Concept check 2. So if the trial comparing SuperStatin to placebo stated OR 0.5 95%CI 0.4-0.6 What would it mean? A) The odds of death in the SuperStatin arm are 50% less than in the placebo arm with the true population effect between 20% and 80%. Under 2.5 Goals is a popular football bet that literally means you are betting on there being less than 2.5 goals in a football match. That means you’d win this under 2.5 goals bet if the match you’d bet on produced no goals, one goal, or two goals. 2.5 can be calculated as (2.5. £10 stake) – £10 stake = £15 winnings. 1.25 can be calculated as (1.25. £10 stake) – £10 stake = £2.50 winnings. You can also use our bet calculator to help you calculate winnings. USE BET CALCULATOR. Decimal Odds Versus Fractional Odds.

1. What Does 5 2 Odds Mean In Horse Racing
2. What Does 5/2 Odds Mean
3. What Do 5/2 Odds Mean
4. What Does 5/2 Odds Mean In Horse Racing
5. What Is 5-2 Odds Mean

Written by Clay Smith

Idiot’s Guide

That’s right - I will be your guide. The good thing about having an idiot for a guide is that I have to make it simple to understand it myself, which means, hopefully, you will understand it as well.

Probability or Odds

Probability
Probability means the risk of an event happening divided by the total number of people at risk of having that event. I will use the example in a recent JAMA article. In a deck of 52 cards, there are 13 spades. So, the risk (or probability) of drawing a card randomly from the deck and getting spades is 13/52 = 0.25 = 25%. The numerator is the number of spades, and the denominator is the total number of cards.

Odds
Odds seems less intuitive. It is the ratio of the probability a thing will happen over the probability it won’t. In the spades example, the probability of drawing a spade is 0.25. The probability of not drawing a spade is 1 - 0.25. So the odds is 0.25/0.75 or 1:3 (or 0.33 or 1/3 pronounced 1 to 3 odds).

Moving back and forth
To go from odds to probability, simply take the numerator/(denominator + numerator). In the spades example, the odds of 1/3 is converted by taking 1/1+3 = 0.25 - and now we are back to probability. To go from probability to odds, simply take the numerator/(denominator-numerator). In the spades example, given that the probability of drawing a spade is 1/4, take 1/(4-1) = 1:3 odds or odds = 0.33.

Statistical Significance
If an odds ratio (OR) is 1, it means there is no association between the exposure and outcome. So, if the 95% confidence interval for an OR includes 1, it means the results are not statistically significant. Example, exposure to colored vs white Christmas lights was associated with an increase in jocularity score, OR = 1.2 (95%CI 0.98-1.45). Sorry, this is not statistically significant. Let’s just go with white lights…

Use
Either the OR or risk ratio (RR) could be used in many study types. However, only the OR can be used in case-control studies. Because in order to calculate the RR, one must know the risk. Risk is a probability, a proportion of those exposed with an outcome compared to the total population exposed. This is impossible in a case-control study, in which those who already have the outcome are included without knowing the total population exposed.

Risk Ratio

RR is a very intuitive concept. It is the probability (or risk) of one outcome over the probability (risk) of another. Let’s use a study we covered on JF to discuss this concept. Survival was lower in pediatric patients intubated during arrest compared with those not intubated: 411/1135 (36%) vs 460/1135 (41%). So, the RR is 36.2%/40.5% = 0.89. This means survival was reduced by a factor of 0.89 for pediatric arrest patients who were intubated during arrest vs. those who were not. As an example, if survival was expected to be 40%, then intubating during arrest would reduce it to: 40% x 0.89 = 35.6%.

Let’s do one more example. Supination-flexion (SF) vs hyperpronation (HP) to reduce nursemaid’s elbow was more likely to fail. The risk of failure with SF was 96/351 (27%) vs. 32/350 (9%) with HP. The RR was 3. This has a very intuitive meaning: risk of failure with SF was three times more likely than HP.

Odds Ratio

The OR is a way to present the strength of association between risk factors/exposures and outcomes. If the OR is <1, odds are decreased for an outcome; OR >1 means the odds are increased for a given outcome. Let’s look at the examples again and consider odds.

For pediatric arrest, the risk of survival if intubated during arrest was 411/1135 (36%) vs 460/1135 (41%) if not intubated. Let’s convert to odds and calculate an OR.

• Intubated: 411/1135-411 = 411/724 = 0.57 odds.

• Non-intubated: 460/1135-460 = 460/675 = 0.68 odds.

• So, the OR is 0.57/0.68 = 0.83.

Note, this is very close to the RR (0.89) but is a slight overestimate of the effect on the outcome. This is always the case with the OR compared to the RR - it overestimates the effect.

Take the example of supination-flexion vs hyperpronation for nursemaid’s. The risk of failure for SF was 96/351 vs. 32/350 with HP. Let’s convert this to odds.

• SF: 96/351-96 = 0.376 odds

• HP: 32/350-32 = 0.10 odds

• The OR is 0.376/0.10 = 3.7

Note, the OR overestimates the RR, which was 3. Although one could say the risk of failure using SF is 3 times greater than HP, one could not say, based on the OR, the risk was 3.74 times greater. The OR and RR are not the same. What could be said is that the odds of failure is 3.74 times greater.

Risk Ratio vs Odds Ratio

Whereas RR can be interpreted in a straightforward way, OR can not. A RR of 3 means the risk of an outcome is increased threefold. A RR of 0.5 means the risk is cut in half. But an OR of 3 doesn’t mean the risk is threefold; rather the odds is threefold greater. Interpretation of an OR must be in terms of odds, not probability. Again, the OR will always be an overestimate compared to the RR. However, the RR and OR will be similar for rare outcomes, <10%. But the OR increasingly overestimates RR as outcomes exceed 10%. This is easier to understand with an example.

