The answer to this question would ease the minds of owners all across the fantasy universe [insert Avengers joke here]. Chris Archer hasn’t performed well enough to warrant selection in the same stratosphere as his preseason ADP. His strikeout rate is down, walks are up, and he’s getting hit harder than he ever has. This has created the notion that the Rays’ ace is declining, simply because he is approaching the age of 30 with numbers that don’t represent his past performance.

Assuming any given player follows a smoothed performance curve through their careers is incorrect. Curves representing how players age are the compilation of aggregate data points suggesting the average peak is right around 27 years old. Players can peak before or after that mark and the trend line can still retain its shape.

A mental exercise to perform is considering whether you believe general aging curves do in fact hold value. If your answer is yes – which it should be – then consider whether Archer has declined at an unexpected rate; more than a general aging curve would have suggested. Based on projections, the answer to this question should also be yes, even if you were the “low man” on Archer coming into the season.

This leaves three possibilities: further decline, stabilization, or improvement. Option number three is where most should guess Archer ends up, especially if you think he has declined more than expected through 11 starts. Thankfully, this is the logic I follow as well. How much room there if for improvement in Archer’s game is the big question.

Above is a simple look at Archer’s year-over-year splits against the handedness of hitter with a natural advantage versus his heavy fastball-slider combination. Archer’s effectiveness versus right-handed hitters remains stable when comparing 2017 to 2018, making the culprit behind this discrepancy in lefty effectiveness a good starting point. With the baseline knowledge that Archer mixes in his changeup only to left-handed hitters, my initial thought was this offering may have changed compared to last year. This brings us to a bit of a rabbit hole.

Just over a month ago, Rays Manager Kevin Cash said he didn’t agree with the concept that Archer needed to throw his changeup more to left-handed hitters. This theme has been commonly discussed with Archer for an extended period of time, with outlets pondering how Archer could be an ace if he didn’t have an effective third pitch (example one, example two).

So what happened? Archer started throwing his changeup more – contrary to Cash’s belief that Archer didn’t need to – increasing the pitch’s usage six percent to left-handed hitters from 2017 to 2018.

How Archer was using the pitch changed slightly as well. Keep an eye on all of the two-strike counts in the bottom left of the GIF below. The blue dot represents Archer’s changeup usage.

*Count breakdown versus left-handed hitters

In 2018, Archer has been turning to his changeup more, and turning to it in two-strike counts, providing some context that Archer has become more confident in the pitch itself.

We’re not only looking at more changeup usage and different changeup usage, but we’re actually looking at a slightly altered pitch as well, which brings us back to aging curves. Presented below is a pitcher-specific aging curve for particular stats, showing the deviation away from a player’s average after their age 27 season.

Velocity decrease is the most visually striking in the plot above, and most applicable given how important a component it is to changeup effectiveness. Many anthologies exist breaking down the relationship between velocity differentials of fastball-changeup combinations (like this one), with the resounding point suggesting that a 7-10 mph difference between the two pitches is ideal. A larger differential (closer to 10 mph), generally results in more whiffs, while a small differential (7 mph), generally leads to more groundballs.

This effect is represented well when examining Archer’s fastball-changeup relationship from 2017 to 2018. Abiding by the aging curve, Archer has lost roughly .4 mph on his fastball (depending on your site of choice, mine is Baseball Savant), but gained just over 2 mph of velocity on his changeup. This has changed his fastball-changeup differential from 9.8 mph in 2017 to 7.2 mph. To confirm the world is indeed round – sorry, Kyrie – Archer’s changeup has become slightly more of a ground-ball pitch, with his groundball to fly ball ratio on his changeup rising from 3.4 in 2017 to 5.0 so far in 2018.

While this gives some context to the drop in whiffs versus left-handed hitters, it fails to explain why the overall performance of Archer has been so poor.

If his changeup is merely different and not less effective, then the issue must be embedded within either his fastball or slider. Fangraphs contests the issue is within both, grading each out as average to below average pitches this year based purely on results, both with a noticeable decrease from 2017 (per Fangraphs pitch values/100).

