Appreciating the Role of Luck

Imagine two children playing a board game with one dice. Rohan needs a six to win, and he needs it so badly that he closes his eyes, whispers a wish, and rolls without even thinking. Up comes a six. He jumps around the room shouting that he is the best dice-roller in the world. Haridya, playing carefully, works out that she has the best chance if she rolls for a four, aims her throw gently the way she always does - and gets a two. She loses.

Now, here is the question that this whole chapter turns on. Who played better?

Most of us, watching only the ending, would say Rohan. He won, didn't he? But if you think for one more second, you know that a dice doesn't care who wishes hardest. Rohan didn't play well; he got lucky. Haridya didn't play badly; she got unlucky. The result - win or lose - told you almost nothing about who made the smarter move. The dice landed the way it landed, and it happened to reward the careless child and punish the careful one that single time.

That gap - between how good a choice was and how well it happened to turn out - is one of the most important and most ignored ideas in all of investing. When you buy or sell a share, you are Rohan and Haridya at once: you make a decision, and then a world you cannot control rolls its dice. A good decision can end badly. A bad decision can end wonderfully. And if you judge yourself, or anyone else, only by the ending, you will learn exactly the wrong lessons - you'll praise the lucky fool and scold the careful thinker. In any game where luck plays a big part, the result of a single decision is a noisy, unreliable signal - so grade the choice by how sensibly it was made, not by the one outcome the dice happened to hand you.

You might ask: if the result is all I can see, why not just use it? The answer is that in investing the result is a scoreboard that lies - it mixes together two completely different things and never tells you which is which.

Every outcome you ever see is really two ingredients stirred into one number. One ingredient is your skill - the quality of your thinking, your patience, your homework. The other is luck - everything that happened in the wide world that you could never have known or steered: an election result, a war on the other side of the planet, a monsoon, a sudden change in oil prices, a rumour that catches fire on a Tuesday. When your money goes up, you cannot easily tell how much was your good judgement and how much was a friendly roll of the world's dice. When it goes down, you cannot tell how much was your mistake and how much was plain bad weather.

This matters enormously, because the whole point of learning is to repeat what works and drop what doesn't. But if you cannot separate skill from luck, you'll repeat the wrong things. You'll say "that reckless bet paid off, so reckless betting must be smart," and next time the dice won't be kind. You'll say "that careful plan lost money, so careful planning is for losers," and you'll throw away the very habit that would have protected you over a lifetime. The lying scoreboard doesn't just confuse you once. It quietly trains you to become a worse investor, one wrong lesson at a time.

There is a simple test grown-ups use to sense how much luck rules a game: can you lose on purpose? In chess, you can throw a game any time you like by making deliberately silly moves - which proves skill is in charge. But try to lose a single coin-flip on purpose. You can't; the coin decides, not you. The more a game resembles the coin-flip, the more luck runs the short-term result - and short-term buying and selling of shares sits far, far toward the coin-flip end. The easier it is to lose a game on purpose, the more skill controls it; short-run investing is nearly impossible to lose on purpose, which means a handful of good or bad results tells you almost nothing about whether the method behind them was any good.

It's worth slowing down on why short-term investing sits so close to the coin-flip end of the scale, because once you feel it, you'll stop being surprised that results and skill drift so far apart.

Think about what actually moves a share price from one week to the next. It isn't only how well the company runs its factories. It's what millions of other people, all over the world, happen to feel and do about that company on any given day - and their moods are stirred by things no one can predict: an interest-rate announcement, a scary headline, a festival, a rumour, a big investor abroad needing cash and selling. You can pick a genuinely excellent company at a genuinely fair price - a truly good decision - and still watch its price sag for a year because the whole market caught a cold for reasons that have nothing to do with your company. The link between "I chose well" and "the price went up soon after" is loose, jumpy, and full of static.

