# Questions tagged [odds]

The odds of an event is the ratio of the probability that the event will happen (p) to the probability that it will not happen (1-p).

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### GAMLSS BEINF Model s(x) coefficient log odds to odds interpretation. after logit link transformation

am fitting a BEINF beta inflated model using gamlss in r. The response is a continuous variable and I have a single continuous predictor covariate with a default smoothing term which is a cubic spline ...
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### Chances of four people being drawn together

There are eight people in a golf group. There is going to be a draw to split them into two groups of four. There are four people within the group who would like to be drawn together. What are the odds ...
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### What are the odds of 8 being drawn out of a group of 10 digits 5 times in 8 tries? [closed]

I am wanting to know the odds of something happening. What are the odds of 8 being drawn out of a group of 10 digits 5 times in 8 tries?
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### meanBEINF vs predict(model, type = "response') in BEINF GAMLSS. and determining odds of predictor variable coefficient

A variation of this question has been asked, but certain items remain unanswered - I am modeling the proportion of mortality (Prop) using a single continuous predictor variable which is temperature (...
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### How does Shapley obtain values in the probability space in tree classifiers?

By default, the Shapley values for a tree explainer (e.g. based on xgboost) are in the log odds space (where they are additive). However, there's a functionality in the package to obtain values in the ...
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### Transforming linear mixed model effect estimate to odds of a predetermined increment of change

I'm studying patient reported outcome in relation to treatment modalities in cancer. To assess the effect of a specific treatment (yes/no) on a specific outcome (normalised to 0-100, repeated measures ...
318 views

### Probability of Dice and Coin flips

A friend and I were disagreeing about how you calculate the probability for the following. Seeing as both of us aren't that strong in stats I figured I would come here. Sorry if this question is a ...
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### Have I found something new? (a formula for the odds of rolling at least one 1 when rolling an n-sided die n times)

The formula First, the formula I found for the odds of rolling at least one 1 when rolling an n-sided die n times: Math.round(1 - ( ((n-1)/n)^n -1 )*(n^n-1) )/n^n ...
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### How to add a correction to the parameters in logistic regression s.t. the decision boundary is corrected?

Sometimes we would like to correct the decision boundary of a pretrained logistic regression model $p(y_{temp}=1|x)$, for example by multiplying by a prior in pursuit of adapting better to the ...
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### What is the meaning of “3 to 1 odds against success”?

I came across this passage while reading about forecasts, but I am not sure if my interpretation of the odds below is correct. I am interpreting it as there a 75% of success, is that correct? In ...
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### Interpreting logistic regression coefficients of a variable overall and levelwise

Context Let Y be a logical vector and X1 a factor with 3 levels. Since Y is binary, logistic regression is used. ...
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### Multi site data, logistic regression

I have a data from two hospitals and wanted to perform cox ph modeling on them. Prior to doing that, I ran logistic regression on the hospital variable (0-hospital A, 1 hospital B) with all the ...
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### Probability of Lottery (TOTO)

I have just a question about probability/odds and combinatorics here. Context: In Singapore, we have a lottery called Toto. Buyers can pick at least six numbers, from 1 to 49. Group 1 prize odds is 1 ...
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### Odds to probability transformation

The odds are defined as $\omega = \frac{\pi}{1-\pi}$, where $\pi$ is the probability of some event. How can it be shown that the back-transformations is given via $\pi = \frac{\omega}{1 + \omega}$?
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### Why are log odds modelled as a linear function?

I think I already have the answer, however, I wish for some confirmation that I am not missing anything here. This sort of asks the same thing, but I want to double-check. Logistic regression can be ...
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### Textmining classification: Using odds to generate a composite score

I have a classification task where i am predicting if someone owns a cat or not (made up example). I have columns which contain answers to questions in free form. For example "I own a feline cat&...
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### Can we estimate the propotion of outcome (binary) variance explained by multiple predictors using summary statistics only?

A toy example: We aim to predict the onset of stroke by body weight and age. We know that: 1-SD increment of weight increases the odds of stroke by 20% i.e. standardized coefficient of regression ...
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### What happens to American odds when the point spread gets further from zero? [closed]

I am learning about American odds (moneyline odds) and point spreads. In Chapter 2 of Sports Betting for Dummies, I see: When the point spread on a game gets further from zero, the two moneyline bets ...
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### Are odds relevant for continuous random variables?

The odds of probability $p$ is $\frac{p}{1-p}$. Odds provide a measure of the likelihood of a particular outcome, calculated as the ratio of the number of events that produce the outcome to the number ...
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### Can we maximize the log of the odds instead of log of the probability?

As above. This question relates to all optimization formulations in statistics.
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### Calculating Variance of the LogOR for within subjects studies for a meta-analysis [duplicate]

I would like to add to a meta analysis both studies with between and within subject design, but for the latter I don't know how to calculate the variance of the logOR. I found an answer here But what ...
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### Interpret the AIC in logistic regression

I'm doing logistic regression in R with binary data (0's and 1's), sample size around 300 : Predicting 1 target variable (varp) If I use one independent variable ( varx), it's significant (p 0.03, the ...
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### Odds to probabilty and back- I am not getting same value!

I am using following formulae to convert between odds and probability: probability = odds / (1+odds) odds = probability / (1-probability) I am doing following ...
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### How to get log odds from these results of logistic regression

I have performed logistic regression (using 'LOGIT') on variables from titanic dataset. The formula used is: survived ~ age + sex + pclass I have obtained results ...
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### Does the Elo system work with different expected value functions?

