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deeper_insight 28-Oct-15, 13:49	A bit on skewers... In another post,Jeremy gave some nice examples of a skewer attack game. See the 11th post down in this thread: gameknot.com" Just to make mention for some of the club members and to avoid confusion when I speak of skewers in the future I want to shed some light on this subject. First of all,there are basically two types of Skewers: 1.absolute skewer 2.relative skewer The absolute skewer like in Jeremy's example in the link above is classified as an absolute because it involves an opponents King being in check and the King must move out of check according to the rules of chess and then the player initiating the skewer can proceed to capture another piece in the line of sight of the file,rank or diagonal to that King after the King was forced to move. In a relative skewer,the difference is that it does NOT involve a King but any other pieces whereas the player being "skewered"is actually NOT FORCED to move any of the skewered pieces by the rules of chess.He most likely will move the most valuable piece out of the line of attacking sight in order to avoid the capture of the most valuable piece,but does not necessarily have to do so. Relative skewer example: The black player above is not forced to do anything,but will of course,will logically move his Q.Then white can proceed to capture blacks Rook if he desires. Absolute skewer example: Note the difference,that white if FORCED to move his King by the rules and then black can capture whites Queen by choice. So,I just wanted to give some breakdown in simplified terms to the 2 types of skewers for the lesser rated in this club or those who were not aware of the differences. But something else that is very important is that when I write about skewers,I generally will NOT use the word skewer!Being from the old school,I will use the words...."X-ray"Attack or sometimes I write..."Ex-Ray Attack"(even though,ex-ray is not official like x-ray in the books).Both of these words are actually SYNONYM's for the word "Skewer".I'm mentioning this to avoid any future confusion when I play with these words. So x-ray=skewer
baddeeds 31-Oct-15, 19:57	But, even relative skewers are ugly. Only once did I get an absolute skewer, but I have won a few games with relative skewers in a similar model to what you showed, as black had to give up his R to avoid losing the Q. Now, there something called a reverse skewer and a perfect example is similar to what Joe said, but if we were to reverse the R and Q, so that the R was on c5, and the Q was on b6 yes that is reverse. Actually, an example occurred in a recent annotation by archduke_piccolo. After which, it was lights out for the person that had to deal with the skewer.
hogfysshe 01-Nov-15, 04:29	jkarp... I wonder if that isn't more correctly called a relative pin. Not absolute because the rook CAN be moved. But you wouldn't want to move the rook because the queen could then be captured. glossary of chess terms en.wikipedia.org Pin When a piece cannot move (either legally or advisedly) because doing so would expose a valuable piece, usually the king or queen, to attack. Pins against the king are called absolute because it is then illegal to move the pinned piece. Other pins are called relative pins. Skewer An attack to a valuable piece, compelling it to move to avoid capture and thus exposing a less valuable piece which can then be taken. X-ray 1. An attack upon two pieces in a line, similar to a pin, synonymous with skewer. 2. A tactic where a piece indirectly attacks an enemy piece through another piece. 3. A tactic where a piece indirectly defends a friendly piece through another piece. but it is true that, in a way, pins and skewers are opposites: in one you must (or should) move, in the other you can't (or shouldn't) move.
deeper_insight 01-Nov-15, 04:44	Deleted by deeper_insight on 01-Nov-15, 05:07.
