Some gomoku games analysis
Posted:
Nov 13, 2023, 1:30 PM
My opponent starts with a renju opening, stones are close to each other. There is only one opening that doesn't provide a decisive advantage to the first player so I will have to suffer here for a while. OK. 5-K8 is the easiest way to win here; M10 should be sufficient too. Both are bad in renju. M11 is equal in renju so it should be good (maybe winning) for the first player in gomoku as well. A common plan for this 5-moves-position in renju looks like the following: https://www.renju.net/tournament/2448/game/101704/
--- Oh my, I wrote "m=k10,l11,m8,j11,m10,k11,m11,m9,l10,j10,j8,k9,l8,k8,l7,o10" in the game tag, the diagram showing looks broken. Nevertheless, the order of moves is correct, the position is just shifted. ---
After 10 stones being placed (10th move in renju/gomoku, 5th move on this site) there are many options but all of them are not so good in renju. Nevertheless, this particular attack from the renju.net game should be winning in gomoku with a perfect play.
Back to the game. So, hey, I'm trying to weaken my opp's stones with L10 instead of playing a horizontal three. We have some optimal play until my 6th move. My opponent has a very strong position; I see no active defense so K8 looks like the best option. The typical reply should be either 7.H11 (destroying my last activity and dominating the whole board) or smth like 7.M8. It leads after 7. ... H10 8. G11 L12 to some counterplay for white but I doubt there is a decisive attack so Black should win eventually as well. My opponent plays 7.L12, and, well, it's not a bit worse than two moves mentioned above. I have to cut the connections with the right flank so 7. ... N10. Possible 8. H11 looks much stronger now. For 8. ... N7 continuation there is a good option to reply 9. O7 defending the position. Black has some attacking potential but I don't see any winning development here.
Weather changes after 8. K7. White didn't throw a stone on the left flank at H11 or G11 so I feel comfortable there: no opp's threats, some connections for me. So I play 8. ... N7 to disable opponent's resource and prepare some development on the right flank. The goal is to block opp's pair (J12+L12) playing on the right and then play smth like G8 eventually.
9. N8 is the best option, of course. 10. O9 gives me an opportunity to get more space on the right flank; instead, P9 looks stronger. After 11, it looks like I can try to win in the top-right corner but I don't see a powerful enough attack. So I play very calmly 11. ... L6. Is it a good move? I doubt it =) I've lost the precious tempo. My opponent may switch to 12. K13, 12. H11 or smth alike thus launching a devastating attack since I don't see a VCT* threat for me. But after 12. K12 M12 I do! A simple threat emerges: I can play P10 creating two threats: 3-3 at P12 and 4-4-3 through Q10, O10. No defense here. So my opponent replies with 13. N11 (?). Now the whole flank is mine: 13. ... P13. It's better than O12 or O11 because it provides me with a lot of space and new lines. My troyak N7-O8-P9 now works not only for Q10 but for R11 as well.
By Q11 I disable last opponent's active defending options and now I'm ready for a carnage. 15. Q10 blocks my main attacking resource but it's already too late. With O14 I can create a lot more resources. Look at the position: there are 2 black stones alone in the attack. More, the two closest stones are also black! And they form a good shape. IMO, this position have to be won already with a perfect play.
Still, maybe 15.N15 could give some hope to the defending side; N13 is a one more too-much-inside-the-position move. No defense after 18. ... P12, I've calculated all the consequences. It's quite easy: there is a main threat, N14+P11+P14 (or N14+P14), also I have O12 P14 Q13 which makes O13 impossible. So 19.P11 is the most robust defense but after 20. ... Q12 there are two independent threats: 3-3 in N14 and VCF by R15, Q15, P15, S12. There are more threats but it's enough to have two independent. My opponent plays 3 but misses my VCF*. The game is over.
*VCF -- victory by continuous fours. This is an equivalent for playing a 3: if opp is trying to play his own 3, he loses. *VCT -- victory by continuous threes.
