Talk:Fork (chess)

Quadruple forkchecking (sic)

Aren't there some opening traps that involve queen forks that would make a good example. ... I've had both of these happen to me:

• n. Qh5+ ... n+1. Qxe5
• m. ... Qe5+ m+1. ... QxRa1

If nobody has a ready example, I'll try to dig one up... Jeff 18:24 Feb 20, 2003 (UTC)

There are a couple of almost unbelievable examples of this sort of thing from games at quite a high level. Combe-Hasenfuss, Folkstone Olympiad 1933 went 1. d4 c5 2. c4 cxd4 3. Nf3 e5 4. Nxe5 Qa5+ 5. resigns. This is given in Mike Fox and Richard James' The Complete Chess Addict (1987) as the shortest ever loss by a master. I'll let somebody else put it in the article if they want, though—I'm not sure how to best format it. --Camembert

Postscript: see World records in chess for a shorter game with a similar fork. --Camembert

After only a few times playing over IRC, a long time ago, I once quadruple forkchecked him with my knight, checking his king (duh), queen, rook, and pawn. Is that good? :) lysdexia 03:52, 12 Nov 2004 (UTC)

Example queen rook fork

i'm not really into chess algebra, but shouldn't it be Nd2 instead of Nd3 -- the knight is on f3, so he can't move along line 3 can't he?

Besides, it is perhaps not impossible that after a king queen fork, you don't loose your queen. This happens when moving your king opens the way for a piece that checks the other king. --Selach 23:43, 25 March 2007 (UTC)

No. First the knight moves to f2, then to d3 to fork the queen and rook. Bubba73 (talk), 02:58, 25 April 2007 (UTC)

Lead image

Black's pawn fork isn't mentioned in the lead image caption. Doing so would make it even longer, so perhaps those three pieces should be removed altogether? —JAO • T • C 04:34, 7 August 2009 (UTC)

I think that caption is too long as it is. I think it would be better to shorten the caption but discuss that example more fully in the text of the article. Bubba73 (talk), 23:19, 7 August 2009 (UTC)

Yes, that sounds like a good idea. —JAO • T • C 08:15, 8 August 2009 (UTC)

forked pieces must be undefended?

Not sure if "undefended" is proper chess terminology; by "piece A defends piece B", I mean that if B were taken by piece C, then A would be able to take C immediately. Is it considered a fork when one or both of the attackable pieces is being defended? Is there separate terminology for when one or both of the attackable pieces is defended? If so, the intro should mention them, because they would be closely related to forking.--Danielx (talk) 02:09, 7 March 2011 (UTC)

You are right - the forked piece could be defended, but more valuable than the attacking piece. Bubba73 ^{You talkin' to me?} 03:16, 7 March 2011 (UTC)

removed material, etc

I removed most of the caption to the first diagram as discussed on the Chess project page.

(It is particularly effective to fork a king and another piece: the rules require immediate attention to a check to the king.) Black cannot choose to defend another piece, nor can he make an intermediate move (zwischenzug) to complicate the situation; the king must move, after which White can capture the rook. In return, ... . But White can escape loss of material, since after Black's king moves out of check, one of the rooks can deliver check again, allowing the other rook to escape next move, and possibly check the black king again, allowing the white knight to capture the black rook.

The reason is that the caption is too long. At this point, forks should be illustrated, but the caption went too far. I think the removed material about intermediate moves, etc, should be discussed in a section in the body, but not here and not with this example.

I also removed the white king from the diagram because this is not intended to represent an actual position - just show the forks.

I also don't see the need for the second diagram (which has now been removed). Bubba73 ^{You talkin' to me?} 22:59, 7 September 2012 (UTC)

Article needs

After all of the revisions, I think the article needs two things:

1. An example (with diagram) showing an escape from a fork, preferably from a master game.
2. inline references. Even though most references are going to say about the same thing about forks, a few inline references will help it get to a higher class. Bubba73 ^{You talkin' to me?} 04:25, 9 September 2012 (UTC)

