Susan Polgar: ZwischenzugAs you probably already know, the German word “zwischenzug” stands for intermediate move or in-between move. This important topic, however, is often forgotten in many books on chess tactics. I found over the years that even good players simply “forget” about “zwischenzug” a lot more frequently than they do about other types of tactics such as forks, pins, or discoveries etc. Let’s first see a couple of simple examples from my own experience. Rodriguez D. : Polgar S. Tunja 1989 fine for Black. However, Black has a problem. The Bishop on b4 is on an unprotected square which enables White to win a Pawn. Polgar S. : Cuijpers Wijk aan Zee Wijk 1986 XIIIIIIIIY 9r+-wq-trk+0 9zpp+n+pzp-0 9-+p+psnp+0 9+-+p+-+-0 9-vlPzP-+-+0 9+-sN-zPN+-0 9PzP-vLQzPPzP0 9tR-+-+RmK-0 xiiiiiiiiy How can White win a pawn? 11.Sd5! Now if 11...Ld2 then 12.Sf6 - intermediate check. 11...Sd5 12.cd5 Ld2. Now comes another intermediate move. 13.de6! La5. 13...Le3 14.De3 Black is down a pawn too. 14.ed7 Lc7 15.b4 Dd7 16.Tab1 White is up a Pawn and I won this game. Now let’s see some examples from other players. Tiviakov : Georgadze G. Gausdal 1992 XIIIIIIIIY 9r+-+kvl-tr0 9zpp+-+pzpp0 9-+N+psn-+0 9wq-+-+-+-0 9-+-zP-+-+0 9+-sN-+-+P0 9PzP-+lzPP+0 9tR-vLQ+RmK-0 xiiiiiiiiy This game is from the World Junior Championship. My opponent's last move was S(c6), assuming that I would either respond with the natural bc6 or Ld1. However, he was up for an unpleasant surprise as I chose neither. I went with the intermediate move 12...Dc3! instead. This wins a piece! 13.De2 Or 13.bc3 Ld1 14.Td1 bc6. 13...Dc6 and I won a little later. In the next example, everything seems to be XIIIIIIIIY 9-+-tr-+-mk0 9+p+-+p+p0 9p+p+lwq-+0 9+-+-+N+-0 9PzP-+PwQ-zP0 9+-vlL+-+-0 9-+-+-zPP+0 9+-tR-+-mK-0 xiiiiiiiiy 1 FIDE SURVEYS – SUSAN POLGAR Dd2 3.Ta3 Kf7 22.Lc4 Lg8 7.Ta7 with an easy win for White. All he needs to play is e6-e5 and then Black's only real bad However.Can Black win a piece here by capturing with 1...Sb5! Sb5 This is forced.Kc7 A great performance by the Alekhine! 1:0...De1 Ld3 Here White tried his last chance.De7 Kg6 11.Td3 In hopes for perpetual checks .Ta8 and 8. the b5 pawn was taboo because of the fork (with Lc6).. 4. 17..Kd4 Le8 Black has no choice but to sit and watch how White improves his position move by move... Therefore.Ke3 Le8 12.. 3.Lb5.Td3? Then. threatening to fork with Sd7.ef6 Lf4.. FIDE SURVEYS – SUSAN POLGAR 2 . White is up a pawn.Dg5 Ke6 True.h5 Kd8 20. then 13. The rest was is pure technique. as after the immediate capture on d3. 22..Tb8 If 3.Sc5! This is the second intermediate move.Kc5 Tb8 19..e5 Is White still saved? Not quite! 2....Ld2! 3.Ke7 23. 2.Td8 Td8 3.f3 Kg3 15.Dg7 Kf4 16.De6 Kg5 12.Tb6 wins. 2. but finally Black ran out of them.Ta1 Sc8 7..De7 Kf5 13. 8. 4.Ld7 13. 12..fe5 10.e5.Ta6! This move indirectly protects the b5 pawn.De6 Kg7 10..Tb6 Naturally.files.f4 Lf7 9.ef5 Td3 Black is already free to escape with the King via g7..e6 fe6 6. there were many checks.Tc3 Dd4 and the pin is deadly.Kc6 Kd8 24.Tc8.. using Black’s back rank weakness.Df7 Kg4 14.h4 Ld7 15..Dh6 Ke5 17.Le2 Tb8 16. White has a hidden trap with 2. 18.Le4 Now Black is helpless.. 9. 14.fe5 Tb6 11.Sd7 Kd7 17.Db8..Td3 Ke7 25. 5.Le6.Lc6 Ke7 21..Tc3!.. followed by 7...Td2..Dd3 8.e5 8.Sd6 6. Black would lose the a7 pawn.Kd2 Sb7 6.Dh4 4... 7. 1. it is White's turn and Alekhine found a nice way to make use of the temporary lack of coordination between the Black pieces. 0:1 Alekhine : Bogoljubow Germany (m/5) 1929 XIIIIIIIIY 9-tr-trnmk-+0 9zpp+-+-zpl0 9-+-+pzp-zp0 9sN-+-+-+-0 9PzP-snP+-+0 9+-sN-+P+-0 9-+-+-mKPzP0 9+-tRR+L+-0 xiiiiiiiiy After a difficult start.Lf3! This move stops any plan of counterplay to activating the Black Rook through b7-c7.. No. if 2. 