#预测世界杯法国VS伊拉克 The real probability is completely different from the probability we imagine. If something has a 90% chance of being true, then it has a 10% chance of being false. But think about it: if it’s 95% true, then it’s 5% false.

When a goal is scored, there’s a chance of it going in—something like 70%–80%—and there’s a chance of it not going in—something like 10%–20%. In 90 minutes, suppose a total of five goals are scored: three by France, and at least one by Iraq.

In the first 20 minutes, there are several possibilities:
1) Neither side scores.
2) France scores one goal.
3) Iraq scores one goal.
4) France scores one goal, and then you multiply by 9 2/9, which equals 1.1.

But what about the probability of not scoring? It’s 1.1 multiplied by 10%. Since 10% corresponds to a draw, then add the probability that Iraq scores: 5% multiplied by 1/3. The 5% is because Iraq might score more than France. Add about 11% plus 1%. So, in the first 20 minutes, the probability that the match has not been decided (no winner is determined) is about 12% or slightly more.

And if in the first 20 minutes no winner is determined, then the probability that France scores a goal in the first 20 minutes is 88%. If in fact they didn’t score, then because the total match length is 90 minutes, it equals 2/9—so that becomes 5% divided by 7/9, which is a bit over 6%.

Now, if we assume a 20% return rate, the actual return should be higher. So we can draw a conclusion: in the first ten minutes, as long as no goal is scored, the probability of the original losing side increases. In other words, when you “bet on” something, you’re betting on probability.

Let’s assume that in the World Cup, teams with very large differences in strength have a 50% probability of scoring in the first ten minutes—but your return rate can be over 19%. The reason is that while we don’t know the probability of goals in the first 20 minutes, the probability of scoring in the first ten minutes is known. So for any team with a winning probability below about 4% (around 3%), you buy; at 5%, you sell.

If a goal is scored in the first ten minutes, the win probability drops to 2%, so you sell. If no goal is scored in the first ten minutes, the win probability rises to 5%, so you buy. By doing this across the whole “100比” range and finding the 10% that is certain, you can ensure your investment ratio is positive.

For example, if the current price/odds are 2%, and you estimate the probability that it ends 0-0, then you buy and hold. If you believe the probability is 5%, then you sell at 4%, because most people can only think at the first layer. If you think at the second layer, then you’ll win—there’s no need to think about the third layer, because most win-rate calculations are based on the first layer.

If you have some of your own ideas and invest long-term accordingly, you will succeed. Don’t try to get rich overnight—stable 1% over the long term is the real investment secret. Thanks, everyone.