Lorraine Williamson
El Gordo odds explained properly can feel like someone turning the lights on in a room full of wishful thinking. And yet, on Monday 22 December, Spain will still pause for the Christmas Lottery draw at Madrid’s Teatro Real — because this is about more than maths.
Every year, the country performs the same small rituals. Offices share a number. Families split décimos. Bars run syndicates. It is hope, priced at €20 a ticket, and sung out loud by the children of San Ildefonso as the morning rolls on.
The draw that stops Spain — even when the odds don’t change
This year’s top prize, El Gordo, pays €400,000 per décimo. The second prize pays €125,000, and the third €50,000. The chance of landing El Gordo with a single décimo is still 1 in 100,000.
There is also more play money overall. In 2025, the draw has 198 series per number and a total prize pool of €2.772 billion (70% of the total issue). That creates more winners, but it does not make any one ticket luckier.
A mathematician’s “insurance policy” — and what it’s really for
Enter Francisco Pedroche, a professor of applied mathematics and a specialist in probability. His idea has travelled fast in Spanish media because it sounds like a hack — until you do the sums.
Pedroche’s suggestion is simple: buy 100 décimos covering every two-digit ending, from 00 to 99. It is not a plan to get rich. It is a plan to avoid the emotional sting of getting absolutely nothing.
What 100 different endings guarantees — and why it still loses money
Buying 100 décimos costs €2,000. The “guarantee” comes from the smaller prizes linked to endings, not from any improved shot at the jackpot.
Here is the key bit most people miss:
-
Two last digits:
If your last two digits match those of El Gordo, you win €100 per décimo (and the same €100 applies for the last two digits of the second and third prizes). -
Last digit (reintegro):
If your last digit matches El Gordo’s last digit, you get €20 back per décimo.
With all endings covered, you are guaranteed:
-
€300
from matching the last two digits of the 1st, 2nd and 3rd prizes (one décimo each). -
€200
from reintegros, because 10 of your 100 endings will share El Gordo’s final digit (10 × €20).
That is €500 back in the “worst case” Pedroche describes — and a €1,500 loss if nothing else lands.
So yes: it reduces the chance of a total wipe-out. It does not turn the lottery into an investment.
The point he keeps repeating: the jackpot odds don’t budge
Pedroche’s real target is a stubborn misunderstanding. People talk as if buying more tickets “changes” the probability of a specific number. It doesn’t.
Each décimo still has the same 1-in-100,000 chance of being El Gordo. Buying more tickets only buys you more separate chances — and a bigger bill.
It also does nothing for superstition. “Due numbers”, “lucky dates”, numbers that “haven’t come out for ages” — they all reset to equal probability when the balls go into the drum.
Why Spain keeps playing anyway
If the maths is so blunt, why does El Gordo still feel irresistible?
Because it is not just gambling. It is social glue. A shared number is a shared story, already half-written: imagine if… The prize is not only money. It is a few weeks of collective daydreaming, and one morning when the whole country seems to listen at once. EsMadrid+1
And yes, psychology matters. Humans are famously bad at feeling the difference between “unlikely” and “almost impossible”. That gap is where lottery culture lives.
How to keep it fun — without the regret
A decent rule is to treat your spend as the price of joining the ritual. Set a limit you won’t resent in January. Split with friends if you like, but keep proof of what you bought and what share you hold.
Most of all, remember the line that matters: El Gordo odds explained does not have to kill the joy. It can protect it — by keeping expectations realistic.
Sources: