Premium data subscriptions deferred until January

Due to a confluence of personal priorities, migration of some 2018-19 data files to premium subscription status will be delayed until January. Subscription details will be announced sometime in the second week of January.

Until then, continue to enjoy the 2018-19 data for free. Happy Holidays!

VMI Ranges Beginning to Tell a Story

As many of you have also been doing, I have been watching the NBA performances aligned with the VMI formulas. Of course, we still have many games to go and a number of data points to gather before we know the truth, but there are some signs that are taking shape.

As of today, another marker followed suit, as was expected. That is; if one looks closely at the three point shooting in the NBA, the percentages made within all the ranges of the VMI have now dropped below the percentages made in the zero to 5.99 VMI Ranges shooting percentages. That, of course, was expected to occur and certainly by the All Star Break.

Based on the understanding that the heavier air would hold the ball back by more than an inch in the minus VMI ranges above 6.00, which track the teams' exposure throughout their individual schedules, all those accuracy percentages in the ranges above 6.00 have now dropped below the accuracy percentage achieved where the shooting is minimally affected by the air.

At this point, less than 1/3 of the season is behind us, but whether plus VMI, or minus VMI, all the ranges show less accurate shooting the further from zero the VMI identifies the teams' need for adjustment. It is doubtful that the 3-point shooting in the higher ranges will exceed the minimally affected production for the remainder of the season.

Lebron's Comments a Season Ago Come Back Around

Last year Lebron James made a statement about Denver Nuggets poor shooting. After last Tuesday's game in Denver, Lebron may have a new view of how difficult it is to adjust to and from high altitude 3-point shooting.

In season's past, Lebron has had a good game in Denver and returned later for a bad one. Tuesday in his most recent trip, he had arguably the worst game in his career going 0 for 4 from outside and helping his team to an embarrassing loss to the Nuggets.

The Lakers as a team shot 5 for 35 on three pointers as they sported a +21.88 VMI, meaning their shots would be several inches long and each player must adjust. No Laker hit more than 1 3-pointer in their loss to the Nuggets whose VMI was 5 something, meaning they would probably be less than an inch off from their usual shooting distance.

The truth is, this does not mean it will happen every time a team transitions to Denver or Utah or Phoenix, Oklahoma City, Atlanta and a couple other higher altitude venues. We don't know the percentages of accurate determination of either wins & losses, or 3-point shooting, or defensive rebounding yet. It may take a full season, or more to determine what the percentages of accuracy the VMI can be trusted for, but it now appears that day is going to arrive.

When I first began to observe the three-point shooting differential was in 2001 to 2005, or about the time Josh Kroenke was playing for the University of Missouri Tigers Basketball Team. The Tigers transitioned from Missouri to the University of Colorado for a game which I was totally convinced would be a "Slam Dunk" win for Colorado due to outside shooting.

The absolute opposite happened. The Tigers adjusted very nicely in that game and sunk 3-pointer after 3-pointer in a blow out win against Colorado in Boulder at 5,500 feet in elevation. In particular, I noticed that the success seemed to come when they stepped back a few feet from the three point arc to shoot. Those longer shots happened to be the perfect way to combat the altitude for that game, but it doesn't always work that way. Kobe Bryant did the same thing against the Denver Nuggets on many occasions, but he too, struggled to make it work all the time.

So, all we can say at this point is that the players need to adjust. Some will adjust better than others and some teams will adjust better, as well. However, there is a percentage that will reveal itself some time this year. It will be repeated over the next couple years to provide us with an answer as to how often do individuals and teams make the adjustment flawlessly, and how often can we count on disaster for the teams trying to overcome the altitude transitions.

To view and/or make comments, visit BasketballVMI Blog

VMI and ADI data now included in NBA master file

VMI and ADI data for all 2018-19 NBA games is now included in the RotoGuru/DHD NBA master file. These two data elements have now been appended to the end of each player data line.

The NBA master file is still available for free, but will eventually convert to a premium basis, available only by subscription. Subscription details will be announced later in November.

Once the file transitions to a premium basis, ADI and VMI values for the current game day will be restricted to those who are also members at basketballVMI.com. (Note that all baseballVMI.com members will automatically be grandfathered with basketballVMI membership for this season.) Historical ADI and VMI data will be unrestricted (i.e., available to all).

