The Mental Game of Trading by Jared Tendler: Summary and Key Ideas

Where this guide comes from

• Pages from the printed book, which Tendler publishes in a free companion PDF for audiobook listeners. It includes the full table of contents, the back cover and around thirty pages of the book. Page numbers on this page refer to the printed book. It is an excerpt: where this guide relies only on a chapter heading, it says so, because a heading shows a topic is covered, not what the book says about it.
• Tendler's official book page, for how he describes the book.
• Tendler outside the book: two articles on his site, from 2022 and 2024. They show his wider teaching and are presented that way, not as text from the book.
• TradingLoot's own guidance, including the journal routine below. Those parts say so.

Why recurring mistakes may not be technical problems

The book's back cover sets out the situation it is written for. Most traders, it says, overlook or misunderstand their mental and emotional obstacles. Others believe they know how to manage them, then lose control at the worst possible time. Either way, money is left on the table.

The usual response to a repeated mistake is to improve the strategy: a new rule, a tighter filter, more study. Tendler argues this can't work on its own when the cause is emotional. If you fix only the technical side of your worst mistakes, he writes, the flaws behind them keep producing the same excess emotion, and you end up making different mistakes that are still obvious ones (p. 12). Experience doesn't make anyone immune either: "Every trader has performance flaws, no matter how experienced or skilled" (p. 12).

A TradingLoot illustration of the idea: a trader who keeps closing winners too early adds a rule to trail the stop instead. If the real driver is fear of giving back profit, the same urge tends to reappear in a new form, such as tightening the trailing stop by hand. The rule changed; the cause didn't.

A-, B- and C-game: three levels of performance

Tendler describes every trader's performance as moving between three levels: A-game at your best, B-game at your average, and C-game at your worst. The difference between them is partly emotional (p. 12). At your A-game, the impulse to make a bad trade doesn't come up, or is so small you barely notice it. At your B-game the impulse is there, say to force a trade or close one too early, but you still have the presence of mind and emotional control to resist it. At your C-game the emotion is too strong and you can't stop yourself.

Each level comes with its own kind of mistake (pp. 12, 107):

Learning mistakes (A-game)

Technical in origin, such as knowledge you haven't gained yet or a change in the market you haven't spotted. The book treats them as an unavoidable part of learning.

Marginal mistakes (B-game)

A blend of some tactical weakness and some emotional interference.

Obvious mistakes (C-game)

Errors so clear there's nothing to learn tactically. They come from emotion that is too intense, or from energy that is too low.

The book offers this as an alternative to judging each decision as simply right or wrong (p. 107), and its A-to-C-game analysis separates the mental and emotional side of each level from the tactical side (p. 42). The practical value, as TradingLoot sees it, is triage. A learning mistake calls for study or review of the strategy. An obvious mistake calls for work on the mental game, because more study won't touch it.

The Inchworm Concept

The Inchworm Concept is Tendler's model of how improvement happens. He says he created it early in his career, while explaining the learning process to poker players (p. 37). An inchworm moves by anchoring its front end, pulling its back end forward, then stretching out again. As Tendler puts it, "An inchworm looks like a bell curve that moves" (p. 37).

The bell curve is the spread of your decisions. Rate every trading decision from the last six to twelve months and they form a curve, with your C-game at one end, your A-game at the other and your B-game in the middle (p. 38). That curve is your current range. A ten-year trader can no longer think about a trade as crudely as they did six months in, and a six-month trader can't suddenly think like a veteran.

The accessible pages stop just as the book turns to how the curve moves. Tendler's 2024 article on the concept, which is outside the book, describes it as two kinds of step: your best decisions getting better at the front, and your worst ones getting less bad at the back. His point there is that weaknesses at the back are what trip people up, so working only on your best play leaves the swings in place.

Mapping triggers and emotional intensity

Chapter 2 asks traders to map their pattern: to notice and write down what happens before, during and after each mistake (pp. 27–28). That means the trigger, and also the thoughts, emotions and behavior that followed, and how your decisions and your reading of the market changed. Most traders, the book says, can spot only a few signals at first. The moment just after a mistake is the best time to gather more, and there's a side benefit: "the act of writing things down can actually help to defuse the emotion" (p. 28).

