Yamamoto's Notebook Is the NLCS Mystery Nobody Can Solve — Not Even His Catcher

Yamamoto's notebook, explained in one sentence

Los Angeles Dodgers pitcher Yoshinobu Yamamoto writes by hand in a black notebook in the dugout between innings — and even his catcher, Will Smith, says he does not know exactly what is inside it. That simple mystery, resurfaced hours before Game 2 of the National League Championship Series, is why the notebook is going viral again.

Every postseason start brings the same shot: Yamamoto off the mound, pen in hand, scribbling while most pitchers are reaching for a tablet. Fans want to know what he is writing. Teammates, it turns out, are not much closer to an answer than the rest of us — and that is exactly what made Smith's comments on Monday so shareable.

What happened?

Ahead of Yamamoto's Game 2 start against the Milwaukee Brewers on Monday, Smith was asked about the notebook Yamamoto has regularly been seen using since joining the Dodgers two years ago. Smith said the two talk constantly, so the notes are probably the same things they discuss, but he does not actually know the contents.

The exchange got funnier from there. Asked whether Yamamoto ever writes a boast after a strikeout, Smith laughed it off and said no. Dodgers Nation clipped the moment on October 12, and both the New York Post and USA Today For The Win picked up the story within hours — turning a familiar dugout habit into the talking point of the day.

Why is it blowing up?

First, timing. A notebook is a curiosity in the regular season. In the NLCS, with every pitch dissected, it becomes a potential edge — and everyone wants to decode it.

Second, the contrast. Modern dugouts run on video and iPads. Yamamoto runs on paper. That old-school image cuts through a feed full of identical highlights because it raises a real question: what does a top postseason pitcher notice in the moment that a screen does not capture for him?

Third, the mystery held. Smith did not reveal a secret system, a code, or a joke. He confirmed there is no trash-talk diary, and then left the actual pages closed. A mystery that survives a direct question travels further than one that gets solved.

Key facts about Yamamoto's notebook

He writes between innings. Both the Post and For The Win describe Yamamoto taking handwritten notes in the dugout during his starts, a habit viewers have spotted regularly over his two seasons with Los Angeles.

It may be built around the strike zone. Former professional pitcher Robby Rowland, cited by both outlets, believes the notebook contains drawings of the strike zone, with pitches circled and numbered — possibly marking which pitches hitters swung at.

Writing by hand may be the point. Rowland's explanation, again reported by both outlets, is that putting pitches on paper helps fix them in memory more effectively than tapping through an iPad.

It doubles as a scouting report. Reporting by Tom Verducci of Sports Illustrated, cited by both the Post and For The Win, described Yamamoto sitting with his interpreter and pitching coach Mark Prior between innings, opening the notebook to review his own scouting notes and prepare for the next three or four hitters.

His catcher has not peeked. Smith's Monday comments are the freshest confirmation: constant conversation, yes — knowledge of the exact pages, no.

What this says about Yamamoto

Strip away the viral framing and the notebook is really a preparation story. Yamamoto is not writing for the cameras, and there is no evidence of gimmick or gamesmanship in either report. He is logging, in the fastest way that works for him, what he just saw — location, reaction, swing decisions — while it is still fresh, then using those notes to plan the next inning with Prior and his interpreter.

That also explains why the habit has endured for two years. A tablet can show him what a pitch did. A handwritten page, in his own shorthand, can remind him what he thought while throwing it.

What's next?

Expect the cameras to find the notebook in every remaining Yamamoto start this postseason. Unless Yamamoto himself opens the pages one day, the best answers will stay the ones we already have: strike-zone sketches, swing notes, and a personal scouting report written by hand.

And honestly, that is enough. In a sport drowning in data, the most talked-about analytics tool of the NLCS might be a pen and a black notebook nobody else gets to read.

FAQ

What is in Yoshinobu Yamamoto's notebook?
No one outside Yamamoto's circle knows for certain. Reporting cited by the New York Post and USA Today suggests strike-zone drawings, circled pitches with numbers, and his own scouting notes.

Does Will Smith know what's in the notebook?
No. Smith said on October 12 that he and Yamamoto talk constantly, so it is probably the same material — but he does not know the exact contents.

Why does Yamamoto write by hand instead of using an iPad?
Former pitcher Robby Rowland believes writing pitches down by hand helps Yamamoto remember them better than using a tablet, according to both outlets.

Does Yamamoto write trash talk in it?
No. When a reporter jokingly asked if he writes that he struck a hitter out in boastful terms, Smith laughed and said he does not.