Anyone want to go over this mate? Longest for me!

I was trying to see if this was really a forced mate or if I screwed it up by not seeing a resource for black. As it was, I didn't count on the resources of the black knight, wondered if that was his final mistake, his placement of the knight. I saw three places for it, seemed at least one of them was better. (giving it back).

Event "Clan challenge"]
[Site "http://www.redhotpawn.com"]
[Date "2010.11.19"]
[EndDate "2010.12.03"]
[Round "?"]
[White "sonhouse"]
[Black "HFRJPcheck"]
[WhiteRating "1683"]
[BlackRating "1625"]
[WhiteELO "1683"]
[BlackELO "1625"]
[Result "1-0"]
[GameId "7937583"]

Originally posted by sonhouse
I was trying to see if this was really a forced mate or if I screwed it up by not seeing a resource for black. As it was, I didn't count on the resources of the black knight, wondered if that was his final mistake, his placement of the knight. I saw three places for it, seemed at least one of them was better. (giving it back).

Event "Clan challenge"]
[ c4d5 27. Qd3e4 Kd5c4 28. d5 Kc4c5 29. Qe4d4 Kc5b5 30. Qd4b4 1-0[/pgn]

24.Qf3+ Kf5 25.Qd3+ Kg5 26.g3 and it looks like the king is not long for it.

ps. but you're way looks quicker.

Originally posted by tomtom232
24.Qf3+ Kf5 25.Qd3+ Kg5 26.g3 and it looks like the king is not long for it.

I looked at that, but did not see a way to continue the attack forcefully with the king at g5. There is no decent check in that position and I was afraid if the black knight took that pawn or the queen, I would not have a mate at all, just be two pieces down.

Maybe this helps.

ChestUCI confirmed a forced mate-in-7 starting at move 24. You found it. (Either rook to e1 works, the remaining moves are the same.) I backed it up a move (to move 23) and asked it to find any mates in 9 or less, it didn't find any. If there are any longer mates, it would take the solver too long to find them.

It looks like 23...Ne7 allowed the mate-in-7. Probably 23...Nxc3 was the best move for Black, but even it was losing eventually.

Starting the counting at move 23,

+11.60 1. ... Nd5xc3 2.Qh5f3+ Ke4xd4 3.Qf3xc3+ Kd4d5 4.Ra1c1 Qe8c6 5.Qc3d3+ Kd5xe5 6.Rc1xc6 b7xc6 7.Qd3c3+ Ke5f5 8.Qc3c5+ Kf5xg6 9.Qc5xf8 a6a5 10.Qf8xf4 e6e5 11.Qf4g3+ Kg6f6 12.Qg3f3+ Kf6e7 13.Qf3xc6 Ra8a6 14.Qc6xc7+ Bc8d7 15.Qc7xe5+ Ke7f7 16.Qe5c7 Kf7e7 17.Rh1e1+ Ra6e6 18.Re1xe6+ Ke7xe6 19.a3a4 Bd7e8 20.Qc7b6+ Ke6e7 21.Qb6xa5

I tried to do a pgn of your analysis here but it didn't take. I'll have to do it the old fashioned way, look at a board🙂

Do the pgn format rules go you can't do a board in the middle game without doing the whole beginning, like up to 23? I would have to cut and paste my beginning with your ending?

Originally posted by tomtom232
24.Qf3+ Kf5 25.Qd3+ Kg5 26.g3 and it looks like the king is not long for it.

ps. but you're way looks quicker.

Well, I'm perplexed. (Not too unusual for me.)

I plugged 24.Qf3+ Kf5 into ChestUCI, expecting it not to find any more mates, and heck if it didn't find a mate-in-8 starting at move 24.Qf3+. This conflicts with my previous search that said there was only one mate (mate in 7) at 9 moves or less. So I don't know what to think.

Anyway, the mate-in-8 MIGHT be:

24. Qf3+ Kf5 25. Rh4 Rh8 26. Qg4+ Ke4 27. Qxf4+ Kd5 28. Qe4+ Kc4 29. d5+ Kc5 30. Qd4+ Kb5 31.Qb4#

(Although it looks like there may be multiple branches of the solution starting at Black's 25th move, based on Stockfish analysis.)

So color me confused, I think I'm going to take a break. 😵

Originally posted by Mad Rook
Maybe this helps.

ChestUCI confirmed a forced mate-in-7 starting at move 24. You found it. (Either rook to e1 works, the remaining moves are the same.) I backed it up a move (to move 23) and asked it to find any mates in 9 or less, it didn't find any. If there are any longer mates, it would take the solver too long to find them.

