As I said elsewhere and Chrispminis quoted: As you can see from the article below by Calhamer himself the PPSC vs WTA debate is hardly a phpDip assault on the traditional hobby, it's a long debate which is more or less a matter of opinion, and that's why we offer both

http://www.diplom.org/~diparch/resources/calhamer/objectives.htm


What I'd like to expand on here is you say PPSC makes phpDip a variant of Diplomacy, but I don't think it does because Diplomacy doesn't say anything about draws or second places. Even the creator wasn't sure about it as Edi has said, and as his own article says.
What this means is that for you WTA is a preference; it isn't an inherently correct choice

Second: PPSC is, at least, a necessary evil. If a player has to win to gain any number of points they are less likely to stick around and participate, they are more likely to join many games at a time and give up the moment they think they aren't going to win

PPSC really is what keeps the newer players playing until the end; the people who have been here long enough to see the games before and after points were introduced will be able to back me up here. Without it, and with the larger proportion of new players we have, all games are totally chaotic and terrible

With it those who have some skill can gain some points and make it to the better games, of which a larger proportion are WTA (but there is a choice, and even tournaments are organized), and there's no problem of everyone leaving the games when they're going to lose because people are more skilled and experienced at higher levels

This setup is naturally frustrating to experienced players who are new here, because they have to make it through the filtering process which is our points system, but that's a necessary side-effect of having a fresh, open, large community with lots of new players

If you're an experienced player one option is to leave for a site which has an older, more experienced, smaller community. Another is to battle it out and try to make it here, and try and influence the new players and make more WTA games here.
My point is that crippling this site's point system and making this site into an older, more experienced, smaller community isn't an option, because this site is about offering Diplomacy to everyone. I think given that constraint our choices regarding points systems are pretty reasonable and successful

I'd like totake a swing at answering your questions one by one, from my point of view.

1) what is the purpose of the ppsc system?

It is a way to distribute the points invested by the players in a game. It's not inherently better than WTA, but it's not inherentely worst. Hence, the ability to choose between one or the other.

2) what benefits does it offer over a wta-only system?

Well, PPSC let's players be rewarded for a good game being played, even if they didn't end up on top. This is something that is usually a good thing, specially when the player is new to the game, or in other circunmstances such as a middle class player daring to play the top rankers. Wouldn't you want to reward that guy if he did a good job?

Also, it makes for players fighting things to the bitter end. If you survive with at least one SC, then you got something out of that game, as little as it may be. In WTA, when you know you can't win or force a draw, you've got nothing to play for except what you may consider honor... and many players (particularily the newer ones) don't seem to have much of that.

I know that you can describe the benefits for a WTA, that's why you like it, but PPSC has benefits that are neither better nor worse than WTA's, they're just different.

3) can we achieve those same benefits with a purly wta-system?

No, we can't. How could we? You call PPSC a variant, and I'm not completely disagreeing with that view (I would call both PPSC and WTA specific houserules to adress something the original game does not, wich is a ranking method). Can you create the same feeling as in a gunboat game but with people talking to each other privately?

If the answer is no, then you can't get the same things you get out of PPSC in WTA. Sorry.

4a) if so - how difficult is it to program?

4b) and how difficult will it be for the community as a whole to transition?

4c) if not - what other proposals can be made to cover those benefits without losing the wta nature of teh game?

I would say:
1 - Allow players to create WTA games as soon as they have finished a single game (No newbies creating WTA, as explained before, PPSC is best for newbies, but to be under 100 D does not make you a newbie).

2 - Display 4 sub-tabs in the Joinable Games tab:
a - WTA
b - PPSC
c - CD's
d - All of the above
With PPSC being the default shown for new players.

3 - Stop whining about what people do when you are not forced to join their games. You like playing WTA, you can play WTA, give the rest of us a break.

Sorry to come late into the discussion, but I did make a proposal last year that players be allowed to start WTA games with 45% of their current points even if they had 100 points or less. At the time Kestas said he would accept that code change if anyone wanted to make it. I think this would solve the problem.

Sorry, but what does WTA and PPSC games stand for?

Winner Takes All - all the points to first place
Points Per Supply Centre - you get the same fraction of the points for each supply centre you control (this is generally 1/34, but in special cases can be slightly higher, such as if there are still neutral SCs)