Carlos Pena: 64-308, .208/.307/.360, 15 2B, 10 HR, 26 RBI, 94 K
Now we get into it. The people who went their entire and were just never able to figure it out against the Mariners. We start off with Pena, who amassed half a season's worth of ABs against the Mariners. It may look like he did alright with a .360 SLG, but when you realize that 25 of his 64 hits were XBH, there really wasn't a lot of damage done, especially with only 26 RBI. That 30% K rate is nice, also.
Mickey Tettleton: 87-392, .222/.323/.395, 11 2B, 17 HR, 51 R, 119 K
Speaking of a 30% K rate, Tettleton did the same in 100 more ABs. He scored a fair amount of runs for struggling to get on base, but didn't do much else. It's worth noting on some of these "older" players that these numbers are based on averages that were a lot higher than we see in today's game, so it's more in line with a .205/.305 slash line. I'll always remember Tettleton for his crazy stance at the plate, and it seems like it wasn't able to distract the Mariners at all.
Kurt Suzuki: 91-414, .220/.273/.350, 33 XBH, 37 R, 51 K
The most recent career player on this list saw the Mariners a lot, put the ball in play a lot, but it never amounted to much. It's actually impressive that he had such a low K rate, with just 51 in 400+ ABs. Limiting him to 37 R is just as impressive too, as whenever Suzuki was involved with a play, it ended up going in the Mariners favor.
Kenny Lofton: 102-422, .242/.319/.334, 21 XBH, 67 R, 52 K
I had to save this one for the end, just because Lofton was one of my favorite players, and easily one of my favorite non-Mariners as a kid. He stole bases like a madman and ended up a career .299/.372/.423 hitter, but the Mariners held him in check in over 100 games. It's even more impressive when you realize that out of the top 5 teams to succeed against Lofton (keeping him to a sub .270 BA) the Mariners were the only ones to play him more than 45 games.
Not a ton of huge names on this list, but still a good mix of great and darn good players. It's nice knowing that there are some players the Mariners were able to dominate at the plate throughout their careers.