It looks like 23...Ne7 ...[text shortened]... Ke7f7 16.Qe5c7 Kf7e7 17.Rh1e1+ Ra6e6 18.Re1xe6+ Ke7xe6 19.a3a4 Bd7e8 20.Qc7b6+ Ke6e7 21.Qb6xa5

Does your engine give any other alternative to 4 Qe8c6? It seems to just set it up to lose with the next check. That seems to be the camel that broke the straw's back🙂

Originally posted by sonhouse
Does your engine give any other alternative to 4 Qe8c6? It seems to just set it up to lose with the next check. That seems to be the camel that broke the straw's back🙂

You really need to download your own free GUI and engine. 🙂


Alternatives to 4...Qe8c6 are (cut and paste from analysis output, setting on 20 principal variations) :

17 02:17 45.551.108 332.451 +M2 1. ... Qe8d8 2.Kd2d3 Bc8d7 3.Qc3d4+

17 02:17 45.551.108 332.451 +M2 1. ... f4f3 2.Kd2e3 f3xg2 3.Qc3c5+

17 02:17 45.551.108 332.451 +M2 1. ... c7c6 2.Rh1e1 Qe8xg6 3.Qc3c4+

17 02:17 45.551.108 332.489 +M2 1. ... b7b5 2.Rh1e1 Qe8xg6 3.Qc3c5+

17 02:17 45.551.108 332.489 +M2 1. ... Bc8d7 2.Rh1e1 Qe8xg6 3.Qc3c4+

17 02:17 45.551.108 332.489 +M3 1. ... Ra8a7 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:17 45.551.108 332.526 +M3 1. ... Ra8b8 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.526 +M3 1. ... a6a5 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.526 +M3 1. ... Rf8h8 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.565 +M3 1. ... Rf8f7 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.565 +M3 1. ... Qe8d7 2.Rh1e1 Qd7b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.565 +M3 1. ... Rf8g8 2.Rh1e1 Qe8b5 3.Qc3f3+ Kd5d4 4.Qf3e4+

17 02:16 45.551.108 332.565 +M3 1. ... b7b6 2.Rh1e1 c7c5 3.Qc3f3+ Kd5d4 4.Qf3d3+

17 02:16 45.551.108 332.603 +M3 1. ... Qe8e7 2.Rh1e1 c7c5 3.Qc3f3+ Kd5d4 4.Qf3d3+

17 02:16 45.551.108 332.603 +M3 1. ... c7c5 2.Rh1e1 Kd5c6 3.Qc3xc5+ Kc6d7 4.Qc5d6+

17 02:16 45.551.108 332.603 +M3 1. ... Qe8xg6 2.Rh1e1 Qg6c2+ 3.Qc3xc2 Rf8f5 4.Qc2c5+

17 02:16 45.551.108 332.640 +M5 1. ... Kd5e4 2.Rc1e1+ Ke4d5 3.Qc3d3+ Kd5c6 4.Re1c1+ Kc6b6 5.Qd3d4+ Kb6a5 6.Qd4b4+

17 02:16 45.551.108 332.640 +M11 1. ... Qe8b5 2.Rh1e1 f4f3 3.a3a4 Rf8f4 4.a4xb5 Rf4d4+ 5.Kd2e3 Kd5xe5 6.Qc3xd4+ Ke5f5 7.Rc1c5+ e6e5 8.Qd4xe5+ Kf5xg6 9.Ke3f4 f3xg2 10.Qe5h5+ Kg6f6 11.Rc5f5+ Bc8xf5 12.Qh5xf5+

18 02:16 45.551.108 332.679 +86.58 1. ... Qe8a4 2.Qc3c5+ Kd5e4 3.Rc1c4+ Ke4f5 4.Qc5xf8+ Kf5xg6 5.Rc4xa4 Bc8d7 6.Qf8xa8 Bd7xa4 7.Qa8xb7 Ba4e8 8.Qb7xc7 a6a5 9.Qc7e7 Be8f7 10.Qe7h4 Kg6f5 11.Qh4h7+ Kf5xe5 12.Qh7xg7+ Ke5d5 13.Qg7xf7 f4f3 14.Qf7xf3+ Kd5d6 15.Qf3f4+ e6e5 16.Qf4f6+ Kd6d5 17.Qf6xe5+ Kd5xe5 18.Rh1h5+ Ke5f6

18 02:16 45.551.108 332.679 +13.21 1. ... Qe8c6 2.Qc3d3+ Kd5xe5 3.Rc1xc6 b7xc6 4.Qd3c3+ Ke5f5 5.Qc3c5+ Kf5xg6 6.Qc5xf8 Ra8b8 7.Qf8e8+ Kg6f6 8.Qe8d8+ Kf6g6 9.Qd8xc7 Rb8b5 10.Qc7xc8 Kg6f5 11.Qc8f8+ Kf5g6 12.Qf8xf4 Rb5f5 13.Qf4g3+ Kg6f6 14.Rh1h7 g7g6 15.Rh7c7 Rf5d5+ 16.Kd2e2 Rd5e5+ 17.Ke2d3 Re5d5+