Each of the five problem chapters then asks you to map that emotion by intensity, from the point where it is small and manageable to the point where it takes over your execution, noting how your decisions change along the way (pp. 62, 84, 131, 192, 252). The aim is to recognize the pattern early, while it's still small enough to correct. The book's own maps and prompts are available from the author and aren't reproduced here.

The book also treats emotion as something that can build up. The fear chapter asks how initial worry grows into fear (p. 84), and the tilt chapter notes that a trader carrying a lot of accumulated tilt may explode almost instantly, which calls for work outside the trading day (p. 132). From the accessible pages, TradingLoot can't say how far the book develops accumulation as a framework of its own.

Greed, fear, tilt, confidence and discipline

Chapters 4 to 8 each take one problem area: its nature, its common signs, how to map it, and the specific forms it takes.

Greed

The chapter covers the nature and signs of greed and what the book calls its real cause. The accessible pages show greed being mapped by intensity, and in one case study it turns out to be fed by a weakness in confidence (p. 67). That fits the book's broader method: the visible emotion isn't always the root.

Fear

The fear chapter covers fear of missing out, fear of losing, fear of mistakes and fear of failure. Tendler describes the fear of losing as protection from the pain of losing, which shows up as quick profit-taking, smaller size or avoiding riskier trades (p. 93). He also warns about overcorrecting: trying to blast through fear by throwing caution aside can tip a trader into defiance, which removes the feeling but brings different mistakes (p. 92). For fear of mistakes, he points back to the three kinds of mistake as a less all-or-nothing way to judge yourself (p. 107).

Tilt

The book covers anger under the heading of tilt. The chapter covers hating to lose, mistake tilt, injustice tilt, revenge trading and entitlement tilt. The accessible pages explain injustice tilt through two errors in how traders keep score: blaming their own mistakes on bad luck, and crediting good luck to skill (pp. 158–159). Repeated over time, those errors make variance seem stacked against you. Tendler adds that traders tend to remember bad luck more than good, which deepens the effect.

Confidence

This chapter covers both overconfidence and lack of confidence, what stable confidence looks like, and a set of cognitive illusions and biases, along with perfectionism, desperation, and hope and wishing. Tendler argues that biases can be changed, not just guarded against, by correcting the faulty reasoning behind them (p. 193). He also describes black-and-white thinking as one reason traders swing between seeing themselves as a genius and as a fraud (p. 212). In a 2022 article outside the book, he goes further and calls confidence the base of the mental game.

Discipline

The discipline chapter covers impatience, boredom, being overly focused on results, distractibility, laziness and procrastination, plus general strategies to improve discipline, which TradingLoot knows only from the heading. The accessible pages treat discipline as something to map like the emotions, with an example of how a rough session, poor sleep and rushed preparation can combine into impulsive entries and trades outside the strategy (p. 252).

The Mental Hand History: what it's for

The Mental Hand History is a tool the book uses to get from a symptom to its cause. It is a short piece of structured writing that takes one specific problem, works back to the flawed belief or reasoning behind it, and then forward to a correction. The accessible pages show it applied to fear of losing, to revenge trading, and to greed driven by a need to prove oneself (pp. 92–93, 169–171, 212–213).

Its questions and worked examples are Tendler's own material, so TradingLoot doesn't reproduce them; the tool is in his free worksheets (email sign-up required). The principle is what matters: don't just describe what went wrong, find the specific flaw behind it and write a correction you actually believe.

Why knowing what to do isn't always enough

Many traders can describe exactly what they should have done, after the fact. The book explains why that knowledge disappears in the moment using the Yerkes-Dodson law (p. 278). Performance improves as emotion rises, but only up to a threshold. Past it, emotion starts to shut down thinking, decision-making and emotional control, and you lose access to what you know in proportion to how intense the emotion is. The most recently learned skills go first; the ones closest to mastery go last.

The threshold is personal, and Tendler suggests watching for signs that you've crossed it: biases showing up more, your decision-making changing, and some information becoming harder to reach. The other side of the curve matters too. When you're tired and short of energy, performance also suffers, and low energy appears among the causes of C-game mistakes (p. 12).

Chapters 9 and 10 cover correcting problems in real time, building a routine and troubleshooting stalled progress. TradingLoot has seen only their headings, so their methods aren't described here.

A journal reflection routine

This routine is TradingLoot's own, not a method from the book. It borrows the book's kinds of mistake and its emphasis on writing things down. It doesn't replace Tendler's tools or guarantee better results.

