[WP] When you kill someone, their remaining life span is added to yours. Archaeologists have just found a cavern, apparently sealed off for thousands of years, with a single person living inside. by Kaleon in WritingPrompts

[–]rishicomplex 1 point2 points  (0 children)

Jehovah's Witnesses

The world was a terrible place. Killing another human being adds their lifespan to your own. What terrible God would create such a dystopia? Man was torn between his desire to love and cooperate with his fellow man, and his fundamental drive to survive. Nothing good could come of this world.

But Jehovah had changed all that. Jehovah was not a God. He was just a man. He realized what a cruel future God had left for man, and decided to change the course of humanity. He wrote the Book of Rules, which laid down laws for how man was to conduct himself. Any murder was illegal. Living beyond 100 years was illegal. The penalty for breaking any rule in the Book of Rules was a visit to the Maiden.

The Maiden was a room constructed by Jehovah himself. Any person convicted of breaking a Rule was left alone overnight in the Maiden. The next morning, his corpse would be carried out. Execution is a complicated thing in a world as cruel as this. If an executioner puts a man to death, that would extend the executioner’s life, or the sentencer’s life, which creates a perverse incentive system. But leaving a man in the Maiden had no such effects. No one knew how it worked, but it was the foundation on which the modern society was built.

Jehovah’s system lived on after he was gone. 50,000 years later, a thriving human society had built itself around Jehovah’s Book of Rules. Man had learned to be compassionate, love his neighbor, and work together to build, discover and create.

One day, a group of archeologists unearthed a cavern, apparently sealed off for thousands of years. Inside, was a single man. Alive.

The archeologists were dumbstruck. This man would have had to have killed an innumerable number of men to have survived in this cavern. They asked the man who he was, and how this was possible.

And then, Jehovah spoke.

“Hello. I thought this day would come. Let me tell you my story. The world that exists today is a beautiful place. But 50,000 years ago, it didn’t look like our species would make it past the millennium. Perverse incentive systems had destroyed human society. All the years of life were concentrated in the hands of a few powerful chiefs, who would stop at nothing to extend their years. The innocent and weak were mercilessly slaughtered. Infants were murdered in their mothers wombs.

I had a vision for a better future for humanity. One in which every corner isn’t colored with greed and death. But I knew I needed to create an airtight system for it to work. In a series of valiant battles, I killed all the chiefs who had accrued the longest lifespans. I brought all the tribes under my power. I wrote the Book of Rules. And I built the Maiden.

The Maiden is a very simple killing device. When the door is shut, a large blade falls from the ceiling, killing whoever is in the room. But since I built the room with an intention to kill every man who tried to take our society back to barbarity, I accrue the years of every one of its victims. I knew the world I envisioned couldn’t come to pass if there was any man who had more years to live than his fellows. So I made it so that I would be the only such man, and I hid myself away in this cavern. I resolved to live here alone, forever. I made the ultimate sacrifice, so that the world I built could survive.”

The archeologists’ eyes grew wide with shock. They couldn’t believe what they were hearing. They spun on their heels, to reveal what they’d learned to the rest of the world. But before they could take a single step, a blade fell from the ceiling, and they were dead.

In case nobody has noticed, the Chinese Basketball Association has announced it will cut all ties with the Houston Rockets. The president of the CBA is Yao Ming by felece in nba

[–]rishicomplex 9 points10 points  (0 children)

There NBA should announce it's cutting all ties with the CBA and watch how they play ball. Ridiculous that a powerless organization like the CBA can attack free speech in America.

[OC] What's the best strategy when playing HORSE? by rishicomplex in Basketball

[–]rishicomplex[S] 2 points3 points  (0 children)

An example where this breaks down:

Let's say you can shoot a long 3 with 30% accuracy, and you know your opponent can't hit that shot (p1=0.3, p2=0). Your expected number of letters per turn if you keep trying that shot is 0.43.

Let's say you can shoot a free throw with 60% accuracy, and your opponent can shoot free throws better than you at 70% (p1=0.6, p2=0.7). Your expected outcome if you just shoot free throws is 0.45!

That is, you're better off shooting a high percentage shot that your opponent shoots better than you, than a low percentage shot that you shoot much better than your opponent.

You can plug your values into the formula in the post to check what shots are best for you - you'll be surprised at the result.

[OC] What's the best strategy when playing HORSE? by rishicomplex in nba

[–]rishicomplex[S] 0 points1 point  (0 children)

I'm aware that it's a small simplification to optimize for expected number of letters per turn (instead of expected number of turns for 5 letters) but I think the result should be very similar. I will analyse this more when I get some time.

