Winning chances [aka "Math-freaks, help me!"]

Its a legit problem and sadly I am not a math freak so i can't help you ;)

1/ people in the giveaway x 100 = your chances

U can win 10 in a row if you are lucky , u have to be really freaking lucky do, or be in groups with no people at all and u win the giveaways made there .

BUT: If you win just one giveaway, it's more unlikely that you will win a second one. And if you would win a second one, it's even more unlikely that you win a third one! Or am I wrong?

You are indeed wrong. The chances of winning in any particular giveaway are not affected by previous success, only by number of entries and number of games being given away. Look up Gambler's fallacy.

Your chance of winning is the same for each giveaway. 1:[total entries]. Winning a giveaway does not effect your chances in the next giveaway.

On Roulette wheels in the casinos, they show what the last dozen or so spins have landed on. If the last 10 spins have landed on black, it doesn't mean the next spin is more or less likely to land on black. It still has that same chance of landing on black every time (we'll say 50% for the ease of understanding). A result of "black" doesn't chance the chance on the next spin. What are the chances on it landing on black 11 times in a row? Very small. But it doesn't matter. It still has a 50% chance of landing on black on the next spin.

This is an incorrect. If you enter a giveaway with 500 entries, your likeness of winning is 1 out of 501. It does not matter if you've won already today or not, your chances stay the same. The system has no "memory".

It is however correct that it is increasingly unlikely to keep winning games but... This has no effect at all in single giveaways and should not worry you at all.

If you flip a coin 99 times in a row, and it comes up head 99 times, you still have a 50/50 shot at it being tails the next time.

I did probability in school but forgotten it now.

Regarding your question;

So if there are 10 giveaways, 9 with Bad Rats and one with Witcher III. Should I not enter the Bad Rats Giveaways (I know, insane not to enter Bad Rats), because this increases my total chance to win Witcher III, because if I only win 1 Bad Rats, it decreases my total chance to win Witcher III?

Considering if Bad Rats have 20 entries. I think entering Bad Rats and not winning Bad Rats increases your probability to win Witcher III. While winning Bad Rats will decrease you Witcher III chances but not by much because it was 20 entries anyway.

According to Gambler's fallacy what I said was wrong.

I've heard people winning 2 GAs in the same day. So if you see a Bad Rats and Witcher GAs, I'd say go for it since there is a possibility that you may win both!

GAs with less entries give you more chance to win since you are competing against less no. of people to get your name in the winning slot.

random clicky

Today I won 4 giveaways (invite only with low entries) :D

As the others have said, your chances of winning is not changed by how much you win, it is always 1/entries. Entering many giveaways increases your chances of winning, but the only way to decrease your chance of winning the game is to not enter all of the giveaways(still 1/entries chance, but if you lose one, you still have a chance at winning the other).

Yes as others have already stated, entering all the bad rats giveaways you want does not increase or decrease your chance of winning in the witcher 3 giveaway. The individual giveaways still have the same chance based on the number of entries for each one. What does decrease the more giveaways you win is the chance that you'll win all of them. Not the chance of the individual giveaways, but instead the chance that you'll win as many as you enter. The inverse is also true, the probability that you'll win a single giveaway increases the more giveaways you enter as most of us know experimentally regardless of the number of entries but of course the chance regarding a single giveaway is always based on it's number of entries.

you entering a bad rats giveaway doesn't affect the odds of you winning a witcher 3 giveaway in any meaningful way and is basically tied to that giveaway only. judging from the way you wrote your post, there isn't a "Probability God" that says "You won bad rats. Now i'm gonna make you wait longer until you win witcher 3."

you entering and winning a bad rats giveaway will not decrease your chance of winning witcher 3, and the only thing that will affect your odds is the total number of entries for a specific giveaway.

if, for the sake of argument, every single entry had exactly 1,000 entries, your odds will always be 1/1000. meaning, you're gonna win one for every 1,000 entries on average. of course, that doesn't mean that you must enter 1,000 to win one. A win could come after just 1 entry, and a second win after that could come after 1,999 entries. but probability dictates that ultimately, your win ratio will come out to be about 1/1000.

enter games you're most likely to play, and enter giveaways with low entries (e.g. favor those that start/end in an hour instead of 3 weeks) for the best odds. but that doesn't mean ignore those with high entries, cuz a chance is still a chance.

