Does anyone know how NBA.com calculates pace adjusted stats? When pulling data, there is a pace_adjust option -- I'm wondering how that differs from non pace adjusted. Conceptually I understand what it means, just wondering how they account for it. Thanks!
Pace adjusting is as simple as normalization. The rationale behind it is quite simple: To fairly compare two NBA teams, we have to normalize the number of game opportunities that they generate against common ground. Otherwise, it would be impossible to properly correlate game statistics between them. For example, that would be the case if you'd want to compare statistics coming from a fast-paced team like the Los Angeles Lakers (3rd highest pace in 2021/22 at 100.36) and a slow-paced team like the New York Knicks (bottom last pace in 2021/22 at a mere 95.11).
Formally, if M is a generic NBA player/team's metric, then its pace-adjusted value M_adj would be:
s = pace_lg / pace_tm
M_adj = s*M
where pace_lg and pace_tm are the league's and the team's pace, respectively. To calculate the league's pace (LP), we simply have to average the number of possessions of all NBA teams and adjust that for a full game (or 48 minutes). Instead, to calculate a team's pace (TP), we follow a slightly different formulation: We average the number of possessions of the team with their opponent's, and only then adjust for 48 minutes. Why? Because LP can be interpreted as a census of all possessions, whereas TP is a sample from the population of all possessions.
For practical use of pace adjusting, you can check out my breakdown of the player efficiency rating (PER).
P.S.: When I say "we" I refer to ESPN's J. Hollinger formulation of pace adjusting in the NBA. Different organizations or sports analytics services may slightly alter its computation.
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I run an infectious disease spread model similar to "VIRUS" model in the model library changing the "infectiousness".
I did 20 runs each for infectiousness values 98% , 95% , 93% and the Maximum infected count was 74.05 , 73 ,78.9 respectively. (peak was at tick 38 for all 3 infectiousness values)
[I took the average of the infected count for each tick and took the maximum of these averages as the "maximum infected".]
I was expecting the maximum infected count to decrease when the infectiousness is reduced, but it didn't. As per what I understood this happens, because I considered the average values of each simulation run. (It is like I am considering a new simulation run with average infected count for each tick ).
I want to say that, I am considering all 20 simulation runs. Is there a way to do that other than the way I used the average?
In the Models Library Virus model with default parameter settings at other values, and those high infectiousness values, what I see when I run the model is a periodic variation in the numbers three classes of person. Look at the plot in the lower left corner, and you'll see this. What is happening, I believe, is this:
When there are many healthy, non-immune people, that means that there are many people who can get infected, so the number of infected people goes up, and the number of healthy people goes down.
Soon after that, the number of sick, infectious people goes down, because they either die or become immune.
Since there are now more immune people, and fewer infectious people, the number of non-immune healthy grows; they are reproducing. (See "How it works" in the Info tab.) But now we have returned to the situation in step 1, ... so the cycle continues.
If your model is sufficiently similar to the Models Library Virus model, I'd bet that this is part of what's happening. If you don't have a plot window like the Virus model, I recommend adding it.
Also, you didn't say how many ticks you are running the model for. If you run it for a short number of ticks, you won't notice the periodic behavior, but that doesn't mean it hasn't begun.
What this all means that increasing infectiousness wouldn't necessarily increase the maximum number infected: a faster rate of infection means that the number of individuals who can infected drops faster. I'm not sure that the maximum number infected over the whole run is an interesting number, with this model and a high infectiousness value. It depends what you are trying to understand.
One of the great things about NetLogo and some other ABM systems is that you can watch the system evolve over time, using various tools such as plots, monitors, etc. as well as just looking at the agents move around or change states over time. This can help you understand what is going on in a way that a single number like an average won't. Then you can use this insight to figure out a more informative way of measuring what is happening.
Another model where you can see a similar kind of periodic pattern is Wolf-Sheep Predation. I recommend looking at that. It may be easier to understand the pattern. (If you are interested in mathematical models of this kind of phenomenon, look up Lotka-Volterra models.)
(Real virus transmission can be more complicated, because a person (or other animal) is a kind of big "island" where viruses can reproduce quickly. If they reproduce too quickly, this can kill the host, and prevent further transmission of the virus. Sometimes a virus that reproduces more slowly can harm more people, because there is time for them to infect others. This blog post by Elliott Sober gives a relatively simple mathematical introduction to some of the issues involved, but his simple mathematical models don't take into account all of the complications involved in real virus transmission.)
EDIT: You added a comment Lawan, saying that you are interested in modeling COVID-19 transmission. This paper, Variation and multilevel selection of SARS‐CoV‐2 by Blackstone, Blackstone, and Berg, suggests that some of the dynamics that I mentioned in the preceding remarks might be characteristic of COVID-19 transmission. That paper is about six months old now, and it offered some speculations based on limited information. There's probably more known now, but this might suggest avenues for further investigation.
