Rajiv Maheswaran: The math behind basketball's wildest moves
拉吉夫·馬赫斯沃倫: 籃球瘋狂動作背後的數學原理
Using advanced data analysis tools, Rajiv Maheswaran and Second Spectrum help make basketball teams smarter. Full bio
Double-click the English transcript below to play the video.
by the science of moving dots.
背後的科學非常著迷。
in our offices, as we shop and travel
甚至世界各地旅遊和購物。
and around the world.
if we could understand all this movement?
不是很棒嗎?
and insight in it.
意義和背後意涵的話。
非常容易的時代,
at capturing information about ourselves.
sensors or videos, or apps,
with incredibly fine detail.
where we have the best data about movement
獲取動作資訊的一個地方,
or football or the other football,
and our players to track their movements
安裝儀器,追蹤他們的動作 --
is turning our athletes into --
就是把運動員變成──
and like most raw data,
但就像大部分的原始數據一樣,
and not that interesting.
basketball coaches want to know.
籃球教練想知道的事。
because they'd have to watch every second
因為他們得看著每一秒鐘的比賽,
the game with the eye of a coach.
教練的角度觀看比賽,
shots and rebounds.
投籃、搶籃板等動作,
slightly more complicated.
and pick-and-rolls, and isolations.
Most casual players probably do.
打球的人大概都清楚。
the machine understands complex events
機器已經可以讀出複雜的動作,
with the eyes of a coach.
用教練的角度來看比賽。
something like a pick-and-roll,
某個動作,例如擋切,
it would be terrible.
一個演算法,大概會慘不忍睹。
in basketball between four players,
四個球員之間的舞蹈,
without the ball
guarding the guy with the ball,
and ta-da, it's a pick-and-roll.
——嗒啦——這就是擋拆。
of a terrible algorithm.
he's called the screener --
but he doesn't stop close enough,
and he does stop
it's probably not a pick-and-roll.
they could all be pick-and-rolls.
時機、距離和位置,
the distances, the locations,
we can go beyond our own ability
我們得以用超越自己的能力,
Well, it's by example.
"Good morning, machine.
and here are some things that are not.
也有些不是的例子。
features that enable it to separate.
可以進行區別的特徵。
to teach it the difference
「不妨用顏色或形狀來區分?」
use color or shape?"
類似這樣的特徵是什麼?
what are those things?
能暢行無阻的重要特徵?
the world of moving dots?
with relative and absolute location,
包含相對和絕對位置、
of moving dots, or as we like to call it,
或者用我們喜歡的稱呼方式:
in academic vernacular.
you have to make it sound hard --
必須讓它聽起來很難,
it's not that they want to know
他們想知道的
how it happened.
So here's a little insight.
這裡有一些發現。
the most important play.
and knowing how to defend it,
and losing most games.
has a great many variations
is really the thing that matters,
to be really, really good.
and two defensive players,
the pick-and-roll dance.
can either take, or he can reject.
can either go over or under.
從前繞開、或從後繞開。
or play up to touch, or play soft
隨球盯人或向後消極防守,
either switch or blitz
most of these things when I started
according to those arrows.
的方向移動就太棒了,
but it turns out movement is very messy.
但我們的動作往往非常雜亂。
these variations identified
a professional coach to believe in you.
才能取得專業教練的信任。
with the right spatiotemporal features
時空特徵困難重重,
辨識這些變化的能力。
to identify these variations.
almost every single contender
爭奪NBA冠軍的隊伍
on a machine that understands
安裝在可以讀懂籃球場上
that has changed strategies
我們的建議改變一些戰術,
very important games,
coaches who've been in the league
因為我們讓這些在聯盟裡
願意聽一台機器的建議。
advice from a machine.
it's much more than the pick-and-roll.
with simple things
much of what it does,
to be smarter than me,
can a machine know more than a coach?
機器有可能懂得比教練還多嗎?
to take good shots.
it's a good shot.
通常就是很差的投籃時機。
by defenders, that's generally a bad shot.
or how bad "bad" was quantitatively.
「好」有多好、「差」有多差。
using spatiotemporal features,
利用時空特徵條件,
What's the angle to the basket?
和籃框的角度是幾度?
What are their distances?
at how the player's moving
我們可以觀察球員如何移動
and we can build a model that predicts
would go in under these circumstances?
and turn it into two things:
and the quality of the shooter.
because what's TED without a bubble chart?
沒有泡泡圖還像TED嗎?
and the color is the position.
顏色代表他打的位置。
we have the shot probability.
bad at the bottom.
不擅長的在下方。
47 percent of their shots,
takes shots that an average NBA player
這個球員出手投籃的狀況,
is that there are lots of 47s out there.
有這麼多47%命中率的球員。
giving 100 million dollars to
簽下一個47%的球員,
how we look at players,
我們對球員的看法,
a couple of years ago, in the NBA finals.
有一場非常刺激的比賽。
there was 20 seconds left.
時間還剩20秒。
came up and he took a three to tie.
出手一顆三分球企圖追平比賽,
named Ray Allen.
將比賽帶入延長賽,
They won the championship.
games in basketball.
the shot probability for every player
在每一秒鐘投進的機率,
a rebound at every second
窺見這個時刻的全貌。
that we never could before.
I can't show you that video.
about 3 weeks ago.
我們每週例行的籃球比賽裡。
that led to the insights.
比賽全貌的追蹤數據。
This is Chinatown in Los Angeles,
在洛杉磯的中國城,
the Ray Allen moment
that's associated with it.
of the professional players, it's us,
不是那些職業球員。
announcer, it's me.
chance of happening in the NBA
賽場上的機率大約是9%,
and a great many other things.
和其他許多事的機率。
it took us to make that happen.
我們試了幾次才成功。
of every NBA game -- it's not that.
每一秒鐘的意涵。
a professional team to track movement.
才能追蹤人的動作,
player to get insights about movement.
才需要這些動作背後的意涵。
sports because we're moving everywhere.
因為我們隨時都不斷地在各地移動。
pick-and-rolls,
the moment and let me know
any second now.
our buildings, better plan our cities.
利用建築物、做更好的都市規劃。
of the science of moving dots,
we will move forward.
並真正向未來移動。
ABOUT THE SPEAKER
Rajiv Maheswaran - ResearcherUsing advanced data analysis tools, Rajiv Maheswaran and Second Spectrum help make basketball teams smarter.
Why you should listen
Sports fans can get obsessed with stats about player performance and game-day physics. But basketball, a fluid and fast-moving game, has been tough to understand through numbers. Rajiv Maheswaran is working to change that, by offering pro basketball teams insight into game data to make better decisions. Maheswaran is the CEO and co-founder of Second Spectrum, a startup transforming sports through technology. He is also a Research Assistant Professor at the University of Southern California's Computer Science Department and a Project Leader at the Information Sciences Institute at the USC Viterbi School of Engineering, where he co-directs the Computational Behavior Group.
His research spans various aspects of multi-agent systems and distributed artificial intelligence using decision-theoretic and game-theoretic frameworks and solutions. His current interests focus on data analytics, visualization and real-time interaction to understand behavior in spatiotemporal domains. Like, say, the spatiotemporal domain around a basketball hoop.
Rajiv Maheswaran | Speaker | TED.com