Connect6 improved opening rules, which would you prefer?

Mainly improving the variety of openings, while also considering balance.

1. swap1 (player1 move black1 → player2 choose swap)
   Pros: freedom; Cons: players still mostly choose the center, limited variety;

2. random1 (system random black1 in the center 9x9 area)
   Pros: simplest, same as LG model; Cons: one side may have a slight advantage;

3. swap1pro (player1 black1+white2+black3 → player2 swap)
   Pros: highest variety; Cons: difficult opening, significant advantage with prior research;

4. swap2 (black1 → white2 → choose swap → black3 → choose swap)
   Pros: slightly reduces the threat of prior research compared to swap1pro; Cons: still many weird openings, complex gaming strategy, not favorable for beginners;

5. swap3 (black1 in the center → white2 in the center 5x5 area → black3 → swap)
   Pros: easy to accumulate opening experience, comfortable central opening, better overall connectivity; Cons: slightly complicated rules, not favorable for beginners;

6. others? (prioritize simplicity)

I prefer swap2 but black 1 need to be put at center(swap2_center)

swap2_center can prior research the white2, e.g. 2.e8g13 or other weird, black chooses to swap or not? black1_free can at least require the opponent to prepare a lot of white2.

因為規則討論比較複雜，如果可以我希望能用中文與您討論! :) @eeoo

關於黑1是否限制在中心：我目前是支持態度，目前的階段還在開局探索，黑1的限制並不是讓棋局變得單調可預測的主因，既然開放沒有明顯的好處，那麼維持中心能讓棋局不論在對局上還是研究拆解上，都能統一並且有美感。當時連珠RIF等規則也是認為中心不宜太早開放，弊大於利!

關於白2個選擇權：就如您的開局研究，白2有很多選擇，能導出相當有意思的變化，並且很多對於大多數棋手來說都不容易掌握，所以現階段的規則最好是能夠容許白2有一定的選擇空間與出場機會!

黑3以後，我們可以是為開局階段結束。畢竟六子棋前三手給定，其變化量接近於五子棋前五手給定，兩者相當類似!

所以考慮到以上三點，我傾向於兩階段交換，也就是白2黑3都能自由選擇。

當然我明白，這樣能產生的局面數量是非常可觀的，已經類似塔拉山口那樣的自由度了，其容許的變化遠遠超過目前大多數人的研究與理解，然而我不確定如果套用類似黑3給出兩個路線讓對手則一挑選的"五手二打"方案是否合適，如果五手二打方案能夠讓大多數白2能順利出場，平衡性也不至於失衡，那五手二打方案可能更優於黑3完全自由選擇的swap2

我也非常支持中心开局，但采用黑1(B.1)固定位置的主要问题不是选择太多，而是存在白2(W.2)使得黑3(B.3)极难找到平衡局面，比如2.a6f1这样或分得很开的W.2。当年为什么gomoku要从swap1改进到swap2，就是为了防止这种极容易分胜负的极端情况，如果W.2使得局面不存在平衡点，那么swap可以让W.2开局失败，但如果B.3需要花非常长的思考时间才能找到唯一或唯二的可行点，而且唯一的下法还要连下十几步，对这种预先研究好的局面，谁能玩得下去，因此gomoku_swap2才加了可以另走两子来打破研究。你会下gomoku我给你一个局面你可以试试：1.C3-2.H1-3.M3，你第一次遇到且凭你自己能把开局全部下对吗？

我研究五子棋规则很久了，上面的connect6_swap2实际上不是类似gomoku_swap2，而是类似renju的连换规则，是最复杂的开局策略类型，理论上公平需要换6次，如果固定B.1那么其实和swap1pro_center几乎等价了，因为不熟悉的开局乱开等于速死，还不如让对方多开两手，结果就是一人下了5个子，这样每人都准备一种开局秘技，那就变成研究大赛了，当年renju不就是因为新手开妖刀局速胜种子选手而禁止了妖刀，所以我才会建议专业比赛用更适合的connect6_swap3，这种属于指定开局三手交换类型，这时的平衡局面可能已经上百了，五手两打还有什么必要呢，connect6的5子可行情况可比gomoku多得多得多！

原來如此，你說的對，確實對於特意準備的白2，黑3尋找平衡點非常困難! 如果使用 swap2_center 好像處理不了這類的極端策略，也很難透過縮限白2的範圍來達到目的，這樣對於走黑3的一方是非常不公平的...

不知道如果使用類似5手2打的概念，是否可以限制一些比較離譜的白2，同時也能讓一些比較弱的白2得以出場呢? 我很希望看到更多的白2出場，但又不希望各種離譜極端的白2針對性地出現...

恩，swap3似乎也挺好的，五手二打確實沒必要....