If you're interested, you might also consider asking general questions about virus transmission on the Biology Stackexchange site.
Currently I'm building my monitoring services for my e-commerce Server, which mostly focus on CPU/RAM usage. It's likely Anomaly Detection on Timeseries data.
My approach is building LSTM Neural Network to predict next CPU/RAM value on chart trending and compare with STD (standard deviation) value multiply with some number (currently is 10)
But in real life conditions, it depends on many differents conditions, such as:
1- Maintainance Time (in this time "anomaly" is not "anomaly")
2- Sales time in day-off events, holidays, etc., RAM/CPU usages increase is normal, of courses
3- If percentages of CPU/RAM decrement are the same over 3 observations: 5 mins, 10 mins & 15 mins -> Anomaly. But if 5 mins decreased 50%, but 10 mins it didn't decrease too much (-5% ~ +5%) -> Not an "anomaly".
Currently I detect anomaly on formular likes this:
isAlert = (Diff5m >= 10 && Diff10m >= 15 && Diff30m >= 40)
where Diff is Different Percentage in Absolute value.
Unfortunately I don't save my "pure" data for building neural network, for example, when it detects anomaly, I modified that it is not an anomaly anymore.
I would like to add some attributes to my input for model, such as isMaintenance, isPromotion, isHoliday, etc. but sometimes it leads to overfitting.
I also want to my NN can adjust baseline over the time, for example, when my Service is more popular, etc.
There are any hints on these aims?
Thanks
I would say that an anomaly is an unusual outcome, i.e. a outcome that's not expected given the inputs. As you've figured out, there are a few variables that are expected to influence CPU and RAM usage. So why not feed those to the network? That's the whole point of Machine Learning. Your network will make a prediction of CPU usage, taking into account the sales volume, whether there is (or was) a maintenance window, etc.
Note that you probably don't need an isPromotion input if you include actual sales volumes. The former is a discrete input, and only captures a fraction of the information present in the totalSales input
Machine Learning definitely needs data. If you threw that away, you'll have to restart capturing it. As for adjusting the baseline, you can achieve that by overweighting recent input data.
I have a project that consisted of transmitting data wirelessly from 15 tractors to a station, the maximum distance between tractor and station is 13 miles. I used a raspberry pi 3 to collect data from tractors. with some research I found that there is no wifi or GSM coverage so the only solution is to use RF communication using VHF. so is that possible with raspberry pi or I must add a modem? if yes, what is the criterion for choosing a modem? and please if you have any other information tell me?
and thank you for your time.
I had a similar issue but possibly a little more complex. I needed to cover a maximum distance of 22 kilometres and I wanted to monitor over 100 resources ranging from breeding stock to fences and gates etc. I too had no GSM access plus no direct line of sight access as the area is hilly and the breeders like the deep valleys. The solution I used was to make my own radio network using cheap radio repeaters. Everything was battery operated and was driven by the receivers powering up the transmitters. This means that the units consume only 40 micro amps on standby and when the transmitters transmit, in my case they consume around 100 to 200 milliamps.
In the house I have a little program that transmits a poll to the receivers every so often and waits for the units to reply. This gives me a big advantage because I can, via the repeater trail (as each repeater, the signal goes through, adds its code to the returning message) actually determine were my stock are.
Now for the big issue, how long do the batteries last? Well each unit has a 18650 battery. For the fence and gate controls this is charged by a small 5 volt solar panel and after 2 years running time I have not changed any of them. For the cattle units the length of time between charges depends solely on how often you poll the units (note each unit has its own code) with one exception (a bull who wants to roam and is a real escape artist) I only poll them once or twice a day and I swap the battery every two weeks.
The frequency I use is 433Mhz and the radio transmitters and receivers are very cheap ( less then 10 cents a pair if you by them in Australia) with a very small Attiny (I think) arduino per unit (around 30 cents each) and a length on wire (34.6cm long as an aerial) for the cattle and 69.2cm for the repeaters. Note these calculations are based on the frequency used i.e. 433Mhz.
As I had to install lots of the repeaters I contacted an organisation in China (sorry they no longer exist) and they created a tiny waterproof and rugged capsule that contained everything, while also improving on the design (range wise while reducing power) at a cost of $220 for 100 units not including batterys. I bought one lot as a test and now between myself and my neighbours we bought another 2000 units for only $2750.
In my case this was paid for in less then three months when during calving season I knew exactly were they were calving and was on site to assist. The first time I used it we saved a mother who was having a real issue.
To end this long message I am not an expert but I had an idea and hired people who were and the repeater approach certainly works over long distances and large areas (42 square kilometres).