For more information on the basketball VMI index, please visit BasketballVMI.com.

(Note: ADI and VMI data are not available for prior seasons.)

Effects of altitude on a basketball three-point shot

As stated earlier, most people are aware of the differences in flight distance of a baseball, football, or golf ball between sea level and the altitude of Denver, Colorado, which represents the extreme altitude for many professional sports. However, few have given much thought to the three-point shot in basketball as it relates to all the teams in the NBA and College basketball.

Recently, the Golden State Warriors visited Denver, Colorado for a matchup of the best 3 point shooting team in recent history vs the Nuggets who have long been the worst 3 point shooting team in NBA history. Neither team is used to playing NBA basketball in Denver’s higher altitude. It showed.

The Warriors made 7 of 29 shots for a 24.1 percentage when they normally are almost twice that production clip. The Nuggets, who are playing better to begin this season, made 6 of 32 shots for a paltry 18.8 percentage. Both teams had done some shooting at Denver and Utah, but it did not solve all the issues that come up during game time action.

The ADI that we present at www.basketballvmi.com gauges primarily the barometric pressure and the VMI that we present not only on our website, but will also provide on this site as well, gauges the conditions that are normal for the two teams in any NBA match-up. The Warriors were a plus 14.84 for that game, meaning they were used to shooting about 3-1/2 inches longer to hit their 3-pointers. Not all the players adjusted well, and this is the purpose of the VMI for Basketball. It should tell you something about the additional opportunities for offensive and defensive rebounds, as well as when a team is “out of their element.”

"Actual Barometric Pressure" stated in "Inches of Mercury"

One of the most significant issues for basketball people to understand is actual air pressure. The hidden truth about pressure is inadvertently hidden from the public by the media, because meteorologists speak of barometric pressure from a "sea level" measurement. Meteorologists must present a clear picture of air pressure highs and lows so that they can keep a watch on the small daily pressure changes within "all" altitudes across the nation and around the world. Therefore, they have adjusted the standard air pressure at all locations to "sea level", but this does not represent the "actual pressure" for the elevation.

In order to adjust the standard sea level pressure measurement of 29.92 inches of mercury to the actual pressure at differing altitudes, one must subtract approximately 1 inch of mercury for every 1,000 feet of altitude. Therefore Phoenix, AZ would normally read approximately 28.92 actual barometric pressure; Las Vegas, NV at 2500 feet in elevation would normally read about 27.00 inches of mercury; Lubbock, TX air pressure would be represented at about 26.50 inches of mercury; and Denver, CO normal air pressure is actually measured at 25.42 inches of mercury.

The basketball is larger than that used in most sports projectiles and is full of air, so is light in weight. On a three-point shot and without spin, it does not "knuckle" in flight because it does not have any large smooth surfaces. It probably does not lift due to backward spin either, because there are no exterior protrusions (such as seams) and the lack of speed would also not allow it to lift in flight.

The thrust at the release point is the fastest speed of the shot and, of course, due to gravity, slows as it reaches the top of the arc. The speed then increases from that point to the basketball rim. The air resistance is applied from the beginning of the shot all the way to the rim, therefore the difference in amount of air resistance is the reason the distance of the flight changes from climate to climate. See our discussion about "Air Weight" for a better understanding of the difference between altitudinal air densities.

Milibars

An interesting side note: When it comes to media discussions of air pressure in weather related events, such as hurricanes, Meteorologists convert the conversation from "inches of mercury" to pressure in "milibars." Why? Well, it keeps the non-professionals guessing as "Terminology" is the great separation between layman and professional. It may be easier to drop the decimals off "inches of mercury" and use milibars instead, but essentially they express the same air pressure.

Sea level "inches of mercury" actual pressure is stated as 29.92 hg (inches of mercury) which can also be stated as 1013 Milibars, as they are the same. Another expression for the same air pressure is 14.7 psi (pounds per square inch).

So at sea level actual pressure is 29.92 hg, or 1013 pa (milibars in pascal), or 14.7 psi. However, actual pressure at Denver, CO at 5,200 feet elevation is 25.10 hg, or 850 pa, or 12.33 psi.