Fork trick example from the opening

I think we should include a fork trick example in the opening, using the knight capture followed by pawn fork to regain the piece and eliminate a center pawn. The simplest example seems to come from the Three Knights Game: 1. e4 e5 2. Nf3 Nc6 3. Nc3 Bc5(?) 4. Nxe5 Nxe5 5. d4. There are similar examples where Black can use the fork trick in the Vienna Game, Two Knights Defense, and Bishop's Opening, but they seem to be messier as there are a lot of alternatives to explain. I'll take a crack at this if no one else does it, although I suspect someone else here could do a better job than I can. Quale (talk) 07:41, 9 September 2012 (UTC)

Another simple opening example from the Ruy Lopez Exchange Variation: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 and 5. Nxe5 does not win a pawn because of the queen fork 5...Qd4. Quale (talk) 08:18, 9 September 2012 (UTC)

I think that is good. Bubba73 ^{You talkin' to me?} 02:45, 10 September 2012 (UTC)

I'd vote for Two Knights (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Nc3 Nxe4) over Three Knights, since the line comes up a lot in amateur play. (Whereas Three Knights, is less commonly seen.) I think the messiness in Two Knights could be sufficiently controlled. Ihardlythinkso (talk) 04:33, 10 September 2012 (UTC)

That is good because the "fork trick" is mentioned in that section. In fact, this article could have a section "The fork trick". Bubba73 ^{You talkin' to me?} 04:59, 10 September 2012 (UTC)

Do u think desirable to have Two Knights example only, or two examples, Two Knights and Ruy Exchange? Ihardlythinkso (talk) 05:38, 10 September 2012 (UTC)

I think one is sufficient, unless there is to be a section for "eork trick", then probably two. Bubba73 ^{You talkin' to me?} 05:44, 10 September 2012 (UTC)

Ok, it's "stable". ;) Let me know any comments. (And, add the Ruy to that section? Or?) Ok, Ihardlythinkso (talk) 21:53, 10 September 2012 (UTC)

It looks good, although the reason I suggested the Three Knights example instead of this one is that there is a lot of explanation necessary—four different variations plus a footnote covering two other possibilities. For example, it might not be obvious from the footnote why Black is better after 5. Bxf7+?. In the Three Knights example it's much more cut and dried as Black has no reasonable alternatives. It's true that the Three Knights is quite rare, but the goal in this article is to explain the fork, not to get mired in explaining that many peripheral lines.

A section on the fork trick is probably a good idea, but if we wanted two examples I don't think we could use the queen fork in the Open Variation of the Ruy. I think that "fork trick" is usually reserved for a pawn fork to regain a knight used to capture a center pawn. I think it would be great to show that forks can occur in all phases of the game by including an example of a fork in the ending. Bubba73, do you know of any good examples? Quale (talk) 03:20, 11 September 2012 (UTC)

Probably the only endgame example I can think of is K+Q vs. K+R, which I think is usually won by forking the rook and king. Bubba73 ^{You talkin' to me?} 03:58, 11 September 2012 (UTC)

I footnoted the 5.Bxf7+ and 5.0-0 lines to keep the fork trick clear & present, an alternative too would be to eliminate those lines and the four continuation lines, leaving just the fork. Anyway it was a good exercise, discovering some related line omissions along the way, etc. I'm going to remove the section and start over with the Vienna, to see what that brings. Another idea intro'd when developing the Two Knights section was that the section could be about forks in openings, rather than section on fork trick (pawn), so then the Ruy example would have a place. Ok, Ihardlythinkso (talk) 05:39, 11 September 2012 (UTC)

I've looked at Three Knights, and it's clear to me, it's a mistake (tempting for me, but a mistake) to include variations here (either Two Knights or Three Knights) -- that data belongs in the respective openings articles. (For example, 5.Bxf7+ in Two Knights is a "?" move according to ECO [III] leading to −/+ advantage for Black, whereas 4...Bxf2+ in Three Knights leads to no worse off for Black than the 4...Nxe5 mainline does. So, the need to include 5.Bxf7+ line in Two Knights, would seem to be less than need to include 4...Bxf2+ line in Three Knights.) So that means there aren't any more variations to mire in, in Two Knights, than Three Knights, if the lines given here stop short of duplicating coverage in the articles proper (in fact, I discovered more lines in Three Knights, if White is to pull an advantage, than lines in Two Knights, if Black is to get equality; but all that is superflous anyway, since Three Knights article doesn't even try to approach that level of detail). And so in either case, the lines here should end with the pawn forks themselves.

