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A LETTER FROM
Rob
The Curry Paradox
On February 27, 2016, Steph Curry hit an
iconic 38-foot game-winning three-pointer, giving the Golden State Warriors a 121–118 overtime victory
against the Kevin Durant–led Oklahoma City Thunder. Mike
Breen, brilliant as always, had the call:
“They have a timeout, decide not to use it. Curry, way
downtown… BANG! BANGGG! Ohhh, what a shot from
Curry!”
Curry's 38-footer over Oklahoma City, February 27, 2016.
During the 2015–16 season, Steph shot an absurd 44% from
beyond 30 feet on 32 attempts. For context, the other 3-point
leaders that year were Klay Thompson, Damian Lillard, and
James Harden. All future Hall of Famers. Between the three of
them, they attempted only 18 shots from beyond 30 feet, and
made only 3.
Because shooting from beyond 30 feet just doesn't make
sense…unless you're Steph Curry.
| Player |
3-Point Shots |
+30 ft |
| Steph Curry |
402 / 866 (45.2%) |
14 / 32 (44%) |
| Klay Thompson |
276 / 646 (42.7%) |
1 / 5 (20%) |
| Damian Lillard |
229 / 602 (37.7%) |
2 / 11 (18%) |
| James Harden |
236 / 657 (36.0%) |
0 / 2 (0%) |
Let's take a look at
one more game-winner, this time from 2019. We join this game with only 3.1 seconds
left on the clock. The Hornets are down 114–112 against the
Toronto Raptors. Jeremy Lamb receives the inbounds pass, and
immediately loses control of the ball. He has to run back
beyond half court to chase it down. By the time he grabs it,
he has less than a second to spin 180° and throw up a heave.
Miraculously, the ball hits off the backboard and drops in to
the sound of the buzzer against a silenced crowd.
By any measure, Lamb's shot was more difficult. (a) He was
further away, (b) he had less time to set up, and (c) he was
practically spinning as he shot it. And within the game, it
was a higher-stakes shot — the Hornets were down two, not tied
like Golden State. Yet…it's the less impressive shot.
And I'd bet almost all fans would agree, even if they can't
tell you why.
So here's the puzzle. If we grade shots on probability,
Lamb's clears easily. His shot was less likely to go in, so
when it did, something more improbable happened. So his shot
should be more impressive, right? But it isn't.
The Curry Paradox:
Curry's iconic 38-foot game-winner is more impressive than
Lamb's wilder half-court heave.
The less surprising the make, the more impressive it is.
When a shot goes in, there are two questions we can ask.
How unlikely was that? And
what does it tell me about the shooter?
Lamb's heave was literally a long shot, essentially a lottery
ticket. An elite shooter, a benchwarmer, or just a guy off
the street all make that shot at roughly the same near-zero
rate. The make is rare, but it's rare in about the same way
for everybody. So when it goes in, it doesn't tell you much
about Lamb you didn't already know. You don't walk away with
a stronger belief about him. You walk away shocked at what
just happened.
Curry's game-winner is different because shooting 35-footers
at a 40% clip is something only Curry produces. The league
hits maybe one in twenty shots from that spot; Curry hits closer to
one in two. When his shot went in, we're not watching a coin
land on its edge, we're watching a master at work. It was a
make consistent with a shooter who's rewritten basketball
geometry, and inconsistent with almost anyone else.
The make tells you something only when one explanation
predicts it far better than another.
Information theory gives us a nice framing for this: an
observation tells you something about a hypothesis only when
it's more likely under one hypothesis than another.
Lamb's heave is essentially equally likely under
“Lamb” and “anyone else,” so it
doesn't discriminate between them. Curry's shot is far more
likely under “Curry” than under “typical
NBA shooter.”
In other words, the rarity alone isn't information. It's not
how rare is this event in the world, but
how much rarer is it under one explanation than another.
Lamb's shot was surprising. Curry's shot was
meaningful.
The Curry Paradox arises when, in information theory lingo,
surprisal and weight of evidence are
conflated. Our gut says “impressive” should
track surprisal — the rarer the event, the more impressive.
But I think what we actually respond to when we say a shot
is “impressive” is weight of evidence. We're
impressed by what the shot proves about the player, not by
how unlikely the event was in a vacuum.
Steph hitting that shot wasn't an event in a vacuum. It's
his signature.
— Rob
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