It is this "850 pa" that I want to point out at Denver, Colorado which is standard air pressure for that altitude. Pressure inside a hurricane periodically hits 850 or so milibars, because the centrifugal force applied by wind at the exterior edge pulls the molecules apart with a huge force causing the air pressure to drop to the same as in Denver, but the outside air pressure is 1013 milibars. This pressure differential is what causes extreme damage and extremely high winds. Does that give you pause as it relates to a basketball flying through air in Denver as opposed to air at sea level? It does for me.

Game stats are up

Reporting is now up for regular season NBA player stats.

• Daily Fantasy Point Recaps are available for FanDuel, Draftkings, and Yahoo DFS. You can choose to view players sorted by position (default), or in boxscore order. In addition to the standard html output, SCSV (semi-colon delimited values) formatting is available as an option.
• The NBA master file is also available. For details on the format, see rotoguru1.com/hoop/nba-dhd-2019-notes.txt.

As in past seasons, the master file and the SCSV version of the daily recaps will eventually be available only via premium subscription. But for at least the next four weeks, they will be provided for free.

Getting ready...

I'm in the process of resetting all of the various DHD/RotoGuru Hoops reporting for the 2018-19 NBA season

As of today, I have tentative working versions of the following:

• Sortable Stats, with DFS salary data for FanDuel, DraftKings, and Yahoo DFS. Note that I am only capturing salary data for the "Classic" format with the full daily slate of games. I will not be capturing salary data for single-game formats. Note that if you choose the trailing 7, 15, or 30 day periods, preseason games will be included. If you select "full season", preseason games will be excluded. (So if you want to see any data prior to the start of the season, don't select "full season".)
  
• Game-by-game player histories for the current season. From this page, you can also drill back to prior year histories.

As in the past several years, I will be producing the premium NBA master data file. This will hopefully be available by Wednesday, October 17. The file will be provided for free for at least the first four weeks of the NBA season. Subscription details will be announced around the beginning of November. (Remember that a separate subscription is required for each NBA season.)

Daily point recaps and the Stat Summarizer will be available by sometime on Wednesday as well. Stay tuned for further announcements as these come online.

As always, if you notice anything that looks to be incorrect, please send an email to davehall@rotoguru2.com.

COMING SOON—WWW.BASKETBALLVMI.COM

Special announcement from www.BasketballVMI.com:

As many of you already know from having read "Baseball Unraveled" by Clifton Neeley--Basketball is also affected by air resistance.

Since the NBA season is right around the corner, VMI is introducing "BasketballVMI." Within a few days of the opening of the regular NBA Season in 2018, we should be able to present the schedule ahead of game time and track the ADI and VMI for all the teams.

What will be the "Real World" focus for Basketball as it relates to NBA teams?

For Basketball, the issue is not the trajectory, but the distance of flight of the three point shot. Most everyone knows that golf balls, footballs, and other projectiles fly further in higher altitude locations than at sea level venues. Taking this concept a step further, we know that every venue between high altitudes and sea level, such as Oklahoma, Arizona, Atlanta, Texas, Minnesota and others are affected by air resistance differently. Can this be affecting 3 point shooting around the league when teams transition between those venues? How does good or bad 3 point shooting affect the other aspects of the game, such as rebounding and put-backs?

For the three point shot, the sensitive touch of the shooter is highly affected if what the shooter sees and muscle memory remembers as the amount of wrist and finger snap changes due to air resistance either holding the ball back a few inches, or freeing the ball to fly further than he/she is used to.

Since most, if not all, NBA and College basketball is played indoors, then temperature and humidity are not significant factors under normal playing conditions. However, "Actual" barometric pressure is a significant factor verified by Dr. Robert Adair, Professor Emeritus in Physics and author of The Physics of Baseball, Yale University.

We at Air Resistance Technologies will present for you a VMI based on a formula by Clifton Neeley which identifies when a team of players will be used to a shot flying 1 to 6 inches further or shorter than they are used to feeling and therefore affecting the overall shooting percentages, rebounding opportunities and put-back opportunities.

Stay tuned...