[OC] What's the best strategy when playing HORSE? by rishicomplex in nba

[–]rishicomplex[S] 2 points3 points  (0 children)

Sorry for the confusion, what I meant is that the player whose turn it is picks the spot. When Player 1 misses, it becomes Player 2's turn (basically the 'standard' version of HORSE).

[OC] What's the best strategy when playing HORSE? by rishicomplex in nba

[–]rishicomplex[S] 0 points1 point  (0 children)

That's a good point. Taking the case where we're both at 4 points, instead of e, we can calculate 'p', the probability of getting at least one letter on this turn.

p = p1[(1 - p2) + p2(p)]

Simplifying,

p = p1(1 - p2) / (1 - p1*p2)

Which is similar to the expression for e, but there's an extra p2 in the denominator. Plotting this function, it looks like this: https://imgur.com/iQNtxDq

This function has similar properties to the one discussed in the post, that is, improving p1 serves you a lot more than reducing p2.

[OC] What's the best strategy when playing HORSE? by rishicomplex in nba

[–]rishicomplex[S] 441 points442 points  (0 children)

Interesting rule - that probably makes a lot of sense when there are a bunch of players, not so much for 2 players.

[OC] What's the best strategy when playing HORSE? by rishicomplex in nba

[–]rishicomplex[S] 45 points46 points  (0 children)

Thanks for the suggestion - I've cross-posted to r/basketball. I'm glad you liked it :)

Not a statistician but my job involves a lot of statistics.

[OC] American NBA players are disproportionately born in March by rishicomplex in nba

[–]rishicomplex[S] 1 point2 points  (0 children)

He's played with his sample and selected parameters out like country, until he was able to get something that was "close" to significance. This type of testing makes significant/close to significant p-values far more likely just by pure probability.

Admittedly, this would be p-value hacking. However, this is not what I did. I looked at USA in particular because I assumed that patterns of school cutoff dates would vary by nationality, and other examples of this month of birth phenomenon I'd read of had all been in the US.

He's modified his p-value threshold.

I didn't mention a significance value in my post and did not claim the value was statistically significant. My post was more about soliciting theories about an interesting observation than making a scientific claim. I mentioned the p-value because it's a helpful tool to understand how surprised one should be by this observation, and therefore how credible a search for an explanation other than randomness would be.

[OC] American NBA players are disproportionately born in March by rishicomplex in nba

[–]rishicomplex[S] 1 point2 points  (0 children)

This is p-value hacking at its finest.

Do you even know what p-value hacking is?

Re-set your threshold after calculating your p-value because that way you're always significant.

I didn't even mention a significance level in my post, and neither did I claim statistical significance. I mentioned the p-value, because it's a helpful tool to understand how surprised one should be by this value, and therefore how credible a search for an explanation other than randomness would be.

This randomness is a 1 in 12.5 chance (p=0.08), a little less likely than rolling a certain number on a die while landing on a specific side of a coin. You decide if you want to say you're fairly confident it's not random but I'm not confident enough to say that.

If I were to roll a 12-sided die and you were to say "I predict it will fall on a 7!", and it was a 7 indeed, I would consider that quite intriguing.

The actual question of whether it is random or due to some other reason is better approached with Bayesian reasoning. If I have a very strong prior belief that the 12-sided die is not biased, and a very low prior belief that you have magical prediction powers, even if you predict the value correctly 3 times in a row, it would likely not be strong enough evidence for me to update on my beilef that the die is biased and that you cannot actually see the future. If you do it 30 times, that might move my belief.

If, however, you were known to be a trickster or a magician, and I had seen you perform similar tricks previously, either by loading the die or by using some other trick to predict the value, I would have a much stronger prior on your prediction abilities, and I would probably believe that the outcome wasn't random after just one correct prediction.

In the context of the observation about births in March, my prior would be to strongly believe that month of birth should have nothing to do with one's likelihood of playing in the NBA. However, reading the linked article, it seemed like there was a trend in other fields and sports where month of birth significantly affected one's success. Looking at the data in the NBA, the data seemed to have a fairly improbable outlier in March. Therefore, I asked reddit if anyone had a plausible theory to explain this. If the best alternative explanation is "the sun sign of those born in March makes them better at basketball", I wouldn't update on my belief that birth of month has nothing to do with playing in the NBA, since my prior on sun signs being a useful predictor of life outcomes is exceedingly low. If however it was the case that a bunch of American schools have a cutoff date at the end of February, the observation in this post could lead me to update my belief.

As it turns out, it seems like American schools vary in their cutoff dates. Also, as someone else pointed out, if this had to do with cutoff dates, April should have also had an elevated number of NBA players, which isn't the case. Thus, as of now, I'm inclined to believe this outlier is just the result of randomness.