Compare that to a game like chess, where if you play better moves you almost always win, and where - remember the test - you could choose to lose any time by playing badly on purpose. You cannot choose to make your share fall next month; a thousand strangers decide that, not you. That single fact tells you how much luck is in charge of the short run. It doesn't mean the game is hopeless. It means the scoreboard over a few months is close to a coin - and anyone who reads deep meaning into a few months of it, up or down, is reading tea leaves. The sensible response is not despair; it's patience, spreading your money out, and refusing to let a short, noisy stretch rewrite your whole plan.

To think clearly about this, we have to stop treating "good decision" and "good result" as the same words. They aren't. Once you pull them apart, every choice you or anyone makes drops into one of four boxes.

You can make a good decision and get a good result - you thought carefully and the world was kind. Lovely, but be careful: this is the box where people get overconfident, because they can't tell how much was them and how much was luck. You can make a good decision and get a bad result - you thought carefully and the world was cruel anyway. This is the box that feels like failure but usually isn't; it's Haridya rolling a two. You can make a bad decision and get a good result - you were careless and got away with it. This is the most dangerous box of all, because it teaches you that carelessness works; it's Rohan and his lucky six. And you can make a bad decision and get a bad result - careless and punished, the only box where the lesson is honest and simple.

Look hard at the two boxes that don't match - the top-right and the bottom-left. Those are where nearly all the confusion in investing lives. The careful person who lost (top-right) gets mocked and starts doubting a perfectly good habit. The careless person who won (bottom-left) gets praised and doubles down on a habit that will eventually wreck them. Your job, every time you look at a result - your own or anyone else's - is to guess which box the thinking really belonged in, and to refuse to let the result alone decide it for you.

Let's put real rupees down and watch the four boxes come alive. illustrative

Two cousins each receive ₹1,00,000 on the same day and decide to invest it. Rohan does no reading at all. He hears one loud tip about a small company that makes phone accessories, likes that its price has doubled recently, and puts the whole ₹1,00,000 into that single share. He owns nothing else. Haridya spreads her ₹1,00,000 across a plain, boring basket that tracks the whole market - hundreds of companies at once - because she knows she can't predict which single one will win, and she doesn't want one mistake to sink her.

Now the world rolls its dice. Over the next eight months, a surprise government order suddenly makes that one phone-accessory company very popular, and its price doubles again. Rohan's ₹1,00,000 becomes ₹2,00,000. Haridya's broad basket drifts up a calm 9% to ₹1,09,000. Rohan is thrilled and a little smug. At the family dinner he explains that reading reports is a waste of time, that you just have to "back a winner," and that Haridya's careful spreading-out is for timid people.

But walk through what actually happened. Rohan put everything into one unknown company chosen on a rumour - a bad decision, the kind that, repeated, blows up sooner or later. It landed in the bottom-left box: bad decision, good result. Haridya spread her money wisely so no single company could hurt her badly - a good decision - and it happened to give a modest return this time, but it was never going to ruin her. The scoreboard crowned Rohan. The thinking crowns Haridya. And here is the quiet danger: Rohan didn't just get lucky once; he learned from his luck that recklessness works, and he'll bet even bigger next time - right up until the dice roll the other way and one bad bet takes the lot. His good result taught him a bad lesson, which is the most expensive kind of luck there is.

The trap of judging by results has a favourite disguise, and almost everyone falls for it at least once: chasing last year's winner. Let's watch it. illustrative

Arjun wants to start a monthly SIP of ₹5,000 into a mutual fund, and he does the thing that feels most sensible in the world - he looks up which fund did best last year and picks that one. Last year, a fund we'll call the "Rising Star" fund shot up 48% while most others managed a plain 12%. To Arjun this looks obvious: the Rising Star manager is clearly the most skilled, so ride that skill.

But think about what a single great year really is. In a game this heavy with luck, one year is barely more than a few rolls of the dice. The Rising Star fund happened to bet heavily on one corner of the market - say, small fast-growing companies - and that corner happened to have a golden year. That's not proven skill; it's a lucky roll dressed up as genius. The very thing that made it soar (a big, concentrated tilt toward one type of company) is exactly the thing that can make it plunge when that corner falls out of favour.

