TheManaDrain.com
December 06, 2025, 12:00:46 pm *
Welcome, Guest. Please login or register.

Login with username, password and session length
News:
 
   Home   Help Search Calendar Login Register  
Pages: 1 [2]
  Print  
Author Topic: Probability and Magic  (Read 6131 times)
Elric
Full Members
Basic User
***
Posts: 213



View Profile
« Reply #30 on: December 07, 2005, 08:37:10 pm »

If you choose to mulligan, it doesn't matter whether or not FoW was in your opening hand -- since it doesn't affect the overall probabilty of drawing it in a new hand.  Your second probability gives the odds that you will have to mulligan once into FoW.

No- think about it this way: to find the probability that you find a Force given that you are willing to mulligan to 6, you should find 1- the chance that you find no Forces given that you are willing to mulligan to 6.  

The chance to find no Forces given that you are mulliganing to 6 is (1-P(7))*(1-P(6)).

When you do it out you find that the chance to find a Force is 1- (1-P(7))*(1-P(6))= P(7) + P(6) - P(6)*P(7)= P(7) + (1-P(7))*P(6) , which is the formula in my previous post.
Logged
Godder
Remington Steele
Administrator
Basic User
*****
Posts: 3264


"Steele here"

walfootrot@hotmail.com
View Profile WWW Email
« Reply #31 on: December 07, 2005, 11:41:10 pm »

I'm probably wrong, but I was assuming that I would work it out by 1-(P(7)*P(6)). I came to 67% by going 1-(0.6*0.55), which was wrong (should have been 0.65, not 0.55), and would come out at 0.61, not 0.67.

Quote from: JDizzle
If you choose to mulligan, it doesn't matter whether or not FoW was in your opening hand -- since it doesn't affect the overall probabilty of drawing it in a new hand. Your second probability gives the odds that you will have to mulligan once into FoW.

While that would be true if my mulligan decision was arrived at after the first hand was drawn, I'm assuming the mulligan decision was actually made prior to the start of the game i.e. mulligan until Force is drawn.
Logged

Quote from: Remington Steele
That's what I like about you, Laura - you're always willing to put my neck on the line.
Elric
Full Members
Basic User
***
Posts: 213



View Profile
« Reply #32 on: December 07, 2005, 11:50:35 pm »

I'm probably wrong, but I was assuming that I would work it out by 1-(P(7)*P(6)). I came to 67% by going 1-(0.6*0.55), which was wrong (should have been 0.65, not 0.55), and would come out at 0.61, not 0.67.

That works fine- the only difference is notation.  You're defining P(7) as the chance to have 0 Forces in a 7 card hand, while I'm defining P(7) as the chance to have >0 Forces in a 7 card hand (likewise for P(6)).  Thus where I use notation for (1-P(X)) you just use P(X).
Logged
Komatteru
Full Members
Basic User
***
Posts: 783

Joseiteki


View Profile
« Reply #33 on: December 08, 2005, 12:56:03 am »

Now that I look at it, there's a flaw in both models.  It is not as simple as merely computing it the way you have it, as that makes too many assumptions.
Logged
Elric
Full Members
Basic User
***
Posts: 213



View Profile
« Reply #34 on: December 08, 2005, 12:58:40 am »

Now that I look at it, there's a flaw in both models.  It is not as simple as merely computing it the way you have it, as that makes too many assumptions.

It really is that simple.
Logged
Komatteru
Full Members
Basic User
***
Posts: 783

Joseiteki


View Profile
« Reply #35 on: December 08, 2005, 01:08:58 am »

Not if you want it to mean something in the real world.
Logged
Elric
Full Members
Basic User
***
Posts: 213



View Profile
« Reply #36 on: December 08, 2005, 01:13:54 am »

Not if you want it to mean something in the real world.

Here's what it means: If you mulligan every 7 card hand that does not contain a Force of Will and keep every 6 card hand, whether it contains Force of Will or not, what is your chance to have a Force of Will in the hand that you end up with?  This may or may not be a good strategy to use but this mulligan strategy can be carried out by anyone.
Logged
Revvik
Basic User
**
Posts: 725


Team BC

Revvik
View Profile Email
« Reply #37 on: December 08, 2005, 01:54:07 am »

I really shoulld have paid attention when all of my math teachers said this would one day be relevant  Razz
Logged

http://www.thehardlessons.com/

I will break into your house while you aren't home and disguise myself as a chair. Then I will leave before you get home, but there will be a place at your table where I was a chair and you will wonder why there isn't a chair there. Then later I will leave the chair disguise on your doorstep and you will realize what has happened and you will be afraid all the time. Helter Skelter mother fuckers!
Godder
Remington Steele
Administrator
Basic User
*****
Posts: 3264


"Steele here"

walfootrot@hotmail.com
View Profile WWW Email
« Reply #38 on: December 08, 2005, 08:59:41 am »

Quote from: Revvik
I really shoulld have paid attention when all of my math teachers said this would one day be relevant  Razz

I don't think you missed much Very Happy.

That aside, JDizzle has reiterated my point earlier that there's more to it than just FoW or no i.e. another Blue card is needed to go with it, and mana as well. For example, below this thread is a thread for a Control Slaver primer. Following through to the decklist (available at SCG), we get a reasonably typical sort of Type 1 deck that actually runs FoW.