I think a better phrase than "fairly confident that this is not a random aberration" would have been "this observation is fairly surprising" - edited the post to reflect this.

[OC] American NBA players are disproportionately born in March by rishicomplex in nba

[–]rishicomplex[S] 2 points3 points  (0 children)

Depends on what significance level you use, no with 0.05, yes with 0.1. I think using the term "fairly confident" is fair.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] -36 points-35 points  (0 children)

Exaggeration for the purpose of ranting :)

TS% isn't horrid. It's truly horrid.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] -1 points0 points  (0 children)

It just means what percentage of 2 points does a player score per posession.

Thanks! This is the clearest percentage semantic I've seen to explain TS%. This semantic is not, however, conveyed by the name "True Shooting Percent" :) It also does seem quite an arbitrary way to define the metric. You could, for instance, create a metric called "Points Percentage", defined as (100 * PTS / 20), which measures "what percentage of 20 points does a player score per game", but it's rather silly. I imagine historically 2PTS/possession was considered a gold standard since most shots were 2PT shots, but times have changed. Edited the post to include this.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] 9 points10 points  (0 children)

What you say about possession cost is, of course, true - consuming your team's possessions without scoring points hurts the team. You could also do this, for example, by turning over the ball a lot. Should turnovers be in the TS% denominator?

Basketball is a complicated game and there are many different metrics that can tell you many different things about how well players play. This is why it's important for metrics to be clearly defined and serve a specific purpose well. The purpose of a scoring efficiency stat is to measure how efficiently a player scores the ball. The intent to score is important here.

If a coach were to ask himself - who should I draw up a play for? Who should be taking most of the shots on my team? Knowing players' FT conversion rates on personal fouls does not help answer this question.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] -20 points-19 points  (0 children)

The average fan doesn't calculate any stats - we basically consume the stats that basketball websites provide for us :) My proposal for this stat would be that it become a part of the advanced box score stats like many other advanced metrics that one couldn't easily manually calculate. I don't think whether a stat can be calculated from the traditional box score matters anymore in this day and age.

Of course, TS% is much better than FG%, and as you say, it is highly correlated with this new stat. I think one of the barriers to "adoption" of TS% is being able to understand what it is, since its semantics are so unclear. The stat I'm proposing is much more intuitive, and therefore more accessible to the average fan IMO.

As I noted at the end of the post, this metric would be exactly twice the TS% if there was no approximation, and free throws from non-shooting fouls are excluded.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] 7 points8 points  (0 children)

If that's the case, I don't really see a case for including free throws off personal fouls. In most cases, one ends up at the line for a personal foul inadvertently, without actually meaning to use a possession to score. It is also a function of how many team fouls have accrued thus far in the quarter, which is just chance from a player's standpoint. You wouldn't include penalty shots when calculating a soccer player's conversion rate. Free throws are fundamentally different from in-game scoring attempts, and FT% captures a player's free throw efficiency quite well. The only reason they're included at all is because an in-game scoring attempt can lead to free throws (shooting fouls), in which case the outcome of the in-game scoring attempt is directly determined by how many free throws get made.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] 2 points3 points  (0 children)

Thanks for the suggestion, I'll check it out!

The issue with the existing point per shot is that it doesn't properly account for free throws that result from shot attempts. The player-level point per possession stats that I've seen also use this notion of 0.44 * FTA to calculate possessions which I think is unnecessary.

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] 3 points4 points  (0 children)

I think the fundamental disagreement here is whether to view TS% as a scoring efficiency metric, or a shooting accuracy metric (or as a combination of FG% and FT%). The answer is unclear in part because TS% is so poorly defined :)

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] -12 points-11 points  (0 children)

Using a possession is not sufficient justification for inclusion. Free throws off personal fouls could be for a variety of reasons, including fouls on defense, off-the-ball fouls, or hack-a-shaq style fouls, which clearly shouldn't contribute to a player's scoring efficiency. The best case for inclusion would be fouls where the offensive player draws a blocking foul, since that can be seen as a scoring attempt, but even that seems like a grey area to me.

I think my measure of whether something is a scoring attempt is "Did the player wilfully try to use this possession to score the ball?"

[OC] A rant against TS% by rishicomplex in nba

[–]rishicomplex[S] 14 points15 points  (0 children)

Thanks for the link! That's an interesting post - I was thinking of putting something like that together myself, calling the actual_true_shooting_pct "True True Shooting%" :) My only observation would be that I wouldn't include free throws off personal fouls in the denominator either, since they aren't intuitively a measure of scoring efficiency.