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The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

grantland.com

1–10 of 31 posts

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#2
The "ghost" players in these animated replays that show where the system thinks a player should have been are fascinating to see. I wonder how automatic it is - if games could be analyzed like that without much expert input, this would be a really cool thing to have for recreational teams who want to get better but can't afford expert coaching. I'm thinking my late-night adult league hockey team would probably benefit from some replays like this.

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#3
post #2

The "ghost" players in these animated replays that show where the system thinks a player should have been are fascinating to see. I wonder how automatic it is - if games could be analyzed like that without much expert input, this would be a really cool thing to have for recreational teams who want to get better but can't afford expert coaching. I'm thinking my late-night adult league hockey team would probably benefi…

It would be interesting - though it will be some time before the price comes down. The cameras to do the tracking cost $100k/year at the moment.

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#4
The camera presumably is overhead. From that perspective, what could be a useful feature for person tracking? I am assuming it wont be that easy to pickup just numbers of their jerseys. Faces are also not easy to get from that angle. Or do they have multiple cameras in place?

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#5
post #2

The "ghost" players in these animated replays that show where the system thinks a player should have been are fascinating to see. I wonder how automatic it is - if games could be analyzed like that without much expert input, this would be a really cool thing to have for recreational teams who want to get better but can't afford expert coaching. I'm thinking my late-night adult league hockey team would probably benefi…

I'd be pretty curious about that too. I actually tried doing something semi-similar before. My goal was to simulate a basketball game by having every player take an action based on "expected points per possession". So if you are covered tightly but a shooter is open, your expected points would be high for passing but low for shooting. This would then be done recursively for every decision, continuously looking ahead until the shot clock expires (so maybe the best move would be to pass it into the post, draw a double team, and then kick it out for an open shot).

The obvious problem was that there are a ton of free parameters involved and tons of branching. Every little action creates a new branch of possibilities with its own set of probability distributions. So even if (as they describe in the article) helping out more often decreases the likelihood of the current ball handler making a shot, how does that propagate through the rest of the possession?

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#6
post #2

The "ghost" players in these animated replays that show where the system thinks a player should have been are fascinating to see. I wonder how automatic it is - if games could be analyzed like that without much expert input, this would be a really cool thing to have for recreational teams who want to get better but can't afford expert coaching. I'm thinking my late-night adult league hockey team would probably benefi…

Unfortunately the cameras are pricey enough that only 15 of 30 NBA teams have purchased them, not to mention the half decade of work it took the Raptors to build the code to actually generate the visualizations. Maybe someday it will be commercially available and affordable, but that day seems a long way off to me.

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#7
post #4

The camera presumably is overhead. From that perspective, what could be a useful feature for person tracking? I am assuming it wont be that easy to pickup just numbers of their jerseys. Faces are also not easy to get from that angle. Or do they have multiple cameras in place?

I could be wrong, but I would guess that they're not mounted overhead for that reason. At least not directly overhead. Since the court is a known, fixed size, I think you'd be able to project the players' location from a normal camera view onto an overhead representation like they show in the article's videos.

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#8
Great article. As a huge NBA & NFL fan, It's intriguing to see the front offices of some of these teams begin to think outside of the box when it comes to player development. I think that's the most interesting opportunity here -- the practice of "watching film" is now innovative enough to not only help prepare for opponents, but also provide coaches a better macro view of what to work on with specific players in the short & long term. Especially in coaching behavior "off the ball". Thats always a game changer.

The ghost AI is pretty impressive as well. I was skeptical at first as to how authentic this type of "player AI" would be, considering the program makes assumptions based on historical numbers and any athlete/coach would certainly argue that its different in-game, however this says a ton:

> That's brutal, and it's not a coincidence that the only team that consistently mirrors the help defense of its ghosts is Miami, Rucker says. The Heat have three of the best wing defenders in the league in Shane Battier, LeBron James, and Dwyane Wade, and the latter two are among the NBA's most gifted pure athletes. James can mimic DeRozan's hyperactive ghost in a way no other player can, Rucker says. "LeBron basically messes up the system and the ghosts," Rucker says. "He does things that are just unsustainable for most players."

Not a huge Miami fan (Go BULLS!) but you can't deny their defensive effort.

Thanks for sharing!

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#9
post #3
post #2

The "ghost" players in these animated replays that show where the system thinks a player should have been are fascinating to see. I wonder how automatic it is - if games could be analyzed like that without much expert input, this would be a really cool thing to have for recreational teams who want to get better but can't afford expert coaching. I'm thinking my late-night adult league hockey team would probably benefi…

It would be interesting - though it will be some time before the price comes down. The cameras to do the tracking cost $100k/year at the moment.

$100k/year is certainly a lot :)

I can imagine facilities like hockey rinks buying the cameras and selling the service to the teams that play there, but not at that price. My impression of hockey rinks is that they're not terribly profitable. Most of the ones I've played in seem like borderline charities.

Re: The Toronto Raptors, SportVU cameras, and the NBA's analytical revolution

#10
post #4

The camera presumably is overhead. From that perspective, what could be a useful feature for person tracking? I am assuming it wont be that easy to pickup just numbers of their jerseys. Faces are also not easy to get from that angle. Or do they have multiple cameras in place?

probably use 2 - 3 camera to triangluate location

if you only have to idenitify 24 people, you could probably do that on height plus some other physical dimension

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