse against the Mariners (52 OPS+) than the Rays (56 OPS+), so they once again take the title as best against a player here. McRae had just 11 XBH against the Mariners and went an ugly 3 for 7 trying to steal bases. When your OPS+ is under 550, you know you're struggling. McRae just couldn't figure it out against Seattle over his ten-yea