Yet the difference for each of Archer’s fastball and slider are more subtle than worrisome. His fastball location to left-handed hitters is slightly elevated this year, bordering on out of the zone, which could be a reason for the pitch’s drop in whiff rate (down 6 percent from 2017 to 2018). While the pitch’s slight drop in velocity helps validate proper aging for Archer, as we noted above, the bigger differential was in Archer’s changeup velocity. Archer’s fastball velocity is still above the 90th percentile in the league.

His slider has become a slightly flatter pitch too, with Baseball Prospectus’ Pitch F/X leaderboard showing the pitch has more horizontal movement than it had in the past and less vertical drop on average. This could be Archer manipulating the pitch in an altered way, but with a stable whiff per swing rate from 2017 to 2018, its effectiveness remains largely in tact.

Is there any merit to the substance of a pitch remaining stable, but the result deteriorating? Is there any chance that Archer using his improved changeup more to left-handed hitters has hurt his slider’s effectiveness? This seems to be a weird way to cite why Archer’s slider is getting beat up by left-handed hitters, but it’s a hypothesis nonetheless.

  • 2018 AVG/SLG versus Archer’s slider (LHH)
    • .296/.568
  • 2017 AVG/SLG versus Archer’s slider (LHH)
    • .214/.332

Archer, with an improved changeup, has actually become less effective with the pitch that has carried him through the better part of four seasons. Whether the two are tied together, or merely coincidences, might be the key to understanding whether improvement from his hard decline is in store.

The Player Rater believes Archer is still a top-15 starting pitcher, with a strong finish in store; one that resembles the years where his changeup was more of an afterthought and his slider reigned supreme. Archer may be declining, but the substance of his repertoire is still in tact, which provides optimism 2018 can still be turned around.


On Twitter, I do not decline – @LanceBrozdow

Podcast #1 – Ralph and I talk prospects – Razzball Prospect Podcast (Archive)

Podcast #2 – I talk about pitchers – TwoStrikeApproach (Spotify, Apple Podcasts)

  1. coacher says:

    I’m just glad I don’t own Archer. Good write-up, though.

    I have 2 OF spots and a U to fill. I have J.Bruce, Buxton, and Mac Williamson. I also have some U options – R.Guzman and Pedroia.

    Who would be the 3? Who goes to the bench and who gets dropped?

    • Lance

      Lance says:


      I would recommend playing matchups with the 2 OF and 1 UTIL spot, but in terms of who the best three are rest of season that fill those spots for you, I’d take Bruce, Buxton, and Pedroia.

      Might be interesting to ride out Guzman and Williamson for the time being though (over Buxton and Pedroia, before they both get it going.

  2. Good stuff. I know Jeff Zimmerman found that his fastball was getting hit much harder when he was putting it in the zone, and that alone could explain the urge to throw more changeups in general by Archer. It seems to be a conflux of things, just like you mentioned and one that’s difficult to truly project.

    For now, he’s still performing well against Right-handed heavy lineups like his start against the Angels, but it’s hard to trust him otherwise. Sad too because I really like the guy as a person and as a pitcher.

    • Lance

      Lance says:

      @Van Lee:
      Exactly! I feel in a lot of scenarios during pitcher evaluation, I’m able to come to some conclusion (even if it’s flawed) as to what might need to change. But with Archer in this case, I found myself irrationally thinking his slider will just come back to LHH.

      He’s in a weird spot, he might in fact be declining, but I think there is a stability in an arm like this that is much better than average.

      Love him as a person and pitcher as well, he’s a smart guy, I think he has a much better understanding of the game and the community around it than others.

  3. LadyScorpio says:

    Good article! I wanted Archer on my team 2 years ago, but that was then. I’ve never been fortunate (or unfortunate) enough to draft him. I hope he can turn things around, though. Cause when he’s on, he’s ON!!

    This year, I drafted Ohtani, Berrios, Weaver, A. Reyes, Wood & Taillon. I dropped Weaver for Pivetta then dropped him for Buehler. I also dropped Taillon for Happ. My lineup is now Ohtani, Berrios, A. Reyes, Cahill, Buehler & Wood. I’m quite pleased and hope that they’ll all do well come the end of the season. I’m in a 10 team, roto, 6×6, keeper league and I’d been bottom feeding in the standings until this weekend. My offense and pitching are finally coming together. However, once Acuna returns from the DL, I’ll have to drop a pitcher. Whom would you recommend?