That said, I've re-added the Two Knights example, simplified, for consideration. Ihardlythinkso (talk) 09:05, 11 September 2012 (UTC)

Better? Worse? Okay? Not okay? Ok, Ihardlythinkso (talk) 02:15, 16 September 2012 (UTC)

Simple combination

While we're making modest improvements in this article, I'd like to add a short section at the end showing the fork in a simple combination with another tactical device, such as a pin. I don't think any of our articles give good examples of how tactics are usually applied in practice, and this would end the article with a slightly more complicated example. Pachman provides some good examples, so I think I could borrow one from him. There are many other possible sources too. Again if someone is ambitious enough to take this one themselves, I'm lazy enough to be very happy to let you do it. Quale (talk) 03:30, 11 September 2012 (UTC)

Now that I think of it, enticement is a very common tactical device used with the fork. Frequently a fork is set up by luring a defender to a vulnerable square. The fork trick could be considered an example. Quale (talk) 03:49, 11 September 2012 (UTC)

Fork in ending

I think Bubba's K+Q vs R idea is probably right/good. There already seems to be enough emphasis on forks from knights, but, I did find this do you think it has value here (this is taking right out of the source [Soltis book] w/o any substantive changes) ...

	a	b	c	d	e	f	g	h
8									8
7									7
6									6
5									5
4									4
3									3
2									2
1									1
	a	b	c	d	e	f	g	h

Alekhine vs. Reshevsky, Nottingham 1936

"Now, with 39.Bd4, Black still had to prove he had a win, but Alekhine makes 'another terrible move.' 39. Ba3? e5! Black polishes off the game quickly after this because of the knight forks and the activity of his K. For example, 40.fxe5 Ndxe5+ 41.Nxe5+ Nxe5+ 42.Ke4 Ke6 should be an easy win, e.g. 43.Bc5 Nb4 44.h4 Nf6+ 45.Kd4 (else 55...Kd5) Kf5 scooping up the kingside pawns. 40. Ke3 Ke6 41. Bb2 Kd5 42. Nh4 Nb6! 43. Bc1 Nc4+ 44. Kf2 Nb4! Threatening another N-fork. The key point of Black's maneuver is that 55...Na2 will grease the path of the b-pawn. White will not even get a chance to sacrifice a piece for it if the pawn gets to the sixth rank. The game proceeded 45. Ke2 Na2 46. Bd2 b4 47. fxe5 b3 48. Kd1 Nxe5! There was a last Alekhine trap in 48...b2? 49.Kc2 Nxd2 50.Kxb2 Nb4 51.Kc3 forking the pieces. But Black's move threatened ...Kd5–c4–d3 or ...Ne5–d3–f2+ followed by ...b2. Alekhine tried 49. Ng2 Ke4 50. h4 Nd3 51.Ba5 Nb2+ and resigned because 52.Ke2 Nc4! would either queen the pawn or win the white B."

Ok, Ihardlythinkso (talk) 06:13, 11 September 2012 (UTC)

Forking piece

You're right, I've often heard these described as "forking pieces". — Preceding unsigned comment added by Martin Rattigan (talk • contribs) 12:08, 14 June 2015 (UTC)

Other terms

Has anyone ever seen the terms absolute fork or relative fork used in real chess literature? These were added 100% in good faith, but I don't find the single source provided (https://www.chess-game-strategies.com/chess-fork.html) to be very compelling. Quale (talk) 08:58, 6 December 2020 (UTC)

Graphics showing (not) "forkable" squares

Hi, I made this graphics.

Illustrates combinations of two chess pieces that can be forked with a knight.

It shows combinations of forkable squares. The main insights are: 1. Two enemy pieces have to be on the same color. Most will know this but it will be useful for very new players. 2. There are two cases where being the same color are insufficient for "forkability". These are marked with exclamation marks.

Feel free to incorporate this graphics. Sorry about the color scheme. I know its not the prettiest and doesnt match the standard appearance on Wiki. I made it for myself but thought I might share. — Preceding unsigned comment added by LedZepaholic (talk • contribs) 23:36, 3 January 2021 (UTC)