Probability of winning a giveaway, I don't get it

Well it matters as much as the data tells you if you were as unlucky as you imagine, or not.
I won 5 games during the first 4 days this month. But since then I have been so unlucky that I currently reached -4 for May.
So you can choose GAs that increase your chances and your stats will show that. But better chances don't guarantee success.

The probability of winning a given giveaway is equal for everyone. The stats page shows you your personal accumulated probability considering the giveaways you are in and the # of entries at that moment (the real probability is lower since people will always continue to enter it until it ends).

I think its the calculation based on the odds of the GA you entered, its not saying you should have won but you could have won on the odds of "X"

if you want to increase your odds, enter GA with multiple copies of the same game or group/private GAs.

im not sure how much it is useful maybe if you wish to see if you changed your pattern of choosing GA over time :-)

edit - grammar fix :-S

You win some, you lose some (more). Simples.

Too truly improve chances of winning you should join groups and if you end up on peoples whitelists since these ga's tend to have fewer entrants your chances go up. oh and be active on the forums peole tend to post trains and stuff.

I understand, kinda

Be patient. I win an average of 1 game per 300 entries BUT with much higher level than you (which means more giveaways with less entries), lurking on forums (which means more giveaways with less entries), having more whitelists (which means more giveaways with less entries) and being in more private groups (which means more giveaways with less entries) ;) And my first win was after a year since joining the site, not after one day! IOvOI

Usually, it's easier to win a giveaway that has a small number of entries. Still, luck always matters, because there could be someone that enters giveaways that have 5 entries and never wins anything and there could be also someone that enters giveaways that have 1000 entries and keeps winning all the time. :P

Okay good to know

Level 0 giveaways usually have significantly more entries, raising level will give you access to more giveaways with less entries.
Monitoring forums (General section) for invite-only giveaways may increase your chances significantly, but requires time.
Puzzles section has even more invite-only giveaways, but requires a lot of time.
Edit: And, obviously, entering more cheap (in points) giveaways as opposed to fewer expensive ones generally gives better chances.

probability of winning a giveaway=(copies/entries)*100%.

Examples:
If you are only one entrant in a one-copy giveaway it's (1/1)*100=100% - this means you would always win. It's obvious, right?
In case if you are one of the hundred entries of a giveaway with 5 copies of a game it's (5/100)*100=5% chance to win. it means, that from 100 of giveaways with those chances you'll probably win in about 5 of thme. It could be more or less of 5, based on your luck, because it's just a probability.

If you flip a coin, there's 2 outcomes, with equal chances: so there's 100% / 2 = 50% chance of the outcome of your choice happens.
A dice has 6 - so chance of getting a number of your choice is 100% / 6 = around 16.6%. If you want to roll the odd numbers (1,3,5) then your chance is 100% / 6 (chance of rolling a side you want) 3 (because 3 different ones are good for you ) = 16.63 = 50%
So generally, your chance to get the result you want is 100% / (number of outcomes, if same chance) * (good outcomes)

If we use this for giveaways: there's a giveaway with 1000 entries, that's like a 1000-sided dice: and only one side is good for you, because that's when you win. So, your chance to win is 100% / 1000 = 0.1%. As 100% equals of surely happens, 0.1% means one out of 1000 - so statistically it'll take you 1000 giveaways with 1k entries each to win one. (Reality can work differently, winning much sooner or later, multiple times, etc)

If there are more copies, then there's a bigger chance, obviously.
In case of a 2-copy giveaway, it doubles your chance to win, because 2 copy statistically equals with having half of the entries. ( 1000 entry for one game, or 2000 entry for 2 copy - easy to see that there's one game for 1000 entrants in each case)

So, in short: in case of 1 copy GA, your chance to win is 1/(entry number). In case of multiple copies, this is modified to (copy number) / (entry number)

The only way you can increase your sheer chance of winning by entering giveaways with low entry numbers, nothing else. But don't forget that it's better to not win for a while, and then winning a game you really want to than entering for bad, unwanted games with low entry numbers just for the sake of winning. Keeps the magic fresh :)

None mentioned yet that there are some wallpapers to add as background to incrase chances, only applies to bundle games should be said!
Check more in here, personally I use the "peasant" version :)