Why winner-take-all:
1) It is the only result prescribed in the rules. There is no mention of credit for 2nd or 3rd place in the rulebook for Dominion, just winners (tied or outright). This means that there is no official precedent for having any credit given to players who do not win a game.
2) It is what matters in the latter stages of most tournaments and championships. With a few exceptions, Dominion tournaments are won in a matter of a single game, or a best-of series. To crown a champion, neither of these methods take into account any losers, except for some tiebreakers.
3) It discourages players from colluding with certain opponents to gain a beneficial result for both of them. If you've ever watched a major international soccer tournament, you know that the last two games of the pool rounds are played concurrently. This is meant to mitigate a "common-enough-to-make-a-rule-about-it" situation where the participants of one game will both advance to the next round, regardless of the result of the other game, if they play for a known and exact result.
It happened in 1982 and the rule was instituted, although the phenomenon is not preventable in soccer's current regular tournament format (Euro 2012's Group C had this problem scenario). With a winner-take-all system & a first-to-X-wins format, this problem ceases to exist. Without a first-to-X-wins format, winner-take-all still helps prevent this collusion between, for example, a first and second place player.
If I am playing a tournament or league of anything, I want to be playing the actual game prescribed (Reason 1), not a modified or watered-down version of it. I also want to be playing under as-close-to-the-same rules as possible from start to finish (Reason 2), because with different incentives come different styles of play. Finally, I will be playing to win; if there is some loophole in the format that will guarantee my progression in the tournament, I will take it, spirit-of-the-game be damned (Reason 3). I've done it before, and I'd do it again, because it's the organizer's job to make the rules, not mine. My goal is to win.
As an organizer, these are the primary concerns I have, which is why a winner-take-all system (ideally with a first-to-X-wins series) is the only proper way to organize a Dominion tournament, in my opinion.
Now, to respond (please feel free to respond to mine - I'm trying to be formal and equal, so please do the same for me):Why Point system:
My main reason is that the result reflects more skill than luck. Multiplayer Dominion is a very swingy and luck-dependent game. You can just lose to a newbie with bad draws. 4p game is the most severe, as engines are more unlikely to be built. My experience in multiplayer game is that I am more often powerless to win, but I do have more control not to be last, say in a 3p game. Note that if only 4 wins and 3 wins can proceed this reason is probably not relevant.
I agree that Dominion can be a very swingy and luck-dependent game, and it scales upwards in player count poorly. However, long ago we started having best-of and multi-game series for Dominion, and that's basically become the norm in tournament play. This provides a simple solution for this problem, and retains the game in it's complete form - Dominion is swingy, why prevent that through metagaming? It's just a part of the game, and it still takes a decent amount of skill to see which combo is going to provide your best path to victory.
A slightly less important reason is that point system has less king-making. Basically in winner-take-all, you cannot predict what opponents will do once they find themselves highly unlikely to win. In addition, since in the current format one only faces the same set of opponents, it is unlikely for anyone to have a chance to play suboptimally in order to make his main competitor even less likely to win.
Aside from speaking about the current format, I disagree completely, as the kingmaking is worse with a point system. Assuming everyone plays as optimally as possible, and does not "fall on their sword" so to speak, a winner-take-all system would have everyone not in the lead positioning themselves for the best possible path to victory. This gives the player with the lead the unenviable task of trying to end the game without any help from someone playing poorly.
Having a point system changes this completely. Instead of everyone fighting in their own self-interests, someone with the opportunity to end the game in 2nd place might do so, simply to screw over the two people they are leading. The 1st place player gets a lot more points simply because one of their opponents decided that kingmaking them was preferable to trying to win themselves, and in reality could lead to players without a decent endgame strategy gaining a lot of points simply because their opponents thought it preferable to place 2nd next to them.
This opens up the table for late-round collusion, sub-optimal play, and metagaming. If two players can be guaranteed advancement via an alliance, you have now added politics to the game that DXV tried so hard to make non-political.
A even less important reason is that a point based system has no problem dealing with 3 or 4 players or ties.
I recommended a system almost identical to the old one-off BGGDL system. This would be strictly "winner-take-all," cares about the players that you beat (you winning, them not winning), including shared victory. It scales perfectly and ignores ties.