And that is roughly what happens. Over the next two years, small companies have a rough patch. The Rising Star fund falls 20% one year and limps the next, while the plain, boring, spread-out fund Arjun ignored keeps compounding steadily. Arjun's ₹5,000-a-month, which he poured into last year's hero, ends up well behind where the dull fund would have left him. He didn't buy skill. He bought a good result and hoped it was skill - and the two are not the same. A single dazzling year is a result, not a proof of skill; picking tomorrow's investment purely because of yesterday's return is grading the choice by the dice, and the dice do not repeat on command. The honest way to have chosen a fund was to look at its process - is it sensible, spread-out, low-cost, run the same steady way for a long time - not to sprint toward whichever number was biggest last December.

We've seen a bad decision rescued by luck and a good result mistaken for skill. Now watch the most heartbreaking slip of all - a genuinely good decision that its owner throws away because one unlucky year made it look wrong. illustrative

Aarvi does everything right. At 26 she sets up a steady SIP of ₹8,000 every month into a plain, spread-out index fund, promising herself she'll keep it running for fifteen years no matter what. This is a fine decision - patient, low-cost, spread across hundreds of companies, exactly the kind of process that tends to reward people who simply don't interfere with it. For two years it ticks along nicely and she feels clever.

Then the world rolls a bad year. A global scare sends markets down hard, and her fund falls 28%. The ₹2,40,000 she has put in over two-and-a-half years is now showing as roughly ₹1,90,000 on her screen. Every month her SIP buys in and the number still looks red. Friends who "got out early" sound wise. The pain is loud, and outcome bias goes to work on her: "The plan lost money. The plan was wrong. Stop the plan." So she cancels the SIP and pulls her money into a savings account to "wait for things to calm down."

Look carefully at what she actually did. Her decision to run a steady, spread-out SIP was a good decision - top-right box, good choice, unlucky short-term result. The falling market wasn't proof she chose badly; it was a rough roll of the dice that a fifteen-year plan was built to ride through. Worse, cancelling during the fall did two cruel things: it turned a temporary paper dip into a real, locked-in loss, and it stopped her buying at exactly the cheap prices that make long plans work. When the market recovers over the next two years - as broad markets have historically tended to, eventually - she's on the sidelines for the rebound, and the friends who "got out" mostly get back in far too late. Aarvi didn't have a bad plan. She had a good plan and a bad year, and she couldn't tell the two apart - so she scrapped the plan and kept the mistake. Abandoning a sound, sensible process because a single unlucky stretch made it look bad is the outcome trap at its most expensive - the choice was right on the day you made it, and one cruel result doesn't unmake it.

Now for the deepest and strangest part of the idea, and it explains why the world is full of confident-sounding "geniuses" who are really just lucky survivors. illustrative

Imagine a giant coin-flipping contest. One thousand people each flip a coin. Everyone who flips heads stays in; everyone who flips tails is out and goes home. Flip once: about 500 remain. Flip again: about 250. Again: about 125, then 60, then 30, then 15, then 7, then 3, and after ten rounds, one person has flipped heads ten times in a row. A crowd gathers around this person. Newspapers call them the greatest coin-flipper alive. They write a book: Ten Heads in a Row - My Winning Mindset. And people believe it, because look at the record! Ten out of ten!

But you and I know the truth: that person has no skill whatsoever. A coin cannot be flipped skillfully. With a thousand people flipping, it was almost certain that someone would get ten heads in a row purely by chance. The "genius" is simply the one the dice happened not to eliminate. And here is the part almost everyone misses - the reason the illusion is so convincing. We only ever see the winner, standing on the stage. We never see the 999 people who flipped exactly the same way, made exactly the same "bets," and got knocked out. They went home quietly and no one wrote about them. The evidence that it was all luck - the huge pile of identical losers - is invisible.