白2限制在5*5的範圍也剛剛好，黑3產生平衡局的難度還在可以接受的範圍，但就是可行的開局太多，怕是對新入門的玩家不友善! 如果是比賽規則，我很支持swap3

不過對於swap3，有個問題讓我感到疑惑。

這個流程相當於B1、W2、B3 都是由同一玩家走出，這樣連走5手似乎對另一方不公平。

如果改成swap2的流程，但是B1限制中心，W2限制5*5，這樣如何呢? (也就是W2、B3結束時都能有swap)

這樣兩邊的選擇權似乎都挺接近的!

不说五手多打这种出于无奈才设计出的鸡肋规则，就说实际操作，你要多麻烦才能显示两打，connect6的两打完全可能两个子在同一位置，你实体棋盘都不一定好摆。

renju五手多打的唯一目的就是增加开局数，connect6两子能形成的开局数比你想象得多太多了，因为renju这类是先第一子再第二子，第一子已经限制了可走范围，不可能出现第一子下了离谱点，第二子对方不去赢你，反而也去下离谱点回归平衡，但connect6同时下两子的类型就可以，所以同时两子的可选点数量远大于先后两子。所以connect6可能存在的平衡点会异常之多，完全没必要去靠多打增加变化。

至于离谱的W.2，即使你设计好三手N打，理论上找到正好第N打唯一的离谱W.2也只是时间问题，现在renju的山口还是塔拉山口比赛，就有第七还是第八打唯一的开局，其他打点均必败或必胜，还经常有选手选错，差不多沦为背定式大赛了。所以五手多打这类是很差的规则类型，你可以学习一下连换规则，根本用不到多打点，依然保证平衡以及最多的变化数量，但这样的坏处就是很难累积研究，类似于chess960。

swap3怎么是同一玩家开出？W.2这些开局，B.3每个都有特殊准备？再说你自己开出的W.2，对方出现很优势的B.3但你又不熟悉你才会交换，不会下优势局当然只能怪自己的W.2准备不足咯。

swap3 (black1 in the center → white2 in the center 5x5 area → black3 → swap)

喔! 我看上述的描述，以為交換的流程只發生在B.3落子後

聽你的描述，swap3似乎在W.2落子後就有交換的機會，如果W.2與B.3都有交換的流程，那就沒問題了! 這正是我希望的~ :)

我把swap3的流程細節具體描述如下：不知道是否與你的意思一樣? 也許有細微差異

The black player puts the first move in the center of the board.
The other player may swap.
The white player will put the 2nd move (2 stone) within 5x5 central square.
The other player may swap.
The black player will put the 3rd move (2 stone) without any limit (or within a finite central square if you prefer).
The other player may swap.

opening stage finished, game start!

不是啊，就是交换只发生在B.3后，只有一次swap，模式和renju的RIF指定开局三手交换一样，所以久经考验了。
swap3 (black1_center → player2 white2 in the center 5x5 area → player1 black3 → player2 swap)

player2下W.2，player1下B.3，没有一个人连下5子的。策略上的话，center 5x5 area一共有44种W.2，player1需要知道每个W.2的至少一种可行开局，而player2可以事先准备某个W.2的各种B.3情况。44种W.2平均可能有5个平衡局，平衡局一般意味着开局三手后依然选择比较多，那么5个平衡局再对应平均5个W.4的话，要准备的开局实在太多，很难精通，而且此时黑方也可以选择有一定优劣势但不至于速败的不平衡开局，用来打对方准备不足。简单来说就是，player2稍有主动权，但预先研究的优势并不大，和目前职业连珠要准备的多打情况可能差不多或稍多些。

至于你说的规则其实就是swap2的区域连换版本，暂时命名为
swap2_area (B.1_center → swap → W.2_5x5area → swap → B.3 → swap)

可以简单分析一下：
B.1后的第一次swap机会没有意义，因为能选自己喜欢的W.2更有优势，正常不会交换；
W.2后的第二次swap机会意义也不大，因为交换等于是让W.2方继续选择B.3，这才是一人下连5子；
去除前两次swap机会后就和swap3一样了，多次选择交换只会使比赛混乱，这也是renju连换规则不流行的原因；
相对的swap2的连换模式，主要是保证娱乐赛能最大程度的自由开局且不至于太离谱，仅是对swap1pro的改进；

另外要提醒一下，connect6连起步都还谈不上，讨论专业性比赛基本是无稽之谈，所以并不一定是越公平越好，光是简洁性这条就pass不少规则了，很多五子棋爱好者来下connect6，就是因为规则简单又能保证一定公平性，切忌本末倒置。

If I may summarise:

In Connect6, we only need a 3-stone opening instead of a 5-stone opening like in Gomoku because the game is a lot more complex with its two-stones-per-move rule.

The proposal here is that the first player places a black stone in the centre, the second places a white stone in the centre 5x5, and the third places a stone anywhere on the board. After the three stones are placed, the second player chooses a colour.

