The strike zone idea,
applied to investing.

In 1971, Ted Williams — arguably the greatest hitter in baseball history — published The Science of Hitting. The book described how he had mentally divided the strike zone into 77 cells, each roughly the size of a baseball. He had studied his own batting statistics carefully enough to know exactly which cells produced his best results.

Swinging only at pitches in his "best" cell — the high-inside fastball — Williams hit .400. Reaching for pitches in his "worst" cell — the low-outside corner — dropped his average to .230. The physical mechanics of the swing were similar. The difference was what he chose to swing at. The willingness to only swing at the right pitches is what put him in the Hall of Fame.

Buffett read Williams' book and saw something that had nothing to do with baseball. He saw a framework for decision-making under pressure — and the same lesson applies. The investors who become legendary aren't the ones who swing at the most pitches. They're the ones disciplined enough to swing only at the ones in their best cell.

A batter who takes three strikes is out. An investor who watches a thousand stocks pass without finding one that meets their standards has lost nothing. Patience costs nothing. Activity costs plenty.

This is the structural feature that makes the strike-zone idea work in investing even better than it works in baseball. You don't lose by not swinging. You lose by swinging at the wrong things.

And almost every investor swings too much. The market generates an enormous volume of stimulus — earnings, news, prices, opinions — and every piece of it is an invitation to act. The investors who outperform tend to be the ones who decline most of those invitations and act decisively on the few that match a framework they wrote down before the pressure started.

A strike zone, for an investor, is a written set of criteria that defines what a genuinely great investment looks like to you. Not to the market. Not to an analyst. To you — given your knowledge, your risk tolerance, your investment horizon, and the businesses you actually understand.

It typically has three layers:

1. 1 Your circle of competence. The industries and business models you understand deeply enough to evaluate — not just follow the news on. This is usually narrower than you think.
2. 2 Your investment standards. What you'd need to see in a business before you'd consider owning it. That might be classic quality signals — competitive moat, management integrity, capital allocation discipline — or specific catalysts you're watching for: a landmark drug approval, a new market they're about to enter, a turnaround that's actually taking hold.
3. 3 Your price threshold. The discount to fair value you require before acting. A great business at the wrong price is a poor investment.

Stay inside your circle of competence

Most investors overestimate the size of their circle. They follow an industry, read the headlines, and feel confident. Confidence and competence are not the same thing. Strike Zone is built so the standards you write down apply to the companies you understand — and quietly let the rest go by.

The strike-zone discipline is not novel — it's just consistently undervalued by a market that rewards activity. Almost every investor with a multi-decade track record has come back to it in some form.

What's common across all of them: the framework precedes the decision. You don't decide what kind of investor you are while looking at the chart. You decide it earlier, in writing, when the price isn't moving and your judgement is calm.

The hardest part of maintaining a strike zone isn't defining it. It's applying it consistently across thousands of stocks, every day, without losing either depth or rigour.

Most investors with well-defined criteria end up doing manual research on companies they could have ruled out immediately with a quick filter. That's the gap Strike Zone closes.

The product lets you encode your criteria — both the quantitative thresholds and the qualitative questions — and evaluates them systematically across the full universe of globally listed equities. The LLM does the reading you'd do yourself, asks the questions you'd ask, and surfaces only the companies that survive your full framework.

The survivors are what we call Fat Pitches: the rare investments that meet every one of your standards, at a price that makes the risk worthwhile. The ones Ted Williams would have stepped up for.

A defined strike zone has a quiet side effect. Once the daily work of screening, monitoring valuations and re-checking criteria is handled, the most valuable thing it gives back isn't a longer watchlist. It's your time.

That time is the raw material of an investor's career. Spent on the wrong things — reacting to headlines, chasing tickers across sectors you don't really understand, re-doing work you've already done — it disappears. Spent on the right thing, it compounds.

The right thing to spend it on, in our view, is depth. Pick one industry you've always meant to learn — semiconductors, biotech, marine logistics, payments, defence, whatever sits just outside your circle today — and study it until it earns a place inside. Read a few annual reports end to end. Talk to people who work in it. Build a mental model of how its businesses actually make money, and what can go wrong.

Then write a strike zone for it. Add it to your screener alongside the others. You now have one more place on the field where you can recognise a fat pitch when it crosses the plate — and the screener will quietly watch that ground for you, every day, while you go and learn the next one.

The investors who quietly compound over decades aren't the ones who swung at more pitches. They're the ones whose strike zone kept getting sharper, in more places. That's the version of this product worth building — not a faster way to react, but a steadier way to grow.