FanPost Friday: Do the 2023 Seattle Mariners have the makings of the best pitching rotation of all time?

Hello and welcome back to FanPost Friday. The Mariners are fresh off a 4-game sweep of the woefully bad Oakland A’s and they will continue this beautiful homestand versus the Pirates and Yankees. Let’s keep raising that high-water mark of games above .500, Mariners!

Let’s go ahead and jump into this week’s theme: The Seattle Mariners pitching rotation is very good so far in 2023. How good, you ask?

That’s (counts out loud) 16(!) statistical categories that the Mariners rotation is currently the best at across Major League Baseball. This rotation could very easily end being the greatest Mariners starting rotation of all time, but how do/will they stack up versus the best rotations of time league-wide?

Some light Google research suggests that there is a widely-held consensus that the 1998 Atlanta Braves rotation is the best rotation of all-time, and it’s hard to argue otherwise (FanGraphs says “AHEM!” More on that later). Let’s take a look:

Baseball Reference

Look at future 2012 Mariner Kevin Millwood in his PRIME, dang.

Okay, so let’s look at some of the 2023 Mariners stats Alex Mayer is talking about.

Baseball Reference

So, obviously it’s hard to compare any counting stats between the two since one is a full season and other is two months of games, but the rate stats are...surprisingly comparable and the Mariners SO/9 rates are pretty outstanding in comparison, although you do have to take the sample size into consideration and the fact that baseball in 2023 is very different than it was in 1998 in terms of strike out rates and totals in general (and in many, many other ways). Still! I was surprised at how not-far-off the 2023 Mariner are right now from the gold standard 1998 Atlanta Braves.

Here is some further stats-diving on the 2023 Mariners, as I asked (begged) the more stats-savvy writers on the LL staff to help me out on this. The most excellent Jake Mailhot shared this FanGraphs Leaderboard that has starting rotations sorted by league-adjusted ERA. Jake says, “There have been 1528 team seasons since 1969 (the year the mound was lowered). The Mariners currently have the 16th best league adjusted FIP and the 19th best league-adjusted K/BB ratio. Pretty good.”

Just for another comparison, let’s take a look at arguably the best Mariners rotation until right now, the 2001 Mariners (who are ranked at #136 on that FG leaderboard Jake shared).

Baseball Reference

This is one of many reasons that the 2001 Mariners are endlessly fascinating to me. As many of us remember, the 2001 Mariners pitching staff weren’t the over-powering type, besides young Freddy Garcia. They were just all-around GOOD, perhaps a bit lucky, had a lights-out bullpen, and were also buoyed by an incredibly productive Mariners offense. But, if pitcher W-L records are your kink, the 2001 Mariners and 1998 Braves will certainly have you fanning yourself.

Anyways, those LLers who are very stat-inclined, please take this as your opportunity to dive further into the 2023 Mariners rotation and make some bold claims in the comments:

1. Which 2023 Mariners starter will finish with the best SO/9 rate?
2. Who will finish with the lowest BB/9 rate?
3. Rank the 5 starters by their strike out totals, highest to lowest

Have a great Memorial Day weekend! Hopefully you get to have some restful and fun times as you see fit. Go Mariners!