Message was edited by: owen_ at Nov 13, 2023, 1:32 PM
Re: Some gomoku games analysis
Posted:
Dec 14, 2024, 2:47 PM
Well, once more 5th Indirect opening. Here, on pente.org, no opening rules are implemented for gomoku, so I appreciate when people start with equal openings instead of surewins. After M11 the opening is playable with some advantage for white which is completely OK for me, let's fight. Moves until 4th are the best development for both colors in renju. 5. J13 looks too straightforward, I'd suggest J12 or L9. But my reply was weak: I've underestimated 5. ... J12, my K11 was way too passive granting my opponent a persistent positional advantage. Then white carefully remove all the countering possibilities for me and get a crazy advantage after 10. Every part of the board is white now. F12, F13, N8, N9, N12, O8 -- everything looks very promising. But... 11. G10 (?). I don't understand it's purpose. This move gives me an opportunity to start some counterplay eventually by G11, G9 or smth alike, it spoils 10th row. And the next move, 12. N9, is clearly better without 11th because my stone disrupts a diagonal connection. My reply is quite optimistic, I don't want any passive block like N8: white controls too much space already. Now for 13th move the best choice for White could be L9, disabling my counterplay. 13. M7 lowers the tension because of resource exchanges.
For 16th move I had generally two directions: black may either launch an attack after 16. ... G9 (in case of 17. O8 etc. black win after 18. ... H9 19. ... F8 20. ... E9 or F9). Or black may try to stabilize the position and defend in the bottom right corner. I don't like to gamble so I chose the second approach. In the real game with at least half an hour left on clock I'd rather go for an attack... but who knows.
Anyway, after 17 moves the position is still quite "white". And... 18. M9 (?) misses the remnants of the advantage. I was expecting 18. M5, so I play this move quickly. The plan was 18. ... M5 19. O7 P6 20. O5 P7, it looks like some equal struggle for the initiative, but white respond 20. M7?, which is clearly bad: this stone can't affect the board since it's deeply inside the position. It blocks one black line and that's all. O5 achieves the same but also creates a vertical pair and blocks my diagonal, so it is just better. White's domination which lasted for 15 moves comes to the end.
Now I finish surrounding ex-active white group and ready to strike. But... I've found all the necessary ideas but failed to find the win, which is easy and nice: 23. ... O10! 25. P9 is the most robust defence here, and I make the next mistake: 25. ... O4 (?!). From the human's point of view, it's a good move: I remove some activity, force my opponent to reply on the bottom and then I'm going to press further on the right part of the board. But the computer analysis after the game showed me a nuance: 51. P13! with an idea on any attack at the bottom like 51. ... M4 52. N5 L4 53. K5 J4 to play 54. Q10 R11 (O8 loses after the VCF threat 55. P11) 55. M6, thus defending both flanks. I didn't see this abuse of the diagonal as well as a winning attack with 25. ... Q10, it's too complicated. So my play is pretty straightforward: 26. ... N13. 27 is the best answer, but for 28 white should prefer some blockade like P13. White play 28. S8 which is losing, but I make a blunder and reply 29. ... O14?? 30 is correct (white need a diagonal cut with M8 and N9 along with a vertical P, so it is necessary), but 31 completely turns the tides from win to loss. I didn't see it during the game, it is the thing I know from the post-game analysis, but white are about to win here! The key is that 31. P13 gives white a VCF threat which can only be blocked passively. The most robust variant is on the diagram:
---- Hope the diagram works, otherwise here are the moves: k10,l11,m8,j11,m11,m10,k12,k9,k13,k11,h11,j12,j10,j14,h13,j13,j15,h12,k14,k16,g10,h10,n9,l7,n7,l9,n8,n10,k8,l8,l10,n6,l6,o9,m9,m5,o7,p6,m7,p8,q7,p7,p5,o6,q6,q8,r9,o12,p9,o4,n5,n13,q10,o8,s8,m14,l15,o14,p11,t7,p13,q12,t9,r7,o11,m12,p15,p12,n12,q9,l14,m13,m15,n15,l16,l17,h16,g17,h15,k15,h17,h14,h19,h18,o13,p14,k17 ----
But that was only a variant, White replied 31. R7, so the crucial R row is blocked now, and P13 doesn't produce a VCF threat. After 31. ... P12 the game is over: unless White will call for some kind of divine intervention, Black are about to play their VCT. Here we had several undo-s, my opponent tried to win by overline etc, and I was hoping that he can find a miracle, but there were not any.
And now just a tl;dr version: my crucial strategic mistake at 5th move; good moves from White and dominance before move 11; 11 looks inoptimal but White still has big advantage; after 17 White is still favourable; White's 18 and 20 are too passive, so Black has an advantage after 21. Black missed a simple direct win on 23, both colours missed an interecting tactical nuance on 26. Then White could win on 31 but played a wrong 4 (never play fours if they are not necessary!) and lost quickly.
Re: Some gomoku games analysis
Posted:
Dec 14, 2024, 2:54 PM
One more try...
