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Topic: Skewing the wedge in favor of P2, how challenging is it?
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watsu

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Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 3, 2017, 7:33 AM

For the last little while I've been working on the idea of what sort of minimal rule changes/variants or combinations would be needed to turn a single wedge line from a sure P1 win to a sure P2 win. In my opinion, Keryo, G and D Pente are unnecessarily strong rule changes for this purpose; a pure wedge line can't be played in G due to P1 restrictions. I'm not terribly experienced with Keryo, but looking at the database P1 appears to win more than half of the hammer games played here, so playing wedge may not even be necessary in Keryo. In D pente, the person who offers a wedge position to their opponent will generally simply end up playing from P2's side of the board, so it's not a sensible line for that variant. Looking at some current variants and games below, I'll start of with a couple of Poof Pente boards which have altered wedge lines from regular Pente games and follow up with boat pente in a second post.




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watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 3, 2017, 7:59 AM

A couple of boat Pente lines which favor P2; the first one of these is a game I recently lost as P2 in regular Pente but would have won had the line been played in boat Pente and the other one is a game which Zoeyk played several years ago, losing as player 1.







Hopefully these few examples successfully illustrate that a game variant combination of Poof-Boat-Pente has a more limited number of winning lines for P1 in some frequently played wedge lines. If any single wedge line (e.g. 7. ... M13 after 1. ... L9 wins for P2 regardless of what P1 does next) were shown to be a sure win for P2 in a variant or hybrid game (perhaps Boat-Poof with overlines not winning? IDK), this would radically alter current Pente game theory in terms of translating it into that variant, since wedge was developed as an avoidance of the hammer. P1 would need a new winning second move after K9, L9, M9 and N9 (to name just a few P2 first moves).


Message was edited by: watsu at Sep 3, 2017 7:59 AM


Message was edited by: watsu at Sep 3, 2017 8:32 AM


I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 3, 2017, 5:22 PM

Here's a variant which I proposed at Brainking about 14 or 15 years ago - give P2 an initial captured pair before the game begins, so that P2 only needs to capture 4 more pairs in order to win the game. At the time, Dmitri King felt that this would give P2 too much of an advantage, since it would skew many wedge lines in favor of P2, but since that is exactly what I'm attempting to accomplish in this thread, I thought I should mention it as a possibility, although it may prove to be overkill for what is needed. If it would alter opening theory so that wedge became a sure loss for P1, it would be interesting to see how it might alter other lines which developed as a wedge alternative. If it gave P2 too much of an advantage with opening move restrictions placed on P1, those restrictions could be altered or removed. Any of these ideas could be tried out either as sets of games with each player playing both sides in rated games as we currently do here, or if the game seemed fair enough for both sides rated single games could be tried with the successfully fair variant. I think that while set play has allowed the rating ceiling issue Pente used to have here to be lifted to a large degree (Gary Barnes, AKA progambler estimated that the pre set rating ceiling was about 2100) sets seem to have decreased the number of live games being played here, which is a shame. It would be nice to be able to pop in to the game room with 10 minutes to kill and play a speed rated game.

I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 6, 2017, 11:56 PM

I'm not as familiar with the hybrid game of Boat-Poof Pente as with either of its component games, but here is a position which has lines which win rather quickly in Pente, Boat Pente and Poof Pente, but where poofs have the potential to interfere with at least one Boat Pente line and Boat rules can interfere with at least one winning Poof Pente line for P1.



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dmitriking

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 8, 2017, 4:30 PM

Interesting ideas presented here, I would be curious to see how this develops.

I agree about real-time games, it was fun back in the day when there would be 10 or 15 people logged in to the game room playing real-time games.

I'd be happy to play some but I cannot get the game room to load, and I don't feel like dealing with Java issues which I find very frustrating.

watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 8, 2017, 5:26 PM

I had difficulty loading the game room for quite awhile as well, but once I installed the game room on my desktop (link directly below the join game room button) I haven't had issues. Before that I tried several different browsers, updating java, etc. without success.

I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 16, 2017, 6:32 AM

Assume the following boards are for boat-poof pente so that threatening to capture a pair with a move to O12 doesn't pan out for P1 due to a poof situation at L12.
Assume as well that for some unknown reason P1 isn't allowed to win by playing to N9 at move 16 or thereafter (IDK, nearsightedness perhaps?) These boards show how lines which win in regular pente can fizzle out in boat (or boat-poof) pente. I'm not certain of the outcome on the second one at this point,
but P2's J7 appears pretty successful in neutralizing some clear winning threats by P1 at this point.