Following on from the comments above, I'm not sure where you are located but spectrum around the 400mhz range is licensed in many countries so it would be worth checking exactly what you can use.
If this is your target then this is UHF rather than VHF so if you search for 'Raspberry PI UHF shield' or 'Raspberry PI UHF module' you will find some examples of cheap hardware you can add to your raspberry pi to support communication over these frequencies. Most of the results should include some software examples also.
There are also articles on using the pins on the PI to transmit directly by modulating the voltage them - this is almost certainly going to interfere with other communications so I doubt it would meet your needs.
Hello wonderful community!
I'm currently writing a small game in my spare time. It takes place in a large galaxy, where the player has control of some number of Stars. On these stars you can construct Buildings, each of which has some number (0..*) of inputs, and produce some number of outputs. These buildings have a maximum capacity/throughput, and scaling down it's inputs scales down it's outputs by an equal amount. I'd like to find a budgeting algorithm that optimizes (or approximates) the throughput of all the buildings. It seems like some kind of max-flow problem, but none of the flow optimization algorithms I've read have differing types of inputs or dependent outputs.
The toy "tech tree" I've been playing with is:
Solar plant - None => 2 energy output.
Extractor - 1 energy => 1 ore output
Refinery - 1 energy, 1 ore => 1 metal
Shipyard - 1 metal, 2 energy => 1 ship
I'm willing to accept sub-optimal algorithms, and I'm willing to make the guarantee that the inputs/outputs have no cycles (they form a DAG from building to building). The idea is to allow reasonable throughput and tech tree complexity, without player intervention, because on the scale of hundreds or thousands of stars, allowing the player to manually define the budgeting strategy isn't fun and gives players who no-life it a distinct advantage.
My current strategy is to build up a DAG, and give the resources a total ordering (Ships are better than Metal is better than Ore is better than energy), then, looping through each of the resources, find the most "descendant" building which produces that resource, allow it to greedily grab from it's inputs recursively (a shipyard would take 2 energy, and 1 metal, and then the refinery would grab 1 energy and 1 ore, etc), then find any "liars" in the graph (the solar plant is providing 4 energy, when it's maximum is 2), scale down their production and propagate the changes forward. Once everything is resolved for the DAG, remove the terminal element (shipyard) from the graph and subtract the "current thruoghput" of each edge from the maximum throughput of the building, and then repeat the process for the next type of resource. I thought I'd ask people far more intelligent than me if there's a better way. :)
In an online manager game (like Hattrick), I want to simulate matches between two teams.
A team consists of 11 players. Every player has a strength value between 1 and 100. I take these strength values of the defensive players for each team and calculate the average. That's the defensive quality of a team. Then I take the strengths of the offensive players and I get the offensive quality.
For each attack, I do the following:
$offFactor = ($attackerTeam_offensive-$defenderTeam_defensive)/max($attackerTeam_offensive, $defenderTeam_defensive);
$defFactor = ($defenderTeam_defensive-$attackerTeam_offensive)/max($defenderTeam_defensive, $attackerTeam_offensive);
At the moment, I don't know why I divide it by the higher one of both values. But this formula should give you a factor for the quality of offense and defense which is needed later.
Then I have nested conditional statements for each event which could happen. E.g.: Does the attacking team get a scoring chance?
if ((mt_rand((-10+$offAdditionalFactor-$defAdditionalFactor), 10)/10)+$offFactor >= 0)
{ ... // the attack succeeds
These additional factors could be tactical values for example.
Do you think this is a good way of calculating a game? My users say that they aren't satisfied with the quality of the simulations. How can I improve them? Do you have different approaches which could give better results? Or do you think that my approach is good and I only need to adjust the values in the conditional statements and experiment a bit?
I hope you can help me. Thanks in advance!
Here is a way I would do it.
Offensive/Defensive Quality
First lets work out the average strength of the entire team:
Team.Strength = SUM(Players.Strength) / 11
Now we want to split out side in two, and work out the average for our defensive players, and our offensive players.]
Defense.Strength = SUM(Defensive_Players.Strength)/Defensive_Players.Count
Offense.Strength = SUM(Offense_Players.Strength)/Offense_Players.Count
Now, we have three values. The first, out Team average, is going to be used to calculate our odds of winning. The other two, are going to calculate our odds of defending and our odds of scoring.
A team with a high offensive average is going to have more chances, a team with a high defense is going to have more chance at saving.
Now if we have to teams, lets call them A and B.
Team A, have an average of 80, An offensive score of 85 and a defensive score of 60.
Team B, have an average of 70, An offensive score of 50 and a defensive score of 80.
Now, based on the average. Team A, should have a better chance at winning. But by how much?
