The Jeopardy thread [was James Holzhauer][contains spoilers]

But this guy doesn’t bet on casino games. He’s a sports gambler, betting on football, baseball, basketball and so forth. I don’t know enough about this to say if that’s a workable business.

The problem isn’t that he’s too good, the problem is that his opponents aren’t good enough. It’s not Mike Trout’s fault that he’s the best player in baseball. Imagine if there were two other players of his skill level playing against him, it would be an insanely entertaining game.

In principle, it can be, if there are enough irrational betters around.

Jimmy the Greek was a professional sports gambler as well as tv personality.

And therein lies the problem with “marrying a professional gambler.”

You can have an office building full of engineers, lawyers, doctors, bricklayers, whatever, and they can all be making money. But you have an office full of professional sports gamblers, and you’ll have (say) 10% making money and 90% losing all their money. Because sports wagers don’t come from a vacuum, they come from other sports gamblers. And it is a zero-sum field.

While acknowledging that there can be successful professional gamblers, if I met a random person who claimed to be one, I wouldn’t trust that they actually were. Someone is losing the money the successful ones are earning.

From the interview with him I linked above, it sounds like he makes his money by making bets where the bookies aren’t setting the odds correctly, not by going against suckers.

(bolding mine)

The sports gamblers who make money aren’t going out and betting seven games a day. They are choosing the relatively occasional game where the odds are off. Often this isn’t because the bookies set the odds wrong. It’s because the bookies need to move the odds because there is too much action in one direction. The bookies don’t give a shit about being “right” they just want the action to match on either side. For example, they got killed when Tiger won the Masters because all of the emotional bets on him shifted the betting too much.

A skilled bookie would have taken the emotional bets into account, and given Tiger better odds, to encourage more bets against him.

And whenever a professional gambler is succeeding, it’s because there’s some sucker somewhere. Who precisely it is might vary. The sucker might or might not be another professional.

EDIT: That said, yes, someone describing themselves as a “professional gambler” or a “successful gambler” should be taken with a very large grain of salt.

I don’t really gamble, so forgive my ignorance, but isn’t betting supposed to drive the line, anyway for the reasons you state? I thought typically there was a starting line, the bets would come in, and adjustments would be made to even out the betting on both sides, so the bookie always comes out ahead. Is that typically not how it works?

In sports betting, yes, the spread movement (or the line) is changed by how much has been bet for one team or player over the other. Changing the spread will push more action the other way, etc. This way the house has ends up as close to even bets on each side of the game. They then collect the “vig” or “juice” as their share of the winnings for taking the bets.

The house is in the business to collect the juice, not to pick a side and win against all other takers.

It is. And the Tiger thing was so overwhelming that the books lost big. They couldn’t get enough action the other way. Too many people who never bet golf bet on him. Stuff like that happens occasionally. No biggie, they can absorb the rare loss like that.

I always take all those “Bookies lose big” with a grain of salt. They’re the ones putting out that information so then people think “Hey, maybe I can beat the system.”

This is a misconception. Bookmakers regularly lose on individual events. They take the long term view, and will not stray too far from what their numbers guys believe are the true odds, regardless of how lopsided the betting is. For example, in a prominent horse race the bookmakers will have a large liability on the favourite, and a profit on the field. Each race has a good chance of being a big loss for the bookmaker, but it is the repetition over thousands of races that ensures their profit.

I agree. It’s not like we see the balance sheets.

I was kinda curious about this too (since I’ll always remember how Watson clearly wasn’t programmed to properly take the categories in account given the infamous U.S. Cities/Toronto answer). Looking it up on J-Archive (putting in spoiler tags to save space):

Game 1:
Jeopardy
Literary Character APB: Watson got 4/5 including DD, Brad rang in first on the other one
Beatles People: Watson got 4/5, Ken rang in first on the last
Olympic Oddities: Watson 3/5, Ken 1/5, the last was a triple stumper on which Watson and Ken both gave the same wrong answer
Name the Decade: Interestingly, Ken and Brad cleaned up on this one, with Watson only ringing in once (and getting it wrong).
Final Frontiers: Watson got 2/5, and gave a wrong answer on another.
Alternate Meanings: Watson got 2/5, and gave a wrong answer on another.

Double Jeopardy
Etude, Brute: Watson 5/5
Hedgehog-Podge: Watson 5/5
Don’t Worry About It: Watson 4/5
The Art of the Steal: Watson 2/5 (inc. DD), Ken 1, two triple stumpers (one all wrong, one no ring-ins)
Cambridge: Watson 4/5 (inc. DD), Brad 1
“Church” & “State”: Watson 3/5, Brad 1, Ken 1

Final Jeopardy
U.S. Cities (“What is Toronto???”)

Game 2:
Jeopardy
EU, the European Union: Watson 3/5, Ken 1, triple stumper (Watson/Brad wrong)
Actors Who Direct: Brad 3/5, Ken 2/5
Dialing for Dialects: Watson 4/5
Breaking News: Watson 3/5, Ken 1 (DD), Brad 1
One Buck or Less: Ken 4/5, Brad 1
Also On Your Computer Keyboard: Brad 3/5, Ken 1/5, triple stumper (Watson/Ken wrong)

Double Jeopardy
Nonfiction: Watson 3/5, also got the DD wrong, Brad 1
Legal "E"s: Watson 4/5 (inc. DD), Ken 1
What to Wear?: Watson 2/5, Ken 2/5, Brad 1
U.S. Geographic Nicknames: Watson 3/5, Brad 1, Ken 1
Magical Mouse-tery Tour: Watson 3/5, Ken 2
Familar Sayings: Watson 3/5, Ken 1, Brad 1

Final Jeopardy
19th Century Novelists (all got it right)

So yeah, there weren’t any out-and-out ‘clever’ categories like Before & After or such, but it does seem like there were a couple it had trouble with. Watson didn’t seem to like “name the decade”, probably because a lot of the prompts didn’t include any specific question (instead just saying something like “Disneyland opens”). Same thing for “actors who direct” as every clue was just movie titles with no prompt. Interestingly it didn’t like “one buck or less” either even though it had relatively normal clues, maybe just not enough factoids in Watson’s database about prices? Didn’t like “also on your keyboard” either.

Interestingly it didn’t seem to have trouble with the ones with the quotes in the titles, likely because the actual clues were still normal enough even without needing the “E” or “church”/“state” to narrow it down.

The Watson games were certainly rigged in it’s favor (especially since it came down really to buzzer speed), but I always just saw it as more of a proof of concept then anything. I mean, you try asking Siri “You’re just a little stiff! You don’t have this painful mosquito-borne joint illness with a Swahili name”

I watched him again last night, what’s with his oddly specific bets? Last night he bet something like $9,013. It will be interesting to see the game catch up to him.

He has stated that the weird bets are often important dates to him, but that he has rapidly run out of family birthdays, anniversaries, and the like.

Two articles, CNN and NPR, on his streak:

Spoilers for 4/23 episode:

He’s now broken 1 million in half the time Jennings did