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watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Sep 17, 2017, 9:20 PM

After finding the win for all variants (including ninuki renju, though I didn't mention it in the last post)in the position in the previous post I decided to look at the position with a pair handicap for P2 before giving up on it entirely.
I found the results interesting - an easy win for P2 in Pente and poof Pente if P1 tries the move which would work without the handicap. However, P1 still wins the game in boat, boat-poof, ninuki renju and poof ninuki renju, which leads me to believe (very tentatively based on very little data) that a pair handicap may not be too much for P1 to allow in at least some Pente variants. Much more research and/or play would be needed to verify whether or not this is the case. I'd be interested in playing some games (preferably either boat or poof, but pente would be okay too) with the pair handicap (unrated until the variant is official) if anyone else wants to do some play testing.


Consider the above board to be poof-boat pente or poof ninuki renju; other variants will win (or lose) more quickly and easily along similar lines.


Message was edited by: watsu at Sep 17, 2017 10:02 PM


I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
dmitriking

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 4:25 PM

I am finally getting a chance to look at these, now that I have some experience with unusual situations with poofs and boats.


In reply to the September 3rd 12:33 post (The first one in this thread):


The first one works for black IF white plays 8. M9, a move I am not a big fan of. I seem to recall that O6 is the optimal move. What happens if White plays 8. O6?

For the second game, I'm confused about the result of move 14. M13 by White. Why is that a poof? The order of priority lists attacking captures as occurring first. Doesn't that mean black's N12 stone is gone, and cannot be used to POOF white's M13 stone? I envisioned a "capture-poof" scenario as one in which the poof is caused by stones not part of the initial attacking capture (for example, if they were on a perpendicular line or at a 45 degree angle).


Message was edited by: dmitriking at Oct 1, 2017 4:25 PM


dmitriking

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 4:38 PM

In response to the September 6th post: I'd have to look at it further, but it seems to be that white can win with 16. Q11 (the powerfully aligned tria formations resulting in a double keystone capture.)

dmitriking

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 4:41 PM

In response to the September 3rd 12:59 AM post:

In the first game, I think white wins but misplayed move 18.

The second game is interesting. Are white's 11th and 12th moves optimal?


Message was edited by: dmitriking at Oct 7, 2017 1:20 AM


watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 6:04 PM

"The first one works for black IF white plays 8. M9, a move I am not a big fan of. I seem to recall that O6 is the optimal move. What happens if White plays 8. O6?"
I agree that this line isn't an optimal one for P1. I think there are two separate themes in this thread, which I didn't clarify earlier.
First off, do the variants make certain winning P1 wedge lines (whether optimal or not) in Pente lose in variant play. I think the boards posted demostrate that the answer to this is yes.
Secondly, does P1 still have optimal winning lines of play in the wedge in the variants (which may or may not be obvious). I think so far I would answer that question with a yes based on my analysis, but given a pair handicap for P1, the answer is much less clear.
ETA: re second game confusion - poofs and captures are given equal priority weight when one plays into a poof, since when we initially developed the game we couldn't decide on whether or not any captures made while playing into a poof spot should be taken or not. This equal priority weight is what can lead to 10-10 capture scores, where play then continues until one player has an advantage.


Message was edited by: watsu at Oct 1, 2017 6:41 PM


I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 6:40 PM

"In response to the September 6th post: I'd have to look at it further, but it seems to be that white can win with 16. Q11 (the powerfully aligned tria formations resulting in a double keystone capture.)" 16. Q11 looks good (at least without an initial pair handicap for P1). I have seen what also looks to be a winning 16th move at K11 which appears to work against all variants (but only against some if P1 starts the game with a pair handicap).


Message was edited by: watsu at Oct 1, 2017 6:59 PM


Message was edited by: watsu at Oct 1, 2017 7:00 PM


I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Registered: Dec 16, 2001
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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Oct 1, 2017, 7:05 PM

"The the first game, I think white wins but misplayed move 18."
P1 might well have played differently on or before the 18th in an actual Boat Pente game, but had a winning continuation after the 18th in Pente.

"The second game is interesting. Are white's 11th and 12th moves optimal?"
I thought this was an interesting game as well. Good question regarding white's 11th and 12th. Zoeyk would likely have a better idea than I about that.

I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
watsu

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Re: Skewing the wedge in favor of P2, how challenging is it?
Posted: Jan 31, 2018, 2:31 AM

This game really deserves an analysis thread of its own and Dmitri and I haven't finished exploring all the potential endgames after P2's 21st move, much less before that. Is there a different P1 12th that would work better? A different 8th or 9th move? J7 as a 9th move doesn't seem (so far) to work.
Game ID 50000000206442


Note that while the analysis is incomplete on this game, 21. ... P12 (or N14) are likely preferable for P2 in order to prevent P1 from playing 22. P12 after 21. ...N12. P2 MAY be able to prevent a sure P1 win after 22. P12 with 22. ... F5, but at best the game looks long with the outcome unclear after 22. P12.
Message was edited by: watsu at Jan 31, 2018 2:33 AM


Message was edited by: watsu at Feb 3, 2018 12:16 PM


I don't want to play non tournament rules games. If you take one of my unrated invites, play tourney
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