ARAMs random generator is broken.

Linna Excel·Apr 16, 2014·1 votes·51 views

I have 35 champs available to me. I played 6 ARAM games today. 3 times, Sejuani came up. Including 2 games in a row. I was sick of playing her so I rerolled for Poppy on the last time.

Seeing her 2 games in a row is a 1 in 1225 chance. Now I'm not a statistician but seeing her as the result 3 times in 6 games is rather improbable.

Now, poppy is interesting for the reroll, because I tend to get her a lot as well. I was happy for the break, but objectively she's a champ I'm seeing too often.

It's bad enough I can't narrow the pool down, but for it to be streaky is worse. Especially when I never get to start a game with the champs I want to play. If you are going to keep it so that certain champs come up more often for certain people, then at least make it so we have some way to weight champs in our favor.

5 Comments

Hyrum GraffApr 16, 20141 votes

Randomness doesn't mean unlikely scenarios will never happen, it just means they're not likely to. But they do still happen, and when they do, we tend to have the reaction of "OMG it CAN'T be random, or that never would have happened!" But it does, because randomness is not consistency.

Edit: Also, remember that after you've gotten Sej once, the chance of getting her again is the exact same as the chance of getting her in the first place. It's not like it gets less likely that you'll get Sej, just because you got her in the last game.

Hyrum GraffApr 16, 20141 votes

On the other hand, it does seem to me like I'm often in games where both sides have similar team comps, so maybe there is some matching/it's not fully random. I just don't know.

Chaotic134Apr 16, 20141 votes

Last night I played against a Galio, Jayce, Velkoz, Nidalee, with a Vayne thrown in there, too. 4 them threw their poke at the same time and we never stood a chance.

Linna ExcelApr 16, 20141 votes

The thing is with programming, random isn't really random. It's pseudorandom. What this means is depending on what features of your programming language you use to construct your RNG, and how you use that language, your results may vary.

There's also things in programming you can do to prevent streakiness to keep people from asking about improbable but possible occurrences. I remember when DDO was released, its random number generator was borked and extremely streaky. Like rolling 8 or 9 ten times in a row on a virtual 1d20... For a large number of players.

In my example, I don't hate Sej, but she's not my favorite character and she's not particularly strong in ARAM. I stopped playing ARAM for awhile because I kept getting Poppy (maybe 3 or 4 times over a course of 12 matchs).

Now there's one thing to keep getting a character you want, it's completely different to keep getting characters you are impartial to at best, regret buying at worst. Ryze is another who comes up for me a lot.

So as I see it a few things are possible:

Assume the RNG is fine and leave it as is.
Weight characters so that ones that you've played more often are weighted a little less than normal. Especially if a character's frequency comes up more than a standard deviation for a player.
Check the past 10-20 games for each player and if a champ comes up twice during that time, he's removed from the pool for the next 10 games or so. The only exception to this would be for players with less than 20 champs available, but I'd still have something similar for them.

Linna ExcelMay 4, 20141 votes

And I just got Ryze 2 games in a row again.