Switch Theme:

Math of the +1 to first turn roll?  [RSS] Share on facebook Share on Twitter Submit to Reddit
»
Author Message
Advert


Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you:
  • No adverts like this in the forums anymore.
  • Times and dates in your local timezone.
  • Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance.
  • Email notifications for threads you want to watch closely.
  • Being a part of the oldest wargaming community on the net.
If you are already a member then feel free to login now.




Made in us
Regular Dakkanaut




Simple question for those of us not mathematically inclined:
How much more likely is the +1 to first turn (post-Chapter approved). Is it simply 1/6 more likely? As some numbers can no longer tie (double 6's) and others are now rerolled where previously would have lost (1 + 1 vs 2)

And so if it is 1/6 then assuming each player has a 50% chance of going first -
50 * 1/6 + 50 = 58ish%
vs
42ish for opponent?
   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

There are 36 total outcomes.

For the person with the +1 there are 21 outcomes that mean they win, 5 where they draw and 10 where they lose.

It would be 58.3% of winning if not for draws causing re-rolls, with re-rolls it comes closer to 66.5% for the player with the +1 and 33.5% for the opponant.

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Fixture of Dakka






Wait.. this just made me think of something.

All re-rolls happens before modifiers, does that means ties are always re-rolled because the +1 is a modifier?

   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

 Amishprn86 wrote:
Wait.. this just made me think of something.

All re-rolls happens before modifiers, does that means ties are always re-rolled because the +1 is a modifier?

No, the re-roll for tied rolls for deployment isn't the same as re-roll auras in game. Please don't give people on this website another thing to argue about (good job this isn't in YMDC).

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Fixture of Dakka






 mrhappyface wrote:
 Amishprn86 wrote:
Wait.. this just made me think of something.

All re-rolls happens before modifiers, does that means ties are always re-rolled because the +1 is a modifier?

No, the re-roll for tied rolls for deployment isn't the same as re-roll auras in game. Please don't give people on this website another thing to argue about (good job this isn't in YMDC).


I mean there are other things than aura, powers, abilities like No Escape etc... its not like i want arguing or anything, i thought about it and GW has been very consistent in this part of the rules at least.

Tho since it isnt YMDC i wont discuss it farther here.

   
Made in us
Screaming Shining Spear





USA

noooooooooooooooo......

I want another 9 page diatribe festival that DakkaDakka practices!!!!!!!

How dare you shut down this possible enterprise of joy!!!

 koooaei wrote:
We are rolling so many dice to have less time to realise that there is not much else to the game other than rolling so many dice.
 
   
Made in us
Regular Dakkanaut




Well we always have our mods to rely on to move this to YMDC :-)
   
Made in us
Fixture of Dakka






orkswubwub wrote:
Well we always have our mods to rely on to move this to YMDC :-)


Just made one, he was asking about math so lets leave it about math.
https://www.dakkadakka.com/dakkaforum/posts/list/747640.page

   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

 Amishprn86 wrote:
orkswubwub wrote:
Well we always have our mods to rely on to move this to YMDC :-)


Just made one, he was asking about math so lets leave it about math.
https://www.dakkadakka.com/dakkaforum/posts/list/747640.page

God dammit.

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Fixture of Dakka






Dont join in then lol, i mean IDK why it bothers you if your not there

   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

 Amishprn86 wrote:
Dont join in then lol, i mean IDK why it bothers you if your not there

It's cause YMDC always leaks into other boards, and it's especially bad when someone stubborn takes a side in something as ambiguous as this and starts throwing around their opinion like it's fact, derailing threads. But that's dakka for you.

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Regular Dakkanaut




Honestly I really only care about how this will be standardized at ITC - such as LVO
   
Made in us
Potent Possessed Daemonvessel





Re-roll of ties must come after modifiers as any other approach allows ties to happen as the final result.
   
