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Post by cityofchamps on Apr 28, 2015 23:33:25 GMT -5
I know this is a weird time to post about the NBA Draft at this point in time, but I wanted to make a point that I just realized over the past month or so. There is actually an effective system in place against NBA teams completely tanking. That is why they have the lottery. It isn't perfect or anything, but it actually has some pretty darn effective contingencies against teams who try to lose and lose for the worst record to get the #1 overall pick.
I am sure all of you who follow the NBA know this much that the team with the worst overall record gets the highest chances for the #1 overall pick at .250 (or 1/4 of a shot). However, that team ALSO has the most (and more) chance of getting the #4 overall pick (at .358). That is why you RARELY see the team with the worst record get the #1 overall pick. In fact, since the current system has been in place (since 1990), there has only been two teams that have had the worst overall record go on to win the lottery with the most chances to get the #1 overall pick and that was in 2004 with the Orlando Magic and they selected Dwight Howard and in 1990 with the New Jersey Nets and they selected Derrick Coleman.
True, there are teams that have tanked this season (Minnesota, New York, Philly, LA, etc.), but that does not guarantee them a top pick in the draft. more than likely, a team with the 5th record or worst will earn the #1 overall pic. It has happened 12/25 total times since this system was put in place.
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Post by Juggs on Apr 28, 2015 23:53:37 GMT -5
Well, the lottery does help prevent tanking theoretically, but it's not as effective as you claim. I'm going to tackle this argument from a game theory point of view, since I haven't watched the NBA for years and don't know much about it.
The assertion made is that purposely losing games is not a statistically significant method of earning the #1 pick.
To test this, all we need is the theoretical sample proportion for earning the pick. Remember that the assertion doesn't distinguish the second pick from the fourth pick any more than it does the fourteenth. It only revolves around the odds of getting numero uno.
To get the sample proportion, we would take the difference of the first and second pick odds (25% to 19.9%). The difference is our sample proportion, 5.1%, or .051. To create the test statistic, we take our null value (50% or .5) minus the actual proportion (.051). Divide by standard deviation of the proportions (.226), to get your test statistic of .225.
Now we have to standardize that and take the inverse of the inferred percentage. We can do this with a simple z-score table that anyone can look up online. A z-score of .225 happens to be .595 or 59.5%. The inverse (complimentary) percent is 40.5% which gives a p-value of -.15.
The p-value is negative, which implies that any significance would be greater and therefore, we reject the assertion that tanking doesn't help get the #1 pick. There is a significant difference between owning the best chance and the second best chance. Whether or not this actually happens in practice is irrelevant. What the math says is that the best tactic to earn the #1 pick is to tank, even if it also raises the odds of gaining other picks to slightly higher levels.
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Post by cityofchamps on Apr 29, 2015 12:20:39 GMT -5
Well, the lottery does help prevent tanking theoretically, but it's not as effective as you claim. I'm going to tackle this argument from a game theory point of view, since I haven't watched the NBA for years and don't know much about it. The assertion made is that purposely losing games is not a statistically significant method of earning the #1 pick. To test this, all we need is the theoretical sample proportion for earning the pick. Remember that the assertion doesn't distinguish the second pick from the fourth pick any more than it does the fourteenth. It only revolves around the odds of getting numero uno. To get the sample proportion, we would take the difference of the first and second pick odds (25% to 19.9%). The difference is our sample proportion, 5.1%, or .051. To create the test statistic, we take our null value (50% or .5) minus the actual proportion (.051). Divide by standard deviation of the proportions (.226), to get your test statistic of .225. Now we have to standardize that and take the inverse of the inferred percentage. We can do this with a simple z-score table that anyone can look up online. A z-score of .225 happens to be .595 or 59.5%. The inverse (complimentary) percent is 40.5% which gives a p-value of -.15. The p-value is negative, which implies that any significance would be greater and therefore, we reject the assertion that tanking doesn't help get the #1 pick. There is a significant difference between owning the best chance and the second best chance. Whether or not this actually happens in practice is irrelevant. What the math says is that the best tactic to earn the #1 pick is to tank, even if it also raises the odds of gaining other picks to slightly higher levels. Holy, f**k You must be a statistics major. I am taking a statistics class right now and I only understood about half of what you are talking about. I know about z-scores, test statistics, etc., but I have no idea where you got the numbers from.
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Post by Juggs on Apr 29, 2015 12:33:03 GMT -5
Well, the lottery does help prevent tanking theoretically, but it's not as effective as you claim. I'm going to tackle this argument from a game theory point of view, since I haven't watched the NBA for years and don't know much about it. The assertion made is that purposely losing games is not a statistically significant method of earning the #1 pick. To test this, all we need is the theoretical sample proportion for earning the pick. Remember that the assertion doesn't distinguish the second pick from the fourth pick any more than it does the fourteenth. It only revolves around the odds of getting numero uno. To get the sample proportion, we would take the difference of the first and second pick odds (25% to 19.9%). The difference is our sample proportion, 5.1%, or .051. To create the test statistic, we take our null value (50% or .5) minus the actual proportion (.051). Divide by standard deviation of the proportions (.226), to get your test statistic of .225. Now we have to standardize that and take the inverse of the inferred percentage. We can do this with a simple z-score table that anyone can look up online. A z-score of .225 happens to be .595 or 59.5%. The inverse (complimentary) percent is 40.5% which gives a p-value of -.15. The p-value is negative, which implies that any significance would be greater and therefore, we reject the assertion that tanking doesn't help get the #1 pick. There is a significant difference between owning the best chance and the second best chance. Whether or not this actually happens in practice is irrelevant. What the math says is that the best tactic to earn the #1 pick is to tank, even if it also raises the odds of gaining other picks to slightly higher levels. Holy, f**k You must be a statistics major. I am taking a statistics class right now and I only understood about half of what you are talking about. I know about z-scores, test statistics, etc., but I have no idea where you got the numbers from. I too am taking stats right now. I have my final exam on Thursday. This was a nice problem set to work on. edit: not majoring in stats. I'm just taking it because they make me. It's so stupid. I can't wait to forget everything by fall haha.
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Post by Jindred on Apr 29, 2015 14:42:32 GMT -5
The NHL also has a draft lottery where the top 4 teams get a shot at the #1 pick. This has lead to the Oilers draft #1 overall pick 4x in 6 years. This year in the NHL draft a once in a decade player is coming out so a few teams did bomb, namely the Buffalo Sabres and Pheonix Coyotes.
Now yea the lottery is a little bit better than what the NFL has in place as far as a tanking prevention, but still you get bottom 4 and you have a shot at the #1 overall pick.
The NHL right now is considering a new way to prevent tanking. Once a team is mathematically eliminated from playoff contention they start receiving points every time they win a game. The team with the most points after being mathematically eliminated gets the #1 overall pick. This promotes teams to work their ass off even after they no longer have a shot at the playoffs.
This could theoretically lead to teams tanking the first half of the season to get eliminated quicker if they feel they have no shot at making the playoffs. But it would lead to excitement once the teams are eliminated.
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Post by 101mitch on Apr 29, 2015 15:39:48 GMT -5
Teams still tanked this year, so even if this means tanking doesn't help, it is still happening.
I am personally all for tanking. If you believe that is the best strategy, go for it.
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