In many Elo rating systems, the expected value for player A with rating $R_A$ against an opponent with rating $R_B$ is $$E_A = \frac1{1+10^{(R_B - R_A)/c}}$$ The original Elo system is based on a ...
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### Calculating probability from multivariate logistic regression using odds instead of log odds

Question: is there a way to calculate probability from odds ratios instead of log odds ratios? I am trying to wrap my head around calculating probability from a multivariate logistic regression model ...
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### Interpreting Odds Ratio (in an Interaction)

I need advice on the correct interpretation of an odds ratio of an interaction term. Both the mixed-effect logistic regression output is below as well as the predicted odds values, which I calculate ...
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### How do interpret the odds ratio of a coefficient?

Building a logistic model with odds ratios, I have run into question I simply cannot figure out. Normally, the odds ratio of a coefficient equals how much the odds of y = 1 multiplies when x ...
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### How to create a hypothesis test comparing two odds? [closed]

Let's say I have two odds, how would I conduct a hypothesis test with a 5% significance level?
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### Player based betting odds VS analysis based odds

there are two kinds of betting sites Player based odds sites (thunderpick.com , csgopositive.com , ...) analysis based odds sited (1xbet , bwin , and almost all of the huge betting sites) when you ...
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### How to calculate probability of rain today given today percentage

Given this: If the probability of rain in a given day is 0.65, what are the odds that it will rain today ? Would I setup as P(A) = it rains 65% But with the missing today forecast, what and how would ...
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### Is a very large odds ratio from a contingency table an issue?

I computed an odds ratio from a contingency table (exposure/disease). My odds ratio ended up being 3329.044 which is ridiculously large. The reason it is large is because the prevalence of the disease ...
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### Odds Ratio for Interaction Terms in GenLin in SPSS

I have a generalized linear model using SPSS to determine the relationship between certain variables (sex, race/ethnicity, geographical area, etc.) and whether or not they use a computer. Also, we ...
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### Interpreting the Odds Ratio of a logistic regression model

I'm currently working on building a logistic regression model with the aim of predicting whether a given stock index will go up or down the following day. The table below shows the 3 models I've ran ...
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### Double odds of one outcome, what should happen to the other outcomes?

When you have a binomial outcome, doubling the odds of one outcome halves the odds of the other outcome. E.g. if I have a weighted coin that doubles the odds of heads, it halves the odds of tails. If ...
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### Determining the winner of a match given nothing but each team's winning percentage

Team A and Team B are playing a game against each other. This is the only information we have for each team: Team A has won 65% of their games this year Team B has won 59% of their games this year ...
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### Are they cheating?

I'm trying to determine the probability that three students cheated on a recent exam. In a nutshell: What are the odds that three students sitting next to each other in a class of 22 could select (...
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### How to interpret this logistic regression question?

This is from a DataCamp course. Try as I might, I can't seem to figure out how to break this down into explanations: The fitted coefficient β^1 from the medical school logistic regression model is 5....
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### Estimating/translating odds ratio for different percentile intervals

I have a question regarding a translation in odds ratio curve OR(x). More specifically, let's say we have an OR(x) which we get using logistic regression. We look at the interval bounded with 25% and ...
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### Chances, clarification [duplicate]

What are the odds Ive met my other half? Thing is I already know I have with this undeniable experience we had when our souls actually collided together as we were one. I just want to know what ...
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### What probability or weight should I assign to X so that it has a Y% chance of being one of the 6 items selected out of a population of 12?

I have a population of 12 items, let's call them A through L. I'm going to be drawing 6 of those items out of the population without replacement. So you can't choose the same item twice. What I know ...
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### Generate odds ratios across deciles / quantiles of an indpendent variable

With reference to the following figure from Bellomo et al., 2011: How exactly are the odds ratios across the deciles 'referenced against the 4th decile' calculated? My initial impression is that a ...
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### Multiple non-independent tests, how to determine post-test odds

Let's say a patient receives two biomarker tests to help with diagnosis of a disease. Each test measures a different mechanism of the disease, but these two mechanisms are not independent, so the ...
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### Betting odds with team win and draw

So a game can have 3 outcomes: Team 1 wins: 36% chance. Payout is 2.15 Team 2 wins: 34% chance. Payout is 2.45 Game is a draw: 30% chance. Payout is 2.66 How should I be thinking about making one or ...
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### What is the relationship between the risk ratio and the weight of evidence? [duplicate]

I've been reading about risk ratios as typical measures in clinical settings. In the finance and credit literature, there is the weight of evidence (WoE) measure that is used to encode and study ...
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### When Can I say odds ratio is important to analyze my data

Lets say in my data if I generate odds ratio between 2 variable A and B and get that the odds ratio is 2-5 is that a good thing to dive deep further or should I move to other relations .
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### What are the selection odds

If 30 ice-cream sticks are numbered 1-30 and placed in a bowl, what are the odds that when picking two at a time, and then returning them to the bowl, any random pair will never be picked?
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### Log odds Standard Error?

I am reading a paper on how the authors calculate the variance/standard deviation of what appears to be log(odds). The paper is a medical paper (Discontinuation of Oral Antivirals in Chronic Hepatitis ...
I am wondering what the correct way of interpreting an odds ratio is. For example, suppose we have that the probability of success is $p=0.8$. Then, the odds ratio is:  \frac{p}{1-p} = \frac{0.8}{0....