So it’s not actually “swap-3”, but more like “swap-3rd” because the swap option is only available on the third move.

The reason for this proposal is that it allows players to make some opening preparation (on the second move, there are only 9 distinct moves after removing symmetrical positions), but not too much because there are too many possible third stones. At a competitive level, as player 1, you just have to prepare one third stone for each of the 9 second stones.

The swap only happens on the third move because allowing swap after move 1 is pointless because as second player, you would rather play your favourite second stone. Swap after move 2 is also not useful because if your opponent makes a move 2, it means that they have likely studied for it, and you don’t want to allow them to make their favourite follow-up move 3.

Good summary, just a slight misunderstanding in the rules "3-stone" should be "3-move".

Rule swap3 (swap-3rd):
- The first player puts the 1st move (1 stone) in the center of the board.
- The second player puts the 2nd move (2 stone) within 5x5 central square.
- The first player puts the 3rd move (2 stone) anywhere on board.
- The second player may swap (choice color).

(White has a total of 44 openings on the 2nd move.)

Perhaps this rule is too professional? Maybe ordinary players prefer swap1 or random1 instead?

Ah I see. Okay that does make more sense. So five stones total still. Thanks for the clarification.

I remember reading on connect6.org where they also propose a very similar five stone opening, but each player places one stone, so I was probably influenced by that.

But since that is mentioned, do you have any opinions on a single-stone swap-5 opening for connect6? It could be black-white-white-black-black or black-white-black-white-black, but probably the former if we were to maintain the usual stone order.

Yes, I found it. The rule is as follows:
swap-5 (black 1st stone → swap → white 2nd stone → swap → white 3rd stone → swap → black 4th stone → swap → black 5th stone → swap)

It originates from gomoku (https://www.renju.net/rule/27/), it's a very strong rule, but it's too too complex, both in form and strategy. I attempted to improve it a bit:
swap-5_center (black1_center → player2 white2.1 in 5x5 → player1 white2.2 in 5x5 → player2 black3.1 → swap → black3.2 → swap)

It's very similar to swap-3rd and offers a bit better fairness, but it's still somewhat complex. The single-stone opening is an interesting idea, but it contradicts the classic 1-2-2-2... pattern of connect6, lacking a bit of elegance. If one wants to play a wild opening while ensuring fairness, they can try swap-5.

For what it's worth, we now have Connect6 in Abstract Play with the swap-3rd opening as a variant option. You can also play it on a Toroidal 15x15 board. (:

Suddenly remembered, there is also a very unique rule: (by richu333)

swap-2pos (Black1 → Whit2 + swap-position*2 → Black3 → [swap])

The first player puts the 1st move (1 stone) anywhere on board. (or center)
The second player puts the 2nd move (2 stone) and 2 swap-positions anywhere on board.
The first player puts the 3rd move (2 stone) anywhere on board.
The second player may swap if there is any of the 3rd move on the swap-position. (containing symmetry)

Brief explanation:

This rule is equivalent to requiring Black3 to make the Nth strongest move. Therefore, White2 of the 2nd move cannot be too weak, otherwise Black3 would have advantageous choices outside the swap-position.

The swap-position of the 2nd move can also be replaced by forbidden-position where Black3 cannot be placed, thus eliminating the need for a swap. However, drawback of this approach is that it restricts cases where Black intentionally wants to create an unbalanced opening. Additionally, there is a small possibility of opening where, apart from the forbidden-position, all other positions are disadvantageous for Black.

The number of centrally balanced openings under this rule is estimated to be tens to hundreds, which is relatively fewer compared to swap-3rd, which has hundreds to thousands, but it is still sufficient and more conducive to accumulating experience.

In conclusion, apart from being a bit special in terms of process, and not being easy to find swap-positions initially, this is a pretty good competitive rule, concise and free.

Reality: the rules for C6 on littlegolem will probably not be changing anytime soon.
Solution: Go to the super hip site www.abstractplay.com and play swap 3rd variant. That site is adding new games all the time, and they just added C6 very recently. Highly recommended site

abstractplay.com
The first Connect six tournament begins May 4

Oh, I see now. So "Abstract Play" is a new platform. That's cool! Let's try it!

Thanks for the sharing!

легче лопатой вырыть море, чем начать играть на этом сайте.

@ypaul21
Is there still a chance to play Collinear Connect6 (Connect6 one-line) on AbstractPlay?

It's a very relaxed and enjoyable variant because each pair of stones must align on one line, greatly reducing the number of positions to consider. The attacking aspect is also milder compared to traditional Connect6, making it less prone to immediate losses, which is quite suitable for beginners getting into Connect6. Additionally, what adds more fun compared to Connect6 is that in this variant, a 4-in-a-row doesn't need immediate defense; instead, players can utilize the one-line rule to counterattack, adding a significant dynamic to this variant. When initially designing this game, it combined features from three different games (Connect6/Connect5/King-Knight-5), yet the rules remain surprisingly concise, making it a delightful discovery.

