A version of this story originally appeared on Phil Birnbaum’s blog Sabermetric Research.
Is poker a game of pure luck, or is there skill involved, too?
One way to test, as Stephen Dubner suggested, is to check if it's possible to lose on purpose. If it is, then there must be skill involved, because the player has some control of the outcome. And, of course, it is possible to lose at poker at will, if you want to ... so it's reasonable to argue that poker is a game of skill.
On the other hand, you can't lose the lottery on purpose, no matter how hard you try. So, the lottery is just a game of luck.
But ... there are exceptions to the "lose on purpose" rule.
An easy one is tic-tac-toe. It's easy to lose on purpose—just go second, and take a side square when it's your turn. The first player, assuming he plays his best, is certain to beat you. On the other hand, you can't win on purpose. If both competitors play optimally, the result will always be a draw.
If you don't like that one, try casino blackjack. You can lose on purpose just by hitting every hand—eventually, you'll go over 21 and bust. But, can you win on purpose? Only to a certain limit. If you aren't a card counter, the best you can do is to faithfully follow "basic strategy." In that case, you'll reduce the house advantage to its minimum possible value—0.5 percent—which means that you'll lose, on average, $1 for every $200 you bet. Any deviation from that will be random luck.
That is: You can lose as much as you want, on purpose. But you can't win any more than the best of the other players, on purpose.
Even though blackjack passes the "lose on purpose" rule, I think most people would argue that it's a game of luck. Even though you can lose on purpose, there's no way to win on purpose ... that is, there's no way to beat the best players by improving your skill.
Why is this, that you can lose on purpose, but you can't win on purpose? In this case, it's deliberate, human-caused. When we invent games of skill, we keep the ones that have an interesting struggle to win. We don't care whether there's a struggle to lose, because, who cares? The object is to win.
Or, you can look at it this way. When there's competition for a goal, it's hard to win, because you have to beat your opponent, who's trying just as hard as you. When there's no competition for a goal—like losing—it's easy, because nobody is trying to prevent you.
If everyone is trying for X, it's hard to be the most X. But it's easy to be the most "not X.”
This seems like it doesn't matter much, but ... there are interesting consequences. Let's suppose that you're a baseball team, and you're trying to decide who to draft. There are 29 other teams competing with you to make the best choice, but nobody competing with you to make the worst choice.
That means it's hard to beat the other teams on purpose. But it's easy to lose to the other teams on purpose—just pick your mother, for instance.
Now, the interesting part. The same thing applies about winning and losing by accident. It's hard to beat the other teams by accident, but it's easy to lose to the other teams by accident.
Suppose you scout a player, and you think he's the next Mike Trout. The other teams are scouting him too. If you're right about him, and the other teams are too, the only way you're going to get him is if you have the first draft choice. Otherwise, some other team will snap him up before you.
But ... suppose he's not the next Mike Trout. You just happened to see him on a day he went 5-for-5 with three home runs. He's really just a fourth-round pick, and you've badly overrated him. What happens? You inevitably draft him too high, and you suffer. You've lost by "accident." By mistake. By lack of skill.
It's hard to win by intention, fluke, or skill—but it's easy to lose by intention, fluke, or (lack of) skill.
Let's suppose your scouting department concentrates on a few players. It spends substantial time analyzing those players, and it usually does OK valuating them.
There's a player named Andrew. The MLB consensus is that he's going to be the 20th pick. Your scouts spent a lot of time on him, and they think he's better than that. Their opinion is that he's actually the ninth best player in the draft.
There's another player named Bob. MLB consensus says he's the 16th best player. Your scouts think he's only the 30th best.