How competition odds work: current vs if-sold-out

Odds in a prize competition are just a fraction. If a competition has a fixed number of tickets and the winner is drawn at random, your chance with a single ticket is:

1 ÷ total tickets

So a competition capped at 5,000 tickets gives each ticket a 1-in-5,000 chance, written as odds of 1:5,000, or 0.02%. The fewer tickets in total, the better each one does. This is the number you actually care about. What matters is not how big the prize is but how many ways it has to be split.

The catch is the phrase "total tickets". Most sites display your odds based on the tickets sold at the moment you look, which is a very different, and much more flattering, number than the total that will exist when the competition closes.

Buying several entries scales your chance more or less linearly, as long as the draw is one ticket pulled from all tickets. With t tickets out of a total of N, your chance is:

t ÷ N

Ten tickets in a 5,000-ticket competition give you 10-in-5,000, which simplifies to 1-in-500. Twenty tickets gives 1-in-250, and so on. It's proportional: double your tickets, double your chance. What buying more entries does not do is change the total. Every extra ticket you buy also nudges N upward, and other entrants keep buying too. Which brings us to the mistake almost everyone makes.

When a competition is fresh and only a few hundred tickets have sold, the "odds" displayed look fantastic, sometimes 1-in-200 or better. It is tempting to read that as your real chance. It isn't. Those are the odds so far, based on tickets sold to date, and they get worse every time anyone else enters before the draw.

Most competitions sell many more tickets between the moment you look and the moment they close. A figure that reads 1-in-300 on launch day can drift to 1-in-3,000 or worse by the closing time. Treating today's number as final is the single most common error people make when judging a competition. The current figure is a snapshot, not a forecast. Always read it as provisional.

If a competition has a ticket cap (a maximum number of tickets it can ever sell) then there's a hard floor on how good your odds can be. That floor is the if-sold-out figure: your chance if every available ticket sells.

if-sold-out odds = 1 ÷ ticket cap

It is the realistic worst case, and for any competition that's likely to sell out it's also the honest planning number. A competition capped at 5,000 tickets has if-sold-out odds of 1-in-5,000 no matter how empty it looks today. If you'd be happy entering at 1-in-5,000, the current 1-in-300 is a bonus; if 1-in-5,000 puts you off, the flattering launch-day figure shouldn't change your mind. Always compare competitions on their if-sold-out odds, not their current odds. It's the only figure that's stable.

Some competitions have no published ticket cap at all: entries are unlimited, or the limit isn't disclosed. Here the if-sold-out trick doesn't help, because there's no ceiling to anchor to. Your final odds depend entirely on how many people enter before it closes, which you can't know in advance.

That uncertainty is itself worth weighing. With no cap, a popular prize can attract far more entries than you'd guess, and your real odds can be much worse than the current figure suggests. A published total-ticket count is one of the trust indicators CompWatch looks at when grading a site, precisely because it lets you judge your chances honestly. Where no cap exists, treat the current odds as an optimistic upper bound and nothing more.

Suppose a competition is giving away a prize with a cash alternative of £10,000. Tickets cost £2 each, and the competition is capped at 10,000 tickets. On the day you look, 1,000 tickets have sold.

For every live competition we track, CompWatch shows the current odds and the if-sold-out odds side by side, so you can see the snapshot and the realistic worst case at a glance. We never present a provisional figure as if it were final.

We also rank competitions by value using the if-sold-out expected value, not the flattering current number, because ranking on current odds would simply reward whichever competition launched most recently. You can browse the results on best odds, see how the value sums shake out on best value, and read the fuller method in our guide to finding the best-value competitions. A published ticket cap is also one of the indicators behind each operator's trust grade, since you can't judge odds honestly without it.

The if-sold-out figure is the realistic ceiling, but in practice plenty of competitions close before they sell out. The interesting question is: where will the odds actually land at the draw, somewhere between today's snapshot and the full cap?

Power Mode, our paid tier, estimates that. It gives you a spreadsheet view of every competition with predicted final odds based on how each one is selling, plus email digest alerts and entry-and-winnings tracking so you can see how your real-world results compare to the odds you went in on. For most people the free current-and-if-sold-out view is enough to enter sensibly; Power Mode is for those who want the projected landing point rather than just the two endpoints.