Well, once more 5th Indirect opening. Here, on pente.org, no opening rules are implemented for gomoku, so I appreciate when people start with equal openings instead of surewins. After M11 the opening is playable with some advantage for white which is completely OK for me, let's fight. Moves until 4th are the best development for both colors in renju. 5. J13 looks too straightforward, I'd suggest J12 or L9. But my reply was weak: I've underestimated 5. ... J12, my K11 was way too passive granting my opponent a persistent positional advantage. Then white carefully remove all the countering possibilities for me and get a crazy advantage after 10. Every part of the board is white now. F12, F13, N8, N9, N12, O8 -- everything looks very promising. But... 11. G10 (?). I don't understand it's purpose. This move gives me an opportunity to start some counterplay eventually by G11, G9 or smth alike, it spoils 10th row. And the next move, 12. N9, is clearly better without 11th because my stone disrupts a diagonal connection. My reply is quite optimistic, I don't want any passive block like N8: white controls too much space already. Now for 13th move the best choice for White could be L9, disabling my counterplay. 13. M7 lowers the tension because of resource exchanges.
For 16th move I had generally two directions: black may either launch an attack after 16. ... G9 (in case of 17. O8 etc. black win after 18. ... H9 19. ... F8 20. ... E9 or F9). Or black may try to stabilize the position and defend in the bottom right corner. I don't like to gamble so I chose the second approach. In the real game with at least half an hour left on clock I'd rather go for an attack... but who knows.
Anyway, after 17 moves the position is still quite "white". And... 18. M9 (?) misses the remnants of the advantage. I was expecting 18. M5, so I play this move quickly. The plan was 18. ... M5 19. O7 P6 20. O5 P7, it looks like some equal struggle for the initiative, but white respond 20. M7?, which is clearly bad: this stone can't affect the board since it's deeply inside the position. It blocks one black line and that's all. O5 achieves the same but also creates a vertical pair and blocks my diagonal, so it is just better. White's domination which lasted for 15 moves comes to the end.
Now I finish surrounding ex-active white group and ready to strike. But... I've found all the necessary ideas but failed to find the win, which is easy and nice: 23. ... O10! 25. P9 is the most robust defence here, and I make the next mistake: 25. ... O4 (?!). From the human's point of view, it's a good move: I remove some activity, force my opponent to reply on the bottom and then I'm going to press further on the right part of the board. But the computer analysis after the game showed me a nuance: 51. P13! with an idea on any attack at the bottom like 51. ... M4 52. N5 L4 53. K5 J4 to play 54. Q10 R11 (O8 loses after the VCF threat 55. P11) 55. M6, thus defending both flanks. I didn't see this abuse of the diagonal as well as a winning attack with 25. ... Q10, it's too complicated. So my play is pretty straightforward: 26. ... N13. 27 is the best answer, but for 28 white should prefer some blockade like P13. White play 28. S8 which is losing, but I make a blunder and reply 29. ... O14?? 30 is correct (white need a diagonal cut with M8 and N9 along with a vertical P, so it is necessary), but 31 completely turns the tides from win to loss. I didn't see it during the game, it is the thing I know from the post-game analysis, but white are about to win here! The key is that 31. P13 gives white a VCF threat which can only be blocked passively. The most robust variant is shown on the diagram:
But that was only a variant, White replied 31. R7, so the crucial R row is blocked now, and P13 doesn't produce a VCF threat. After 31. ... P12 the game is over: unless White will call for some kind of divine intervention, Black are about to play their VCT. Here we had several undo-s, my opponent tried to win by overline etc, and I was hoping that he can find a miracle, but there were not any.
And now just a tl;dr version: my crucial strategic mistake at 5th move; good moves from White and dominance before move 11; 11 looks inoptimal but White still has big advantage; after 17 White is still favourable; White's 18 and 20 are too passive, so Black has an advantage after 21. Black missed a simple direct win on 23, both colours missed an interecting tactical nuance on 26. Then White could win on 31 but played a wrong 4 (never play fours if they are not necessary!) and lost quickly.
P.S. Moves for the variant on the diagram: k10,l11,m8,j11,m11,m10,k12,k9,k13,k11,h11,j12,j10,j14,h13,j13,j15,h12,k14,k16,g10,h10,n9,l7,n7, l9,n8,n10,k8,l8,l10,n6,l6,o9,m9,m5,o7,p6,m7,p8,q7,p7,p5,o6,q6,q8,r9,o12,p9,o4,n5,n13,q10,o8,s8, m14,l15,o14,p11,t7,p13,q12,t9,r7,o11,m12,p15,p12,n12,q9,l14,m13,m15,n15,l16,l17,h16,g17,h15,k15, h17,h14,h19,h18,o13,p14,k17