• Label every mistake by kind.Learning, marginal or obvious. Use the same three tags every time so they can be counted later.
• For obvious mistakes, note what came just before.One or two lines: the trigger, the thought, and anything that changed in how you saw the market. Write it soon after the trade, while it's fresh.
• Review weekly, not trade by trade.Look for triggers that repeat, such as a second loss in a row, a big winner or a missed move. A repeated trigger is a pattern worth working on.
• Keep strategy review separate.Learning mistakes go to your strategy notes; obvious mistakes go to your mental-game notes. Mixing them hides both.
• Track the back end over months.In the spirit of the Inchworm Concept, check whether your obvious mistakes are becoming rarer or milder, not only whether your best trades are improving.
• Work through a recurring pattern in writing.When one pattern keeps returning, use Tendler's official worksheets rather than a reconstruction of them.

Most trading journals support custom tags, which makes the counting practical. To choose one, see Trading Journal Software Compared. TradingLoot also reviews StopTilt, a behavioral discipline tool.

StopTilt shares common ownership with the TradingLoot ecosystem. This relationship doesn't change how StopTilt is described here.

Possible misreadings

These are ways the book could be misread, as TradingLoot sees it, each checked against the accessible pages.

"The goal is to get rid of emotion."

The opening chapters frame emotions as signals to use and learn from, and the Yerkes-Dodson curve shows emotion helping performance up to a point. The problem is emotion past your threshold, not emotion itself.

"Mental-game work replaces strategy work."

Learning mistakes are technical by definition, and they need technical work. In his 2022 article, outside the book, Tendler also recommends balancing the two.

"Experienced traders have grown out of this."

The book says the opposite: experience raises the floor of your decisions, but it doesn't remove performance flaws (pp. 12, 38).

"Map it once and you're done."

The book calls mapping an iterative process and says the small signs are there even when you can't see them yet (p. 63). Tendler's 2022 article goes further, arguing that the mental game is never fully solved.

"The cure for fear is to push through it."

The book warns that pushing through can swing into defiance and a new set of mistakes.

Who it's for

This is TradingLoot's guidance, based on the book's description and the accessible pages. Tendler's book page says the system applies to independent and institutional traders, across equities, forex and cryptocurrencies.

Likely to suit

• Traders with a defined strategy whose same costly mistakes keep coming back.
• Traders who can already name their pattern, such as revenge trading, FOMO or moving stops.
• Readers willing to write things down and review them; the book is built around that work.

May not need it yet

• Readers looking for setups, indicators or a trading system.
• Traders who don't yet have a defined approach. Most of their mistakes may still be learning mistakes, which the book itself treats as technical.
• Anyone wanting a quick read: the contents run past 300 pages.

How it complements Trading in the Zone

Mark Douglas's Trading in the Zone centres on a way of thinking: an edge as a probability, wins and losses arriving in random order, and judging yourself over a series of trades. The Mental Game of Trading centres on a process: identifying the specific emotional pattern that keeps breaking your execution and tracing it to its cause.

In TradingLoot's view, the two answer different questions. Douglas helps with how to think about any single trade. Tendler helps when you already accept that thinking but a particular reaction keeps overriding it. Both treat inconsistent execution, not a lack of setups, as the core problem. The comparison is based on the sources each page lists. For more options, see trading psychology books.

Key takeaways

• Mistakes that survive technical improvement are likely to have an emotional cause.
• Learning, marginal and obvious mistakes need different responses.
• Improvement means lifting your worst decisions, not only your best ones.
• Map what happens before, during and after a mistake, and catch the pattern while it's small.
• The emotion you see, such as greed, may be driven by something else, such as confidence.
• Past your emotional threshold, what you know becomes harder to use, newest skills first.

Related book summaries

• 

  Trading in the Zone summary

  Mark Douglas

  The case for thinking in probabilities: judging an edge over a series of trades, not on the last result.

• 

  Technical Analysis of the Financial Markets summary

  John J. Murphy

  A broad technical foundation, for the learning mistakes Tendler treats as technical rather than emotional.

Related TradingLoot resources

• Trading Psychology Books: more books grouped by the problem they address.
• Trading in the Zone by Mark Douglas: our summary.
• Trading journal reviews: Edgewonk, TradeZella, TraderSync and Tradervue.
• All book guides.

Book details

TradingLoot doesn't claim a first-hand reading of this book. The details below say what its description is based on.