This deck has 23 Blue cards, of which 4 are FoW, and 25 mana sources, of which 15 produce Blue (+ Lotus, but it's a one-shot). We might reasonably assume that a hand with fewer than 2 mana sources (or one Blue source and Brainstorm) is a mulligan, as is any hand without permanent Blue mana). I realise there will be some exceptions (mainly involving Lotus + some other combination of cards), but I'm going to ignore those, as this is getting difficult enough as it is. What follows is a statement of some probabilities from that decklist, regarding the likely mulligans i.e. The approximate 7 card odds of:

Not drawing a permanent Blue source + a second mana source/Brainstorm – 12.4% (actually quite significant)
Not drawing any Blue cards at all – 2.7%
Not drawing FoW – 60%
Not drawing FoW + another Blue card – 61.6% (1.6% is small, but it's definitely not insignificant)

Putting those together, if we want to have FoW, another Blue card and 2+ mana sources/Brainstorm, one of which is a permanent Blue source, and we're not worried about the other cards, we say we get FoW + Blue card 38.4% of the time, and of those, 12.6% are useless for mana reasons i.e. only 87.4% of the 38.4% are viable, so we end up with 33.6%. By definition of what we're looking at, we don't have to worry about mulligans for too much mana (6+ mana sources), since 2 cards are spells, leaving 5 mana cards at most. If we're willing to mulligan to at least 6 to get a good hand, the odds of drawing FoW + Blue card are 32.7%, while the odds of viable mana are 82.3%, so the odds of the 6 card hand being viable are 26.9%. For a 5 card hand, the odds of FoW + Blue card are 26.4%, while the odds of viable mana are 74.6%, giving us 19.7%.

Putting the whole thing together now, I will now modify the original pre-game statement to say "I want a hand with FoW + Blue card + Blue mana source + some other mana source/Brainstorm, and I will mulligan to 6 to get it". 33.6% of the time, I will be successful on the first 7. Of the other 66.4% which mulligan to 6, 26.9% (of 66.4%) will be viable i.e. 17.9%, which takes us up to 51.5% (note that this is substantially lower than the 61% we were looking at above). If we are willing to mulligan to 5 in our pre-game statement, then of the remaining 48.5%, we will score 19.7%, which gives us 9.6% to add on, leaving a final total of 61.1%, for this particular deck.

This ignores any other possibilities of playable hands (Lotus-based or Welder-based, I'm guessing), as well as the possibility of the second Blue card and the second Mana source being Brainstorm (quite low, fortunately), so it's not exactly perfect, but it's somewhat more accurate than just looking at FoW, or, as JD put it, ignoring the real world. I can analyse other decks in the same way, but it gives us some idea to work with. I looked at some other decks, and a lot of the FoW decks had similar or fewer Blue cards (e.g. 3CC, Gifts were similar, TPS and Dragon were fewer), although a few were more (some Oath lists, counter-control e.g. mono-U, Tog). In any case, if desired, I can run the numbers over other Blue (Drain)-based decks, or over hypothetical sets of numbers for such decks – just post some numbers.
Logged

Quote from: Remington Steele
That's what I like about you, Laura - you're always willing to put my neck on the line.
unicoerner
Basic User
**
Posts: 47


View Profile
« Reply #39 on: December 08, 2005, 02:58:20 pm »

Someone said that there`s no interest at the match as a whole, but if you know i can only loose against a deck if it gets until turn x a card y, than you should be interested in this statistic.Cause if this happens over 80 percent of the times in a single matche, your chances of winning the whole match is exactly at 50 percent. If all players in this tourney would play that deck, your chances of going 6,0,0 are 1%.
This is hypotetical but it shows that the probability seen at the whole match is not that unimportant.
Logged

every critic is good critic
The Atog Lord
Administrator
Basic User
*****
Posts: 3451


The+Atog+Lord
View Profile
« Reply #40 on: December 08, 2005, 06:05:32 pm »

How the match as a whole works is unimportant if that is being used for a calculation after some portion of the match is decided (say, in game 3). A calculaton based on the match as a whole assumes that none of the games are yet decided -- once a game is decided, there is no point in using a metric that assumes it to be undecided.
Logged

The Academy: If I'm not dead, I have a Dragonlord Dromoka coming in 4 turns
Godder
Remington Steele
Administrator
Basic User
*****
Posts: 3264


"Steele here"

walfootrot@hotmail.com
View Profile WWW Email
« Reply #41 on: December 08, 2005, 09:12:01 pm »

Quote from: unicoerner
Someone said that there`s no interest at the match as a whole, but if you know i can only lose against a deck if it gets until turn x a card y, than you should be interested in this statistic. Cause if this happens over 80 percent of the times in a single match, your chances of winning the whole match is exactly at 50 percent. If all players in this tourney would play that deck, your chances of going 6,0,0 are 1%. This is hypothetical but it shows that the probability seen at the whole match is not that unimportant.

I'm not sure I follow what you're trying to say - can you clarify what you mean by the bolded phrase above?

Also, even if you get all favorable match-ups e.g. 70% across the board for 10 matches (7 rounds + top 8), multiplying it out often gives some pretty crappy odds of actually winning, even assuming you can lose one and draw one and still make top 8 (I get 5.8%). In other words, winning the whole thing takes a lot of luck, which we already knew.
Logged

Quote from: Remington Steele
That's what I like about you, Laura - you're always willing to put my neck on the line.
Pages: 1 [2]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!
Page created in 0.065 seconds with 21 queries.