Made in ca
Longtime Dakkanaut




*Current meatspace coordinates redacted*

Breng77 wrote:
Re-roll of ties must come after modifiers as any other approach allows ties to happen as the final result.
You keep your dirty logic out of this. Nothing but unvarnished opinion and shady rhetoric will carry the day here.

That said, I agree, and I don;t need YMDC to tell me what's what.

He knows that I know and you know that he actually doesn't know the rules at all. 
   
Made in au
Regular Dakkanaut




 mrhappyface wrote:
There are 36 total outcomes.

For the person with the +1 there are 21 outcomes that mean they win, 5 where they draw and 10 where they lose.

It would be 58.3% of winning if not for draws causing re-rolls, with re-rolls it comes closer to 66.5% for the player with the +1 and 33.5% for the opponant.

Then seize comes into it.
Also I got different numbers somehow.

I generally work with fractions so...
36 combinations. 5 we can rule out due to rerolls.
21/31 win. 67.8%
10/31 lose. 32.2%

That's before seizing

21/31 * 1/6 is the chance of your opponent seizing.
21/31-21/186 is your chance of winning. 56.5%. I think. Which means it's pretty close to even.

This message was edited 1 time. Last update was at 2018/01/05 10:53:12


 
   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

Zustiur wrote:

Then seize comes into it.
Also I got different numbers somehow.

I generally work with fractions so...
36 combinations. 5 we can rule out due to rerolls.
21/31 win. 67.8%
10/31 lose. 32.2%

Unfortunately, that's not how fractional chance works, you can't disregard the 5.

The calculation is:
21/36 + (5/36 * 21/36) + (5/36 * 5/36 * 21/36)... To win - the calculation is infinite in this case due to the chance of infinitely rolling a draw.

Then you do the same thing for lose but replace 21 with 10.

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in it
Perfect Shot Dark Angels Predator Pilot





Sesto San Giovanni, Italy

The appropriate math (correct me if I'm wrong, symbols are nasty with a single line of text) should be:

lim n→∞ [Σ(5/6^n*21/36)

TBH right now I don't know (if) how this limit can be solved, but there are tool online to crunch it if you want to have the real value.

I can't condone a place where abusers and abused are threated the same: it's destined to doom, so there is no reason to participate in it. 
   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

 Cybtroll wrote:
The appropriate math (correct me if I'm wrong, symbols are nasty with a single line of text) should be:

lim n→∞ [Σ(5/6^n*21/36)

TBH right now I don't know (if) how this limit can be solved, but there are tool online to crunch it if you want to have the real value.

lim n→∞ [Σ(5/36^(n-1)*21/36)]

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in gb
Regular Dakkanaut




 Cybtroll wrote:
The appropriate math (correct me if I'm wrong, symbols are nasty with a single line of text) should be:

lim n→∞ [Σ(5/6^n*21/36)

TBH right now I don't know (if) how this limit can be solved, but there are tool online to crunch it if you want to have the real value.


I think the probability of wining (with +1) it should be {lim n→∞ [Σ(5/36^n*21/36)]} + 21/36 ,

But logically it should tend towards 21/31, as any reroll will produce an identical chance of winning, losing and rerolling as the original roll. (assuming rerolls after modifiers and that the modifier is kept for all rerolls).

Which gives us ((5/6)*(21/31)) + ((1/6)*(10/31)) after seize the initiative: 0.5645 + 0.0538 = 0.61827, or about 62% chance of going first.
   
Made in us
Devestating Grey Knight Dreadknight




So ~12%? I'm happy someone is doing this, it's actually a pretty important decision for some players when it comes to list-building and deployment.

Hope is the first step on the road to disappointment. 
   
Made in gb
Ship's Officer



London

So having +1 on the roll makes you about twice as likely to go first.

It looks to me like having a small-ish number of units is still very helpfil in the CA scenarios. Good to know.
   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

Mandragola wrote:
So having +1 on the roll makes you about twice as likely to go first.

What makes you think that?

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Morphing Obliterator





 mrhappyface wrote:
There are 36 total outcomes.

For the person with the +1 there are 21 outcomes that mean they win, 5 where they draw and 10 where they lose.