7.De5 Kg8 9. Soon all of the Black pieces will become paralyzed and the White King can freely enter the Black camp.or f. retreat the Rook to d8. Either the White King will enter to c6 or the Rook through the d.Lf5 Now after 2. Otherwise..ab5! As an end result of the combination. If now 12.Ke7 5.Ke3 Sbd6 5.Sb7! The first intermediate move! 3. then 4. Here are the rest of the moves of the game: 5. Black is close to getting out of his troubles. it is very important to first include the trade with 1. it gives Black the upper hand..Kh1 Df1.Te5 Df7! and again the same idea! 0:1.ef5 And White won. a Bishop. 2. 4.. Black responded with the unexpected: 2. 17.Simagin : Beilin Vilnius 1946 XIIIIIIIIY 9r+-+-trk+0 9+N+-+qzp-0 9p+-+Rsnpzp0 9+p+-+-+-0 9-+-zP-+-+0 9+Q+-+-+-0 9PzP-+-zPPzP0 9+-tR-+-mK-0 xiiiiiiiiy In the position above.Lf3. 1.Td7! Dd7 17. His opponent decided not to recapture right away. 18.Dc5? White overlooked (or underestimated) that Black has another option than the natural recapture on c5.Tb8 Now the Rook enters to the second rank which is very strong. due to the discovery threats in the air.Df5 Or 17. Remarkably. and a Knight for the White Queen and pawn. This in itself isn't necessarily a decisive material advantage. 1:0..Tc5 Tad8 4.Sh6 Lh6 19.Db7?! This only makes life easier for Black..Dd5 Df2 3.g6 18. White’s last move was Sb7. Arakhamia : Spassky Roquebrune 1998 XIIIIIIIIY 9-+-tr-+k+0 9+p+-+-zp-0 9-zpn+-tr-zp0 9+-wqp+-+-0 9-+p+lzPL+0 9zP-zP-wQNzP-0 9-zP-+-+-zP0 9+-+RtR-mK-0 xiiiiiiiiy Here the ex-world Champion played 1.. Balashov : Biyiasas Manila 1976 the pin (on the d-file).Db7 3.Db6 Lg4 4.. but combined with the weaknesses around the White King.Ld1!! Now Black will have a Rook... The Knight on b7 is now indirectly protected.. but to first exchange the Queens with 2.. It turned out to be a mistake as White has another and better option than the immediate recapture on c1: 16. Black has a way to still win a piece.Te2 The Knight (on d5) couldn’t be captured because of the back rank problem: 2.Sd5! This powerful intermediate move wins the game! 2. 3.Dg4 and Black either loses his Queen or gets checkmated. especially because XIIIIIIIIY 9r+-wq-trk+0 9+pzpl+pzp-0 9p+n+-+-zp0 9+-+-zpN+-0 9-+-+P+-+0 9+LzP-+Q+-0 9PzP-+-zPPzP0 9tR-vlR+-mK-0 xiiiiiiiiy Black with his last move (Lc1) was hoping to simply trade Bishops before getting out of FIDE SURVEYS – SUSAN POLGAR 3 ....Dd7.. White is a pawn up. Ta1 2.. However.Df7 and Black resigned the checkmate is unavoidable.both the f.Lg6 Kg8 7.Le6! This is a pretty move using the fact that Black's Bishop is pinned..Kf2 De5 And now 6.Ld3!! first (instead of White moving his King out of the check) changes the whole picture. XIIIIIIIIY 9-+-+-+k+0 9tr-sn-wq-+p0 9-+-+l+-vL0 9+p+-wQL+-0 9-+-+-tR-+0 9+-zp-zP-+-0 9-+-+-+PzP0 9+-+-+-mK-0 xiiiiiiiiy Black’s position looks scary with the King being all exposed. 1:0 FIDE SURVEYS – SUSAN POLGAR 4 . However. 3..Kf2 Tf1 3.a5 Tg2 8..Kf1 Lc4 and winning White's Queen...Le8 Kg8 6.Dh7 checkmate.Ld3 5. 1963 XIIIIIIIIY 9-+-+-+k+0 9+-wql+p+-0 9p+-zp-+pzp0 9+pzpPvl-+-0 9-+-zp-sN-zP0 9+-+P+-zPL0 9PzPP+QzP-mK0 9+-+-+-+-0 xiiiiiiiiy Here Black played 1..Df7 Kh8 8.fe6 4.Tf8# checkmate is possible.. White resigned..Df6 Kh7 6. 2. 5.a4 Lh3 7.De7! This pin and the entrance to the seventh rank is very powerful. 0:1.. Yet. Hromadka : Prokop Prague 1926 Boze : Dennik Corr. the unexpected: 4.Lf4? with hopes to ruin White's pawn structure.Dc7 Tb2 6. 1:0..pawns of White's have advanced already. 5.Lc1 3. 5.Dc8 After 3.. 4..Kh1 Ta2 Now the a-pawn is lost too.Kh8 would only shorten the end by two moves.and g. Black forget that White doesn’t have to recapture but has a better move: 2. 4.. it seemed that Black is getting out of trouble with the following combination: 1.Lf7 Kg7 4.de6 White's passed pawn is unstoppable.