deeper_insight 01-Nov-15, 05:07	Thanks Hogfysshe! I was just about to post the same thing... Joe(Jkarp), You may want to classify the example you gave above as a "reverse skewer"(where the R and Q are reversed,R being on c5 and Q being on b6)but that would only be labelled under...chess"slang"only. Technically,you are incorrect.I must say this,so that the club readers do not get confused.There is really no "reverse skewer"by definition anywhere,including Google.Check one or both of my sources in this club.Here is just one: en.wikipedia.org) Make sure you click on.."did you mean skewer chess".Sometimes my link transfer does not work properly. Confusion sometimes arrives,because as Wiki mentions it...."A skewer is sometimes described as a "reverse pin"; the difference is that in a skewer, the more valuable piece is in front of the piece of lesser value. So a reverse pin is NOT a reverse skewer.Skewers(x-ray attacks) and pins are similar,but different by definition. What you have there in your example with the Q and R reversed is simply a "relative pin" then on blacks Rook,not his Queen.Yes,the pieces are reversed,but since the King was not forced to move,its simply an example of a "relative pin"since the more valuable piece is NOT in front. It gets a bit confusing,with pins,absolute pins,relative pins,absolute skewers,relative skewers,partial pins and situational pins ect.But keep in mind that skewers(x-rays) and pins by definition are two different breeds of animals! Check this wiki pin example below in the very first diagram and you will see a similar example of what you(jkarp)illustrated with reversing the pieces above.That first diagram gives both a relative pin and an absolute pin.Notice again,it is not classified as a skewer,reverse skewer or x-ray attack. en.wikipedia.org) Make sure you click on "pin chess",sometimes my link transfer does not work properly. Now,if archduke_piccolo called it a reverse skewer(and I did not check his annotation),you may want to correct him as well.He can use any kind of "chess slang"he wants..(I do it too)with my colorful words,but it reality,there is no...."reverse skewer"by true definition. Just some FYI for those still learning the chess words and their definitions. TA
teardrop34 01-Nov-15, 06:49	I've heard both terms x-ray and skewer used interchangeably from my old high school coach. But have to agree with what was said about the differences between pins and skewers. There are between 11 and 13 tactical motifs found in a game of chess. Decoy, interception, forks, clearance sacs, pins, skewers, etc. It pays to know these motifs and employ them during play. Note that pins and skewers are listed separately in this list because they aren't the same conceptually. For those interested, the very best book I have found for this area of tactical study is listed here: www.amazon.com. Any edition of this book is fine to get, and I have the 3rd (maybe 4th as well, not positive) in my own collection.
deeper_insight 01-Nov-15, 09:06	Yes,those are some of the best books for study in the tactical conceptions as you noted teardrop34.I'm sure Shamash can list a few more.I have not heard from him in a while,however.I do not have that book out of my vast collection,but I have read through it at the club.The cost is prohibited for most,but worth it.Perhaps older used editions from Amazon or other sources can cut the cost in half.$54.95 is a premium indeed,however.I have not done a complete research to see if an older edition can be purchased for cheap.But with patience and in a few months,I would not doubt that even the 5th edition will become cheaper to buy. Thanks for your input!
baddeeds 01-Nov-15, 10:29	I was wrong when I said that he called it reverse skewers. And, I found the annotation. What ION said was, "and submit to the skewer in reply. So, I said, Now, I have trouble understanding what you mean because this isn't a skewer. Do you mean that white should allow a skewer? His response was, @jkarp: It is a skewer. The bishop attacks the rook, which, forced to move away, uncovers the bishop's attack on the unprotected a-pawn on the same diagonal. It is the reverse - antithesis if you like - of a pin. Bear in mind, too, that the rook can not drop back to d3 to protect the a-pawn on account of his own intervening pawn at d5! There is a bit of a refinement to this 'skewer' as 46.Ra6 would be met by 46...Bxd5ch.
baddeeds 01-Nov-15, 10:32	And, this was the position that he was alluding to.
baddeeds 01-Nov-15, 10:35	In addition, the comments and position happened in this annotation. gameknot.com
teardrop34 01-Nov-15, 10:38	Pin or Skewer? Here's an interesting position to evaluate. Is this just a pin? Or is it a skewer?
hogfysshe 01-Nov-15, 14:28	that's probably a skewer based on black's likely play. the R on e5 is more mobile and influences more squares than the one on h8. if e5 moves away, you have a good B for a momentarily only fair R (minus 2 or less for black). if treated as a pin, black can not defend the better rook (minus 5). ???
redfoxrising 01-Nov-15, 16:01	white moved I took the rook. Blacks turn...
hogfysshe 01-Nov-15, 16:15	well... if black had the move that resulted in the position shown, I hope it was a good one. because if it is white's move, black is losing both rooks. my response above assumes it is black's move. good for discussion either way.
baddeeds 01-Nov-15, 17:19	Impossible for me to state as a fact, but I think it's a relative skewer, in this position. It's similar to what TA showed at the intro of this thread.
teardrop34 01-Nov-15, 20:31	My apologies... This theoretical position was made from white's point of view, but it is black to move. I posted this because sometimes, situations can be confusing to decipher based on pure merit. But credit to all who correctly said it's a skewer. Black's d5 rook is clearly the more valuable piece at this stage of the game. I wouldn't go as far as hogfysshe is saying the h8 rook is worth only 2 points, but his point is valid. One rook is clearly stronger than the other, and black must move the d5 rook to avoid severe damage to this position.
hogfysshe 02-Nov-15, 04:53	I wasn't saying the ROOK was worth 2 points. I was pointing out that by picking up the bishop, a 3-ish point value piece, your net is minus 2 whereas there is no recapture after losing the other rook yielding minus 5. for that simplified calculation, I was treating both rooks as having their standard full value of 5 (even though their relative values at the moment are not equal).

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