You can see the same machine running whenever a bull market is roaring. When the Sensex and Nifty climb for a couple of years straight, almost everyone who bought boldly looks like a wizard, and social media fills with confident young "experts" posting their winning screenshots. It feels, in that moment, as though picking winners is easy and everyone doing it is skilled. But a rising tide lifts the reckless boat and the careful boat alike - and the thousands whose bold bets already sank in the same period simply don't post. The loud chorus of winners during a boom isn't proof that skill is everywhere; it's proof that the tide is high and the losers are quiet.

This is exactly how investing manufactures false heroes. Start with tens of thousands of people all making bold, concentrated bets. By pure chance, a few will string together several great years in a row. Those few become famous, sell courses, gather followers who copy every move - while the thousands who bet just as boldly and got knocked out vanish without a trace. When you look only at the survivor and think "clearly a genius, look at the record," you are being fooled by the missing graveyard. Every field with many players quietly produces a lucky champion, and you only ever see the champion - the crowd of identical people who did the same thing and failed is invisible, so a shiny track record can be pure survival, not skill. Before you copy anyone's winning streak, always ask the uncomfortable question: how many people tried the exact same thing and are not here to talk about it?

The slip is called outcome bias, and it's one of the stickiest mistakes there is: judging a decision as good or bad purely by how it turned out, forgetting that a foggy world stood between the choice and the result.

It works on you in two directions, both harmful. When a careful, sensible choice happens to lose money, outcome bias whispers that you were wrong to be careful - and you're tempted to abandon a perfectly sound habit after one unlucky year. When a reckless, silly choice happens to make money, outcome bias whispers that recklessness is clever - and you're tempted to repeat it with more money, until the dice turn. Notice that both whispers push you the same terrible way: away from careful process and toward chasing whatever just worked. That is the machine that turns ordinary people into performance-chasers, buying last year's winner right before it cools and selling last year's laggard right before it recovers.

Now the honest part, because "it was just bad luck" is a comforting sentence that can quietly rot into an excuse.

The first limit is the most important: one outcome is noise, but many outcomes are a signal. If a careful plan loses one year, that's very likely bad luck, and you should hold steady. But if the same approach loses money across many different years and many different market weathers, then at some point "I was just unlucky" stops being true and "my process is actually flawed" becomes the honest answer. The whole point of separating luck from skill is to judge fairly over a long record - not to hide from every bad result forever by blaming the dice. A good investor uses "it might be luck" to stay calm through one rough year, and uses "a long pattern is evidence" to stay humble and keep learning. Aman, who loses steadily for six years across booms and busts alike and keeps saying "just unlucky," isn't appreciating the role of luck; he's using it as a blindfold.

The second limit: luck cutting both ways doesn't mean everything is luck and effort is pointless. In the short run, a coin-flip rules; but over a long career and repeated decisions, genuine skill - spreading your money sensibly, keeping costs low, staying patient, avoiding ruin - really does separate from luck and show up in the results. The lesson isn't "nothing you do matters, so why try." It's the opposite: because the single result is so noisy, the one thing worth pouring your effort into is a sound, repeatable process - the part you actually control - and then giving it enough years for luck to average out. Over a small sample luck dominates and results are almost meaningless, but over a long enough record real skill does emerge - so distrust short streaks, respect long ones, and put your effort into the process rather than the roll.

The third, quieter caution: the coin-flip lesson can tip you into sneering at everyone who succeeds as "just lucky." Some winners really are skilled. Survivorship bias tells you a shiny streak could be pure survival - not that it always is. The grown-up move isn't to dismiss every champion, nor to worship them; it's to stop staring at the streak and go look at the process underneath it. Sensible, spread-out, honest, repeatable? Then some skill is likely there. All bold concentrated bets that happened to land? Then you may be looking at the lucky coin. The idea is a tool for looking closer, not a reason to stop looking.