More on drag coefficients. Graph shows fly ball distance for EV=104 mph, LA=25-30 deg plotted versus Cd, all monthly averages. Very clear correlation.

See sabr.org/all-time-era... for the full list.

SABR has announced their All-Time Eras Teams for the period 1920-1946, divided into 1st, 2nd, and 3rd teams. Ted Williams does not appear on any of those teams. Hard to believe that he is not among top 9 outfielders of that era. I conclude that I should not take these lists seriously.

Cd=drag coefficient, a property of the baseball that affects the "carry" of the ball through the air. Large Cd means more air resistance and less carry.

One more: Weekly averages at Tropicana Field, sorted by years. That is the best case scenario for constant atmospheric effects.

Here are weekly averages:

Here you are...

You can see from the daily (or weekly) trend of Cd that after an initial period when Cd was pretty stable, it has been on a downward trend since about day 112 (April 22). So the standard deviation is increasing over time.

The plot shows the day-to-day scatter of daily Cd averages.

Here is plot of average daily Cd standard deviation

I suppose so. Anyway you gave the numbers.

Much more variation this year than previous. Below are year, mean and std dev of daily Cd: 2017 0.3348 0.0058 2018 0.3371 0.0044 2019 0.3278 0.0039 2020 0.3404 0.0057 2021 0.3410 0.0053 2022 0.3468 0.0045 2023 0.3416 0.0042 2024 0.3433 0.0047 2025 0.3516 0.0046 2026 0.3464 0.0087

Re a plutonium bomb, this article is worth reading: thebulletin.org/2026/04/miss...

There is no one in the Trump administration qualified to negotiate with the Iranians. Especially on the plutonium issue. #Iran #USA

Actually I don't believe humidity plays a large role. Huge swings in the relative humidity at typical game temperatures result in only small changes in the air density, which is what matters. I agree about wind, but make it 4d (3d+time). @weatherapplied.com knows how to do this.

To get some idea of the relationship between Cd and HR probability (pHR), see the plot I last updated in August 2024, showing relationship between pHR (controlling for EV and LA) and "density-corrected" Cd (monthly averages). The correlation is quite clear. Need to update with 2025,2026.

Yes, that is what I mean by "gametime temperature".

One additional point I should make: The kind of daily trends we are now seeing have not been seen in previous years, using the same algorithm for obtaining Cd (including gameime temperature but not including wind).

My calculations use gametime temperature. It would be better to use actual temperature in real time, which is known but not publicly available. I don't know what is used by Statcast. Regarding wind, I completely agree that neither my results nor Statcast's take wind into account.

To learn more about this topic, I highly recommend Barbara Tuchman's book "The Zimmermann Telegram". Particularly interesting is how the British knew about it well before the US and didn't reveal it because they didn't want the Germans to know they had cracked their code.

What would be useful is an analysis of home run rates, controlling for EV and LA, and how they correlate with Cd. I have done such an analysis before but not for 2026. Simply doing a monthly analysis should be revealing.

Just to make sure there's no confusion, both Cd and Cl should be independent of air density since it has already been factored out. My comparing the trends of both was simply to be sure I got the air density correct. My calculation was based on gametime temperature.

Here's what I have found. Top plot is drag Cd, bottom plot is lift Cl. Cd shows steady decrease by nearly 10% since start of season. Cl does not. So it's not simply an air density effect, which should affect both quantities. Next step would be to see whether HR rates track with Cd. Later.

Just started my own analysis of drag coefficients. Will take a bit of time as I need to first download all of the pitch data. Stay tuned.

My 1st inclination would be to question the data. The amount of variation this year on the daily average is much greater than in any of the other years. I haven't been doing my own tracking this year. Perhaps I should.

This.

My latest: Trump’s Failed War against Iran open.substack.com/pub/michaelm...

I suppose that is true. However, many have aged well and still have relevance today (just my opinion, of course).

Unfortunately I'll not be attending this year due to a conflict. But I encourage all my baseball followers out there to attend. Saberseminar has always been one of the great forums for learning about the latest baseball research and connecting with other like-minded people. Do not miss it!

Actually Rod Serling was very clever and effective at using the supernatural to disguise his social commentary. That's one of the reasons I consider The Twilight Zone to be one of the best TV shows of all time.

Know what TV show actually wouldn’t get made today? The Twilight Zone. Half of these fuckin’ episodes are about fascism.

I'm glad to see that @ernestmoniz.bsky.social has been making the rounds on various talk shows in the past several days, presenting his views on the current MOU with Iran and comparing it with the process in 2015 in which he played a key role and which led to the JCPOA.

I found indirect support for that idea a few years ago when I showed that the variation in drag was significantly reduced in closed stadiums relative to open ones. See www.baseballprospectus.com/news/article...

Benetti is truly one of the best.

They tried to hide but I got em anyway

Is this some kind of metaphor?

Great story about Charlie Y oung: uiaa.org/2026/06/11/p...

Some time ago, I got interested in the spin decay time of a baseball. Using well-documented data from golf and scaling arguments, I found that the decay time constant (1/e time) is of order 25 sec at 100 mph and even longer at slower speeds. baseball.physics.illinois.edu/spindown.pdf.

Thanks for posting.

Your colleague @alexspeier.bsky.social wrote a nice article about Ted's red seat HR a few years ago.

This is terrible news. Gordon Wood is my favorite historian of the Founding Era. I've read most of his books and a number of his essays. May his memory be a blessing.

How about having him start by hitting off a tee. Then bunt of pitching machine.

private work with the pitching machine. From what I see, his hand-eye is ok, but I'm not sure he really tracks the ball or even tries to. My plan is to work on making contact with no swing. Anyone got more ideas? 2/2

Is this big? Because it seems big. www.notus.org/2026-electio...

One of Yogi’s last acts was to say MLB & sports in general had to get right with LGBTQ people

Here a a picture of Wilson Compton, former president of WSU and brother of physicist and Nobel Laureate Arthur Compton, who first unraveled the secrets of Compton scattering from the electron. I spent much of my career in nuclear physics ( pre baseball) using Co.pton scattering ...

Margaret Chase Smith’s speech may be from a different era, but it is so insightful. It absolutely could have been written about the current state of politics and its detrimental impact on the Country and citizens.

A sign outside the baseball stadium at WSU.

The experiment and Standard Model calculation agree to within 0.5 standard deviations, implying no evidence for new physics beyond the Standard Model.