Originally posted by Mad Rook
You [b]really need to download your own free GUI and engine. 🙂


Alternatives to 4...Qe8c6 are (cut and paste from analysis output, setting on 20 principal variations) :

17 02:17 45.551.108 332.451 +M2 1. ... Qe8d8 2.Kd2d3 Bc8d7 3.Qc3d4+

17 02:17 45.551.108 332.451 +M2 1. ... f4f3 2.Kd2e3 f3xg2 3.Qc3c5+

17 02:17 45. ...[text shortened]... g6 12.Qf8xf4 Rb5f5 13.Qf4g3+ Kg6f6 14.Rh1h7 g7g6 15.Rh7c7 Rf5d5+ 16.Kd2e2 Rd5e5+ 17.Ke2d3 Re5d5+[/b]

What free GUI and engine? There are free ones? I never pursued that. Is your engine as good as Rybka or Fritz? Thanks for the lengthy analysis, but what do all those #'s mean in front of the moves?

Originally posted by sonhouse
What free GUI and engine? There are free ones? I never pursued that. Is your engine as good as Rybka or Fritz? Thanks for the lengthy analysis, but what do all those #'s mean in front of the moves?

This site has links to a good selection of freebies:
http://freechess.50webs.com/index.html

I like Arena 2.0.1, others may have other favorites. The engines that come preinstalled in Arena aren't quite up to the strength of the ones you mentioned, but they're not bad. And if you're willing to download and install engines from various sources, the latest Stockfish engine is a bit stronger than Deep Fritz 12, and maybe 50 points below Rybka 4. Good enough in my book.

You can get the Stockfish 1.9.1 JA engine here:
http://homepages.tesco.net/henry.ablett/jims.html

And there are lots more engines at the WBEC Ridderkerk site.


Regarding the numbers, in this example,

17 02:16 45.551.108 332.640 +M5 1. ... Kd5e4 2.Rc1e1+ Ke4d5 3.Qc3d3+ Kd5c6 4.Re1c1+ Kc6b6 5.Qd3d4+ Kb6a5 6.Qd4b4+

17 means the depth (in plies, or half-moves) that the engine has searched so far. So 17 plies equals 8-1/2 full moves.

02:16 is the time taken so far to search to that depth. (2 minutes, 16 seconds)

45.551.108 is the total number of nodes searched so far. (European system uses periods instead of commas, so that means 45 million nodes.) I'm not sure how useful this number is, I don't really use it for anything.

332.640 is the number of nodes per second searched. Another not very useful number. It's only really useful to determine if the engine is searching normally.

+M5 means White mates in 5 moves.

Originally posted by Mad Rook
This site has links to a good selection of freebies:
http://freechess.50webs.com/index.html

I like Arena 2.0.1, others may have other favorites. The engines that come preinstalled in Arena aren't quite up to the strength of the ones you mentioned, but they're not bad. And if you're willing to download and install engines from various sources, the latest ful to determine if the engine is searching normally.

+M5 means White mates in 5 moves.

The last two variations aren't mates, right? Can you cut and paste just those moves and have it play out in some GUI? I guess it would have to have the starting position preloaded.

So the first one says 86 and change and the last one 13. I gather that means you are a bunch of pieces up at the end, a totally winning position.

Originally posted by sonhouse
The last two variations aren't mates, right? Can you cut and paste just those moves and have it play out in some GUI? I guess it would have to have the starting position preloaded.

So the first one says 86 and change and the last one 13. I gather that means you are a bunch of pieces up at the end, a totally winning position.

Nope, the last 2 aren't mates. Cut & paste? Hmm, I don't think there's an easy way to paste the variation moves into the game move list, but you could always manually add the moves to the move list.

But Arena does have a nice feature called the Variation Board. You right-click on the analysis window, and it brings up a smaller board where you can step through any of the analyzed principal variations. (Although you can't do any further analysis within the variation board.)

Yeah, +13 = Up a lot of pieces. 🙂

Originally posted by sonhouse
Can you cut and paste just those moves and have it play out in some GUI? I guess it would have to have the starting position preloaded.

I tried this in Scid, and Scid can do it! You can analyze variations in Scid, then add the analysis variations back to the game notation. And you can even go to any move in the variations and start up engine analysis again. Cool! 😏

Originally posted by Mad Rook
This site has links to a good selection of freebies:
http://freechess.50webs.com/index.html

I like Arena 2.0.1, others may have other favorites. The engines that come preinstalled in Arena aren't quite up to the strength of the ones you mentioned, but they're not bad. And if you're willing to download and install engines from various sources, the latest ...[text shortened]... ful to determine if the engine is searching normally.

+M5 means White mates in 5 moves.

Oooh, nice post! Have been in need of an engine for analysis for ages! Got to love a freebie. I've downloaded Arena with Stockfish, though i'm a little uncertain if i've done it all correctly as i just got a draw against it which shouldn't really happen..