    • Lance

      Lance says:

      Agree! He’s fun to watch when he’s on.

      You have time to wait and see what happens without Acuna, I would be stunned if he’s out for less than 15 days. In that time, a lot can change.

      But I think Cahill is an aberration, so it’s him for now for me.

  4. jose H. says:

    What is your opinion of LHP Caleb Ferguson (21)?
    I just started following him after seem what he did on his AAA debut:

    Player IP H R ER BB SO HR ERA
    Caleb Ferguson 5.0 3 0 0 3 10 0 0.00

    • Lance

      Lance says:

      @jose H.:
      I can’t say I know too much about him honestly. Wouldn’t be overly excited as he doesn’t really grade out as having anything notable outside of purely results (which is objectively a good thing), but that’s a nice AAA debut for sure.

      Main issue is where he fits, especially if LAD sees him as a starting pitcher. Dennis Santana and others are probably ahead of him in terms of their upside, which hurts his value a bit.

      Results have been there, just not sure if it’s worth giving more than a passing thought.

  5. Fred Garvin MP says:

    An enjoyable thought provoking read as usual, Lance. Archer’s trouble can be traced, in my opinion, to one major factor: command.

    In a recent metric developed by Eno Sarris and others to calculate command, he was bottom 15 or so. I’ve watched plenty of his starts this year, and he has a considerable amount of trouble hitting spots. Even today, he got 3 k’s on sliders at the top of the zone.

    The heatmap of sliders to LHB this year is a roadmap of where you don’t want to throw a slider to a LHB.

    As much as xFIP wishes to normalize HR/FB rate, the fact is that some pitchers are considerably more prone to HR’s than others. A guy that throws his slider a ton and has trouble commanding it, is one of them.

    Overall, I think he’s a 3.70+ ERA guy with a WHIP a little over 1.20 and a healthy amount of strikeouts with a weak offense to support him.

    • Lance

      Lance says:

      @Fred Garvin MP:
      Thanks for the read Fred, you make some really interesting points.

      I love Eno’s new statistic, I think it gives us a great baseline of understanding who is a command pitcher and who isn’t, but I’m sure Eno himself would even say not to completely rely on one thing.

      In terms of Archer, while we can say his command is poor, the reality is that his command may always have been poor. I would be really interested to see where Archer sat on Eno’s stat for 2017 and 2016. Is there is a large difference between his rank then and now?

      I say this because bringing up his slider location v LHH is important, it’s something I looked at as well, but it’s actually been relatively consistent year over year. If you look at it in 2017 and 2016, it’s essentially the same, in-zone location as it is now. Sure, maybe it’s not where you want to throw the pitch, but the reality might be that he was successful throwing the pitch there for all these years, why all the sudden now is everything deteriorating?

      This is the question I unfortunately don’t have an answer to either. The funny thing is that I actually agree with your 3.7, 1.2 WHIP, heavy Ks projection. So even while we might disagree on one point, the result is our agreement that Archer is well above average arm in terms of production.

  6. MW says:

    Thanks for this excellent analysis! Currently have him on my team and waiting to see what happens.

    • Lance

      Lance says:


  7. Milo says:

    Thanks for the article! I got frustrated with him and sent some offers out now that he had a couple of good performances. One offer on the table is Archer and T. Shaw for McCullers.

    Context: Its a 10 team 6 x 6 league so replacement level hitting is fairly available on FA (plus, I have Arenado, Eugenio and Devers at 3B in addition to Shaw).

    Pull the trigger?

    • Lance

      Lance says:

      So it sounds like it’s essentially McCullerrs for Archer? I still want to lean Archer, but it’s pretty dam close for me. Can’t fault you one way or the other.

  8. LennyDykstraIsJustMisunderstood says:

    good write up; i have archer as well too much potential to bail but dissappointing so far.

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