Scoring and Saving
Lets work out how many times goals Team A should score:
A.Goals = (A.Offensive / B.Defensive) + RAND()
= (85/80) + 0.8;
= 1.666
I have assumed the random value adds anything between -1 and +1, although you can adjust this.
As we can see, the formula indicates team A should score 1.6 goals. we can either round this up/down. Or give team A 1, and calculate if the other one is allowed (random chance).
Now for Team B
B.Goals = (B.Offensive / A.Defensive) + RAND()
= (50/60) + 0.2;
= 1.03
So we have A scoring 1 and B scoring 1. But remember, we want to weight this in A's favour, because, overall, they are the better team.
So what is the chance A will win?
Chance A Will Win = (A.Average / B.Average)
= 80 / 70
= 1.14
So we can see the odds are 14% (.14) in favor of A winning the match. We can use this value to see if there is any change in the final score:
if Rand() <= 0.14 then Final Score = A 2 - 1 B Otherwise A 1 - 1 B
If our random number was 0.8, then the match is a draw.
Rounding Up and Further Thoughts
You will definitely want to play around with the values. Remember, game mechanics are very hard to get right. Talk to your players, ask them why they are dissatisfied. Are there teams always losing? Are the simulations always stagnant? etc.
The above outline is deeply affected by the randomness of the selection. You will want to normalise it so the chances of a team scoring an extra 5 goals is very very rare. But a little randomness is a great way to add some variety to the game.
There are ways to edit this method as well. For example instead of the number of goals, you could use the Goal figure as the number of scoring chances, and then have another function that worked out the number of goals based on other factors (i.e. choose a random striker, and use that players individual stats, and the goalies, to work out if there is a goal)
I hope this helps.
The most basic tactical decision in football is picking formation, which is a set of three numbers which assigns the 10 outfield players to defence, midfield and attack, respectively, e.g. 4/4/2.
If you use average player strength, you don't merely lose that tactic, you have it going backwards: the strongest defence is one with a single very good player, giving him any help will make it more likely the other team score. If you have one player with a rating of 10, the average is 10. Add another with rating 8, and the average drops (to 9). But assigning more people to defence should make it stronger, not weaker.
So first thing, you want to make everything be based on the total, not the average. The ratio between the totals is a good scale-independent way of determining which teams is stronger and by how much. Ratios tend to be better than differences, because they work in a predictable way with teams of any range of strengths. You can set up a combat results table that says how many goals are scored (per game, per half, per move, or whatever).
The next tactical choice is whether it is better to have one exceptional player, or several good ones. You can make that matter that by setting up scenarios that represent things that happen in game, e.g. a 1 on 1, a corner, or a long ball. The players involved in a scenario are first randomly chosen, then the result of the scenario is rolled for. One result can be that another scenario starts (midfield pass leads to cross leads to header chance).
The final step, which would bring you pretty much up to the level of actual football manager games, is to give players more than one type of strength rating, e.g., heading, passing, shooting, and so on. Then you use the strength rating appropriate to the scenario they are in.
The division in your example is probably a bad idea, because it changes the scale of the output variable depending on which side is better. Generally when comparing two quantities you either want interval data (subtract one from the other) or ratio data (divide one by the other) but not both.
A better approach in this case would be to simply divide the offensive score by the defensive score. If both are equal, the result will be 1. If the attacker is better than the defender, it will be greater than 1, and if the defender is stronger, it will be less than one. These are easy numbers to work with.
Also, instead of averaging the whole team, average parts of the team depending on the formations or tactics used. This will allow teams to choose to play offensively or defensively and see the pros and cons of this.
And write yourself some better random number generation functions. One that returns floating point values between -1 and 1 and one that works from 0 to 1, for starters. Use these in your calculations and you can avoid all those confusing 10s everywhere!
You might also want to ask the users what about the simulation they don't like. It's possible that, rather than seeing the final outcome of the game, they want to know how many times their team had an opportunity to attack but the defense regained control. So instead of
"Your team wins 2-1"
They want to see match highlights:
"Your team wins 2-1:
- scored at minute 15,
- other team took control and went for tried for a goal at minute 30,
but the shoot was intercepted,
- we took control again and $PLAYER1 scored a beautiful goal!
... etc
You can use something like what Jamie suggests for a starting point, choose the times at random, and maybe pick who scored the goal based on a weighted sampling of the offensive players (i.e. a player with a higher score gets a higher chance of being the one who scored). You can have fun and add random low-probability events like a red card on a player, someone injuring themselves, streakers across the field...
The average should be the number of players... using the max means if you have 3 player teams:
[4 4 4]
[7 4 1]
The second one would be considered weaker. Is that what you want? I think you would rather do something like:
(Total Scores / Total Players) + (Max Score / Total Players), so in the above example it would make the second team slightly better.
I guess it depends on how you feel the teams should be balanced.