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"In the fragile reality of Discworld, and with the gods who like to play games, a million-to-one chance succeeds nine times out of ten." https://wiki.lspace.or

by dstick 4y ago

"In the fragile reality of Discworld, and with the gods who like to play games, a million-to-one chance succeeds nine times out of ten." https://wiki.lspace.org/Million-to-one_chance https://wiki.lspace.org/Million-to-one_chance

grumple 4y ago
If you have millions of ops per day, a million-to-one chance of something means you'll see it every day! And it only takes a few noisy customers to bring these issues to light.
- grayclhn 4y ago
  To be super pedantic, for one million ops it's closer to a 63% chance every day: Pr[something happens across 1_000_000 events] = 1 - Pr[nothing happens across 1_000_000 events] = 1 - Pr[nothing happens once]^1_000_000 ## assuming independence = 1 - (1 - Pr[something happens once])^1_000_000 = 1 - (1 - 1/1_000_000)^1_000_000 ≈ 1 - 0.378 = 0.632 It's still below 99% for 4 million ops.
  - Dylan16807 4y ago
    > for one million ops Okay, but they said millions. > It's still below 99% for 4 million ops. I find this misleading, because it's... 98%. Which completely undermines your argument. If something happens 98% of days, it's fine to call that "every day".
    - grayclhn 4y ago
      Dude, it was meant to be mildly educational, not an "argument."
      - Dylan16807 4y ago
        Then present it as a fun fact rather than as a correction? And I'm not trying to be mean but I think the way you phrased your last line is accidentally anti-educational. Your last line treats 1 million ops and 4 million ops as nearly equivalent, when the truth is that 1 million ops is far from "every day" while 4 million ops can easily be called "every day". And if you dislike the word "argument" pretend I said "point"? I think you're reading connotations into that word that I didn't intend.
        grayclhn 4y ago
        And yet... here you are, having applied that same mathematical principle to calculate the probability of observing a one-in-a-million event at least once in 4mil independent trials. That's probably something you already knew how to do, but if not, it's a pretty educational moment. ;) ps — "to be pedantic" means "fun fact" but sarcastically.
        Dylan16807 4y ago
        The bulk of your post was educational, but it was misleadingly shown as an answer to both "million" and "millions", when those two scenarios actually have very different answers. > ps — "to be pedantic" means "fun fact" but sarcastically. It means that, but also sets it up as a correction. But "millions" being "every day" was right all along.
- Agentlien 4y ago
  I saw this first hand when I was overseeing the crash reports during the release of an online AAA game. A game with millions of players. A fairly frequent crash bug was caused by a line with a comment explaining that it could theoretically cause a crash but that risk would be one in a million.
  - Dylan16807 4y ago
    How often did that code run? Even with one player, that would be too high for a per-frame risk...
    - Agentlien 4y ago
      It only happened on players connecting or disconnecting from the server. Unfortunately it was a server crash so once it did occur it discontented up to eight players.

by dstick 4y ago

grumple 4y ago

If you have millions of ops per day, a million-to-one chance of something means you'll see it every day! And it only takes a few noisy customers to bring these issues to light.

grayclhn 4y ago
To be super pedantic, for one million ops it's closer to a 63% chance every day: Pr[something happens across 1_000_000 events] = 1 - Pr[nothing happens across 1_000_000 events] = 1 - Pr[nothing happens once]^1_000_000 ## assuming independence = 1 - (1 - Pr[something happens once])^1_000_000 = 1 - (1 - 1/1_000_000)^1_000_000 ≈ 1 - 0.378 = 0.632 It's still below 99% for 4 million ops.
- Dylan16807 4y ago
  > for one million ops Okay, but they said millions. > It's still below 99% for 4 million ops. I find this misleading, because it's... 98%. Which completely undermines your argument. If something happens 98% of days, it's fine to call that "every day".
  - grayclhn 4y ago
    Dude, it was meant to be mildly educational, not an "argument."
    - Dylan16807 4y ago
      Then present it as a fun fact rather than as a correction? And I'm not trying to be mean but I think the way you phrased your last line is accidentally anti-educational. Your last line treats 1 million ops and 4 million ops as nearly equivalent, when the truth is that 1 million ops is far from "every day" while 4 million ops can easily be called "every day". And if you dislike the word "argument" pretend I said "point"? I think you're reading connotations into that word that I didn't intend.
      - grayclhn 4y ago
        And yet... here you are, having applied that same mathematical principle to calculate the probability of observing a one-in-a-million event at least once in 4mil independent trials. That's probably something you already knew how to do, but if not, it's a pretty educational moment. ;) ps — "to be pedantic" means "fun fact" but sarcastically.
        Dylan16807 4y ago
        The bulk of your post was educational, but it was misleadingly shown as an answer to both "million" and "millions", when those two scenarios actually have very different answers. > ps — "to be pedantic" means "fun fact" but sarcastically. It means that, but also sets it up as a correction. But "millions" being "every day" was right all along.
Agentlien 4y ago
I saw this first hand when I was overseeing the crash reports during the release of an online AAA game. A game with millions of players. A fairly frequent crash bug was caused by a line with a comment explaining that it could theoretically cause a crash but that risk would be one in a million.
- Dylan16807 4y ago
  How often did that code run? Even with one player, that would be too high for a per-frame risk...
  - Agentlien 4y ago
    It only happened on players connecting or disconnecting from the server. Unfortunately it was a server crash so once it did occur it discontented up to eight players.