Pretend a new vape, Vapalicious, is associated with cancer.

• 80/100 people who use it get cancer.

• 20/100 who don’t use it get cancer.

• The risk of getting cancer is 4 times greater in Vapalicious users. RR = 0.8/0.2 = 4

• Note how distorted the OR becomes in this example. OR = (80/20)/(20/80) = 16

What Does 5 2 Odds Mean In Horse Racing

What if Vapalicious rarely caused cancer?

• 5/1000 get cancer with Vapalicious vs 2.5/1000 for non-users.

• RR = 2.

• OR = 2 as well (actually 2.005)

• With rare outcomes, the RR and OR are very similar.

Why Does This Matter?

This matters because we often equate the OR and RR. Unwary researchers, reviewers, or news media might report a 16-fold increased risk of cancer from Vapalicious. In fact, there was a 4-fold increased risk of cancer from Vapalicous. Not that I plan to use Vapalicious (or any other vape), but a 16-fold vs 4-fold increase is a gross overestimation of the effect.

What Does the OR Mean?

So, what does an OR mean? Here it is in plain language.

• An OR of 1.2 means there is a 20% increase in the odds of an outcome with a given exposure.

• An OR of 2 means there is a 100% increase in the odds of an outcome with a given exposure. Or this could be stated that there is a doubling of the odds of the outcome. Note, this is not the same as saying a doubling of the risk.

• An OR of 0.2 means there is an 80% decrease in the odds of an outcome with a given exposure.

Summary

• Odds Ratio is a measure of the strength of association with an exposure and an outcome.

  • OR > 1 means greater odds of association with the exposure and outcome.

  • OR = 1 means there is no association between exposure and outcome.

  • OR < 1 means there is a lower odds of association between the exposure and outcome.

• If the 95% confidence interval for the OR includes 1, the results are not statistically significant.

• OR and RR are not the same.

• OR always overestimate RR, but…

• OR approximates RR when the outcome is rare but markedly overestimates it as outcome exceeds 10%.

References

1. The odds ratio by Bland and Altman, of Bland-Altman plot fame

2. Wikipedia aka source of all statistical knowledge

Easily the most popular type of betting for NFL football is “spread” betting or more commonly known as betting against the spread. Bettors who are new to NFL betting or betting in general may be a little confused with NFL spread betting, but it is pretty easy to understand once it is explained to you. We will explain what betting against the spread means below.

What is Betting Against The Spread?

For each NFL game the oddsmakers set a number of points in which the favored team is favored by. Bettors can then either choose for the favored team to win by more than the number of points set, or bet on the underdogs to lose by less than the number of points they are underdogs by or win the game straight up. For example, the spread could be set on the favored team at 6.5 points. This would mean in order for a bet on the favored team on the spread to win they would need to win by more than 6.5 points (7 or more) in order to win the bet. It also means that a bet on the underdog team would win if the underdogs lost by less than 6.5 points (6 or less) or won the game outright.

Example of NFL Spread Bet

Below is an example of what NFL spread betting would look like:

Matchup

• TeamsSpread
• Dallas Cowboys -2.5
• New York Giants +2-5

What Does 5/2 Odds Mean

The negative (-) sign indicates that the Cowboys are the favorites, while the positive (+) sign indicates that the New York Giants are the underdogs. With the spread set at 2.5 points, a bet on the Cowboys would mean that they would have to win by more than 2.5 points (3 or more) in order for you to win that bet. A bet on New York would mean that the Giants would have to either lose by 2.5 or less points (2 or less) or win the game outright in order for your bet to win.

Here is another example with a screenshot taken from 5Dimes.eu during Week 3 of the 2013 NFL season:

Here you can see that the Rams are +3.5, while the Cowboys are -3.5. So for this example the Cowboys are 3.5 point favorites, while the Rams are underdogs of 3.5 points. If you were to bet on St Louis you would need them to lose by 3 or fewer points or just win the game outright. If you were to bet on Dallas you would need the Cowboys to win by 4 or more points.

What Do 5/2 Odds Mean

If the Cowboys were to win by 3 points, lets say 30-27, any bets on the Rams +3.5 would win. Even though the Rams didn’t win the game they covered the spread of 3.5 points.

Now if the Cowboys were to win by 4 points, lets say 31-27, the Cowboys have covered the spread and anyone who wagered on Dallas would win their bets.

What Does 5/2 Odds Mean In Horse Racing

Other NFL Spread Betting Information

You may often notice that the spread is sometimes set at an even number such as 3, 6 , 10, etc. In this case if the favored team won by the exact amount set for the spread the bet would be pushed, and all bets would be returned. For example, if the Patriots were 3 point favorites and they won by a FG (3 points) than this would results in a push, meaning no matter which side you bet on you would get your money returned to you.

What Is 5-2 Odds Mean

The most common NFL spreads are usually set between about 2.5-10.5 points, but you will also almost always have games each week with spreads lower than 2.5 and higher than 10.5. In the event that the oddsmakers feel the game doesn’t need a spread, it would be set at 0 or what some call a pick’em (both teams are given even odds to win for this type of bet).

The odds given on the spread are usually -110 unless otherwise noted. It is not uncommon to see one side of the spread being -105, with the other side being -115. If you don’t see any odds listed for each side of NFL spreads you are supposed to assume the odds are -110 on each. Not sure how to read NFL betting odds? Check out our Sports Betting Odds guide.

Now that you know the basics of NFL spread betting you’ll want to check out our Sports Betting Strategy guide which has some great NFL strategy articles written by a professional bettor.