Connect6 one-line

There are two additional rules on Connect6:
Each player places two stones on the same line. (- | \ /)
One of the player's stones must be placed on the same line as one of the opponent's last two stones.

(The program flow can also be simplified as follows: The 1st stone must be on the same line as one of the opponent's last two stones, and the 2nd stone must be on the same line as the first stone.)

---

On the other hand, let's also discuss Connect5 (Connect5 two-line). It's essentially a fusion of Connect6 and Renju. Renju involves a prohibition rule for the Black side, while White can win by forcing Black to make a prohibited move. If you enjoy Renju's unique strategy of playing around prohibitions, then Connect5 is almost tailor-made for it. This makes the game quite intense; even a tiny mistake can lead to a series of very strong attacks, and finding these challenging attacks is where its greatest pleasure lies. Its logical depth surpasses both Connect6 and Renju. This game is almost as old as Connect6 and can be considered one of the oldest variants following the 1-2-2-2 pattern.

I think I could look into it. Collider Connect6 should be simple to implement as a variant of Connect6.

Connect5-two-line is trickier to categorise. It doesn’t feel right to add it as a variant of Gomoku because it is closer to Connect6, and at the same time, it doesn’t feel right to add it as a variant of Connect6 because the objective is to get a five-in-a-row. It could also potentially just be a new game of its own, but it doesn’t feel like there’s enough legacy to be a game of its own.

But I’ll think about it.

Oh yeah, does swap-3rd work with these variants? Especially that second move constrained in the 5x5 square part.

Really grateful!

Swap-3rd is always feasible, though not necessarily essential. Connect6-one-line is more freedom, as it's relatively new, there aren't many established opening strategies yet; Connect5 might be a rare variant where White has a slight advantage, so even with swap-3rd, Black doesn't have many choices.

As for the classification of Connect5, those who prefer Connect6 would probably lean towards it more. Also, I've seen examples of variants like Reversi having hexagonal boards, so perhaps Connect5 could be seen as a variant of Connect6? Of course, theoretically, it should stand as an independent game, similar to Pente?

Collinear Connect6 and Non-Collinear Connect5 have both been implemented as variants of Connect6 in Abstract Play. You can use them together with swap-3rd and the 15x15 toroidal board.

Wow, Toroidal Collinear/Non-Collinear? That sounds wild! On a toroidal board, a diagonal line will turn into two lines N spaces apart. But that might add some extra flavor. Good job! Thanks again!

If you are going to have a swap rule... Why are you playing connect6?

The whole point is that the special turn structure would balance the game. Apparently there is large second player advantage, meaning the theory doesn't work, the game is not balanced. (https://littlegolem.net/jsp/forum/topic2.jsp?forum=70&topic=193)

Connect6 is just six-in-a-row, 2 stones per turn, with first player forced to forfeit their first stone as handicap.

That handicap is evidently too large, so if you are going to use a swap rule... just go back to 2-2-2-2-2-2-2-2 turn structure and use swap1.

n-in-a-row with 2 moves per turn is very fun, just go back to the basic version and use swap to balance. Fun thing about two stones per turn is that simple swap 1 is already much more effective for balancing the game compared to regular gomoku.

My bad, black is sente in Connect6, got confused.

Now I get it.. yes it's a bit more of a problem because swap-1 doesn't work well with just one stone

Yes, I've wanted to say about the issue with swap rules for a long time. I thought no one cared.

After in-depth research, the current best opening rule has been found. It is a simplified version of the swap-2pos rule from the posts above, requiring no swap, which I call the Pro rule.

Connect6 Pro
Opening Rule:
The first player places the 1st move (1 stone) anywhere on board.
The second player places the 2nd move (2 stones) and marks 2 forbidden positions for the 3rd move.
The first player places the 3rd move (2 stones) anywhere on board except for the forbidden positions.

It's actually similar to Gomoku official Pro rule, with the difference being that the fixed opening forbidden area is now player-chosen, aiming to dynamically exclude points where the opponent has a significant advantage.

For human players, it's a sufficiently fair rule. Compared to the pie rule, which requires players to more difficultly select a balanced move, the Pro rule allows players to follow their natural intuition and habits, focusing solely on the strongest possible moves. This makes it highly beginner-friendly while offering a cleaner, more flexible set of rules. The only flaw is that a small number of openings may grant a slight advantage to the second player (though not exceeding the first player advantage under the free rule). Overall, it is very worth it for high-level players to be satisfied without a swap rule.

On LG, there is a simple compatibility solution for this rule. You can check out the newly created thread.