TL;DR:
enter games you wanna play, and create giveaways so you can enter higher-level giveaways (with less and less entries) to increase your odds!

Entering more giveaways makes more chance to win giveaway for you and not entering giveaways makes you to have less chances to win any giveaway. It is that simple. But to your question. if it somehow matters. The probability is still same with every toss of the coin. The probability of winning twice in the row or more is something else, but those two are different probabilites which in this question doesn't matter. No you will not get any more "lucky" by not entering "Bad Rats"

A more interesting problem arises on steamcompanion and I don't know if there is an exact solution to it.

The problem is: imagine you have a giveaway for 100 copies of the game and you can enter the giveaway multiple times. What is the probability you win a game if you have 100 entries and the total number of entries is, say, 300.
Obviously, if you assume, that each player has equal number of entries, you are winning (as there are only 3 actual entries), but in reality you can end up without the game if, say, every other player has just one entry.

Edit. Ok, having given it another thought. If every other player has just a single entry, then the probability of losing is:
(200/300)x(199/299)x(198/298)x...x(101/201) = 2.1776x10^(-23)
thus, the probability of winning is
1 - 2.1776x10^(-23) = pretty much close to one.

Similarly, I guess, you can calculate the probability of a different distribution of entries (which you never have). So, you can assume you are close to the average number of entries (what other option do you have?) and assume a normal distribution of the number of entries. This is going to provide an estimate for the expected chance of winning.

First of all, the chance that you will win a game just depends on the amount of entrys, right? So if you enter 50 giveaways, all with 500 entrys, the possibility to win a game, should be the same.

This is correct.

BUT: If you win just one giveaway, it's more unlikely that you will win a second one. And if you would win a second one, it's even more unlikely that you win a third one! Or am I wrong? Even though, logically, you should have the same chance on every giveaway...

This is incorrect. The chances in all giveaways remains the same. But, TOTAL chance of winning in 1 giveaway is more, than a total chance of winning all 500.

This leads me to my final question: Should I only enter giveaways with games I realy (realy) want to play? Well, I only enter Wishlist giveaways, but with 200+ wishlist games it's hard to say I realy want to play them all 100%.

Only if you want to give more chances to people who really want to play that games.

So if there are 10 giveaways, 9 with Bad Rats and one with Witcher III. Should I not enter the Bad Rats Giveaways (I know, insane not to enter Bad Rats), because this increases my total chance to win Witcher III, because if I only win 1 Bad Rats, it decreases my total chance to win Witcher III?

No, Bad Rats don't influent on chances in Witcher III. You would not win Witcher III anyway.

Basically the outcome of one event has no influence on any other individual events. As all others have said above me, bad rats giveaways will have no effect on your individual chances of winning witcher III, BUT they will increase your chances of winning A game, the more you enter.
To alter the thinking of the 99 coins landing tails, 50/50 to land next heads and tails right? But what was the odds of getting 100 in a row right at the start...really low! despite how low it is to predict a specific chain of outcomes, every coin toss is a 50/50. Its weird :)

I actually did some math on this in another discussion not so long ago:
HERE

I thought the logical way is to calculate the losing chance for each giveaway = (numberofentries-copiesgivenaway)/numberofentries
Multiply all of the chances of losing giveaways
subtract the product from 1 and you have the probability of winning at least 1 or more giveaways

However, this is not entirely correct if you enter the giveaways of the same game, because in SG setting once you win the game you cannot enter another giveaways/win another giveaway. But the % or probability of losing all the entered giveaways stays the same.

pssst...hey people... let him believe what he said! If we don't tell him the math behind it, he will only enter stuff he really wants!

In some sense, yes: if winning Bad Rats has a chance of 0.5 (50%), winning Witcher III has a chance of 0.01 (1%), then the combined event "winning Bad Rats AND winning Witcher III" really has a lower probability: 0.5*0.01=0.005 (0.5%). However the individual probabilities remain the same, not entering Bad Rats will not increase the chance of winning Witcher III. Although, a practical aspect: if you are short on points and can not enter a GA, you certainly will not win it.

In the short or medium term, luck also plays role. You may win far more or far less GAs than the real probabilities are. But in the long term, it is after all a matter of probabilities: your wins will be more or less the result of total GAs entered to average entries per GA division...