[snip for brevity]
The only distinction made is between players who won, and players who did not win. According to the actual Dominion rules, there's only one prize handed out: victory (shared or outright). Therefore, winner-take-all seems like the LEAST arbitrary system to employ, in my observation and opinion.
Perhaps, but of course those rules only apply to a single game of Dominion. By the same rules (including Intrigue rules), a single game of (regulation) Dominion cannot determine the winner of a group of larger than 6 players. Therefore, the victory rules in the rulebook cannot apply to a tournament situation. QED.
Agreed, a single game of Dominion cannot determine a winner in a larger group. Furthermore, we generally have no framework for a tournament with >3 players/teams per game. But that doesn't mean that the rulebook is unimportant or should be discarded in a larger tournament setting - we should use it as a framework for organizing. As I state above, once you modify the terms of victory, you might not be playing Dominion anymore.
I should be clear that I don't think it was the non-points system that is arbitrary nearly as much as the only four games and the all of those games with the same players problems, not to mention the seating problem. I actually think all of those trump the winner-take-all problem. But I should have been more clear on that, I think, since I harped on the 4P WTA initially and mainly.
For those of you that want to see a point system: what's the reason?
(I can sum up the points given, but I'm already biased and don't trust myself to be objective about what I don't agree with - so please, someone answer it for me, then ask the same question about winner-take-all)
In my opinion, a multi-game winner-take-all scenario encourages poor play, especially from the fourth seat. There have been discussions about the inherent necessity of taking extra risks from the P2 position in 2P games. That necessity scales with the number of players. In a 4P game, P4 must be willing to take risks that are poor play but might still win the game. Buying two unsupported Maps is, I'm sorry, bad play--but it's good enough, on average, to overcome that huge fourth seat deficit.
It also compounds luck. Consider a series of four games. A player who wins one (say, the one where he started) and takes second in three is, in my opinion, likely to be a better player than someone who wins two games--the one he started, and the one where he lucked into T5 Maps as P4--and came in fourth in the other two. It's reasonable to guess that this player would not have won that game without such great luck. However, that single lucky win bumps him into serious contention.
Both of these can probably be mitigated by more games.
As I stated above, "more games" is generally the norm. However, I disagree with you completely about a 1-3 player with three 2nd places being better than a 2-2 player without - because the objective of the game is to finish with the most VP, and the 2-2 player did that more often than the 1-3 player, that 2-2 player is clearly better at fulfilling the winning objective of the game. Subjectively believing that the consistent 1-3 player is a better player is just that: subjective. The 2-2 player did what was asked - win - more often, and is therefore more likely to win a game.
Expand this to a 400 game series. Is the 100-300 player any better than the 200-200 player?
Also, is there a better argument against winner-take-all in Dominion, specifically, than "2 Treasure Maps?" I'm not a big fan of the card, but everyone still has the same access to the kingdom, right? No matter what you do, you're going to have to choose a strategy that may not pan out. I see Treasure Maps as an indictment against having one-offs, and not against winner-take-all. In fact, Treasure Maps ARE a part of the game, and if you're just implementing a metagaming system to prevent against the 1/12 chance there's a Treasure Map in the kingdom, you might as well just have a rule saying "No Treasure Maps" instead. Seems a little simpler, but still isn't Dominion.
And I see timchen has already noted these, along with the kingmaker argument.
Which I addressed above. I know for a fact that kingmaker would be worse (I'd exploit it, for one) with a point system that gives primary competition credit for non-winning performances. I think, in regards to the kingmaker issue, you're considering the presence of sub-optimal players in a tournament setting. I'm not.
Sub-optimal players exist in the early rounds, but they get eliminated quickly UNLESS you have a system that encourages them to continue playing sub-optimally. That's fine if the format continues in that way, although I'd say you're not playing Dominion anymore, and instead something quite watered down.
Most of the time, halfway through the tournament, you adopt a bracket system and the point system goes completely out the window. You're playing real Dominion again! But you don't necessarily have the best Dominion players in your bracket. And these sub-optimal players could compound the problem by denying a truly strong player advancement through their poor play. It's a slippery slope that leads to either not playing a Dominion tournament as written in the rules, or not having the best players play each other when the games count the most.
Kirian: I agree about the 4p pods being arbitrary. There's nothing about them that doesn't seem that way. I just wish I hadn't misunderstood your comment!