It would be 58.3% of winning if not for draws causing re-rolls, with re-rolls it comes closer to 66.5% for the player with the +1 and 33.5% for the opponant.


Since you're already on top of the math, how does rolling to seize for the loser affect the percentages?

"In relating the circumstances which have led to my confinement in this refuge for the demented, I am aware that my present position will create a natural doubt of the authenticity of my narrative."  
   
Made in gb
Potent Possessed Daemonvessel





Why Aye Ya Canny Dakkanaughts!

TwinPoleTheory wrote:Since you're already on top of the math, how does rolling to seize for the loser affect the percentages?

Kaptin Blacksquigg already pumped out the math for that:
kaptin_Blacksquigg wrote:Which gives us ((5/6)*(21/31)) + ((1/6)*(10/31)) after seize the initiative: 0.5645 + 0.0538 = 0.61827, or about 62% chance of going first.

Ghorros wrote:
The moral of the story: Don't park your Imperial Knight in a field of Gretchin carrying power tools.
 Marmatag wrote:
All the while, my opponent is furious, throwing his codex on the floor, trying to slash his wrists with safety scissors.
 
   
Made in us
Morphing Obliterator





 mrhappyface wrote:
TwinPoleTheory wrote:Since you're already on top of the math, how does rolling to seize for the loser affect the percentages?

Kaptin Blacksquigg already pumped out the math for that:
kaptin_Blacksquigg wrote:Which gives us ((5/6)*(21/31)) + ((1/6)*(10/31)) after seize the initiative: 0.5645 + 0.0538 = 0.61827, or about 62% chance of going first.


This is what I get for lazily skimming the post, thanks!

"In relating the circumstances which have led to my confinement in this refuge for the demented, I am aware that my present position will create a natural doubt of the authenticity of my narrative."  
   
Made in gb
Sinewy Scourge




For anyone interested in the comparison with the old method. The chance of going first when the opponent could reroll seize, but the first to finish deploying went first was 69.4%, so a little better, but not as much as you may have thought.
   
Made in gb
Ship's Officer



London

 mrhappyface wrote:
Mandragola wrote:
So having +1 on the roll makes you about twice as likely to go first.

What makes you think that?


If you've got +1 there are 21 results out of 36 where you go first. The other guy has 10 results where he goes first. The person with +1 is therefore going to go first more than two times out of three.

Once you add in the chance of the loser or the first roll seizing the initiative, the chances converge slightly. It ends up with the person who finished deploying first getting first turn 62% of the time, vs 38% for the other guy. So more like 3/5 than 2/3.

anyway the point is that you're a lot more likely to go first if you finish deploying first. The +1 bonus might not feel all that huge but it actually is a big deal.
   
Made in nz
Dakka Veteran




Opponent can still reroll seize right?
   
Made in us
Fixture of Dakka






No. That was changed in CA

   
Made in us
Fixture of Dakka





You can entirely ignore re-rolls from drawn results. They have no impact on the final result. Nothing about what might have happened previous has any impact on rolling now, nor does anything in the future. Everything resets to a base state.

There aren't 36 possible results when two people each roll a d6 if they have to re-roll ties. Without a +1, there are 30 results. With it, there are 31.

It's like predicting a coin flip based on previous coin flips.

21/31 chance to win the initial roll. 5/6 chance of surviving a seize.

So the real answer is 56.45% chance to go first if you have the +1.

This message was edited 2 times. Last update was at 2018/01/15 22:39:33


"'players must agree how they are going to select their armies, and if any restrictions apply to the number and type of models they can use."

This is an actual rule in the actual rulebook. Quit whining about how you can imagine someone's army touching you in a bad place and play by the actual rules.


Freelance Ontologist

When people ask, "What's the point in understanding everything?" they've just disqualified themselves from using questions and should disappear in a puff of paradox. But they don't understand and just continue existing, which are also their only two strategies for life. 
   
 
Forum Index » 40K General Discussion
Go to: