In the final round, I had Black against Kongpatom Karnjanasirim. Kong had a pretty good Championship debut, losing only to myself and Dickerson in tough games. 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 d6 8.c3 0-0 9.d4 Bg4 10.d5 Na5 11.Bc2 Qc8 12.Nbd2 c6 13.dxc6 Qxc6 14.Nf1 h6 aimed against Bg5. More normal is 14...Nc4 The text was once played by Najdorf back in the 40's. I guess that was in the days before the Najdorf variation was big, although Black's pawn structure here resembles the Najdorf.
15.Ne3 Be6 16.Nf5 Bxf5 17.exf5 I think this position is dynamically equal. White has the two bishops, but Black has two center pawns and a bit more space. Black has to try to mobilize his center while White has to find a way to utilize his bishops. 17...Rfe8 18.a4 Bf8 19.h3 Nc4 20.g4 a double-edge move. It seems logical to attack on the kingside since Black has provided a target at h6, but White's king is a bit loose and if his attack doesn't break through his pawn structure on the kingside will be weakened. 20...Nb6 21.axb5 I wasn't sure that this move was immediately necessary since Black gets counterplay along the a-file. 21...axb5 22.Rxa8 Rxa8 23.g5 hxg5 24.Nxg5 I expected 24.Bxg5 Nbd7 24...Ra1 25.Bb3 25.Qf3 allows Black to mobilize his center with 25...d5. I think the best plan was to eye the b-pawn with 25.Qe2 followed by Bd3 25...Nc4 26.Qe2 Be7 my plan was Bd8-c7 followed by d5, but his next move lets me get in d5 immediately. 27.Kh2 d5 28.f4 e4
Black is much better. The two bishops are impotent and the f5 pawn is a target. 29.Bc2 Nd6 30.Nf3 Nxf5 31.Ne5 Qe8 32.Ng4 Qb8 33.Nxf6+ Bxf6 34.Qg4 g6 35.Rg1 Qb6 36.Be3 Nxe3 37.Qc8+ Kg7 38.Rxa1
38...Nxc2 grabbing material, but the computer gives a faster line 38...Qd6 39.Kg3 Bh4+ 39.Ra8 Qf2+ 40.Kh1 Qf1+ 41.Kh2 Qxf4+ Black mates after 42.Kh1 Qf1+ 43.Kh2 Be5#; 42.Kg2 Ne3+ 43.Kg1 Qf1+ 44.Kh2 Be5#; or 42.Kg1 Qg3+ 43.Kf1 (43.Kh1 Qe1+ 44.Kh2 Be5+ 45.Kg2 Ne3#) 43...Qe1+ 42.Kg2 Ne3+ 43.Kh2 Be5# 0-1
In the 4th round, I had White against Leonard Dickerson. This looked to be the key game in deciding the championship since we were the two highest rated players and were ahead of the rest of the field at this point. 1.d4 d6 2.e4 Nf6 3.Nc3 c6 4.a4 a5 5.g3 Na6 in the 2002 Tennessee Open, he tried 5...Qb6 here 6.Bg2 e5 7.Nge2 Nb4 8.0-0 Be7 9.h3 Be6 10.b3 in the above mentioned game, he got some active play in a similar position with the move Be6-c4, so I decided to prevent it, but White is making a lot of pawn moves instead of developing pieces. 10...Qd7 11.Kh2 h5 12.f4 Qc7 13.Kh1 avoiding tactics such as 13.Be3 h4 14.g4 Bxg4 or 13.Bb2 h4 14.g4 Bxg4 15.hxg4 Nxg4+
13...Bd7 the immediate 13...0-0-0 is better 14.Be3 0-0-0 15.Qd2 exd4 16.Nxd4 d5 17.exd5 Nfxd5 18.Nxd5 Nxd5 19.Bxd5 cxd5 20.Nb5 Bxb5 21.axb5 Bb4 21...Qd7 22.Qc3+ Kb8 23.f5 is very good for White 22.Qf2 22.b6 Qc6 23.Qg2 is about equal, but 22.Qd3 keeping the b-pawn covered is better for White
22...Bc3? 22...Qd7 23.Kh2 (23.f5 Qxb5 24.Bd4 h4 25.g4 Rhe8)23...Qxb5 24.c3 Bd6 25.c4 Qxb3 (25...dxc4 26.bxc4 Qf5 27.Bb6 Bb4 28.Bxd8 Rxd8) is complex. After the game, we spent a considerable amount of time looking at the line 22...d4 23.Bxd4 Rxd4 24.Qxd4 Bc3 25.Qa7 Bxa1 26.Qa8+ Qb8 (26...Kd7 27.Rd1+ Ke7 28.Qxh8 Qxc2 29.Qd8+ Ke6 30.Qd7+ Kf6 31.Rd6#) 27.Qxa5!? (this looks like a draw with accurate play by Black, so White should be content with the pawn up ending after 27.Qxb8+ Kxb8 28.Rxa1) 27...Bd4 (27...Bf6 28.b6) 28.b6 Qd6 29.Qa8+ 23.Bb6 Qd7 it was necessary to cover c5 with 23...Qd6 but White is still better after 24.Ra4 (or 24.Bxd8 Bxa1 25.Bxa5 Bf6) 24...Rde8 25.Bxa5 Bxa5 26.Rxa5 24.Qc5+ Kb8 25.Qxc3covering g3 25...Qxh3+ 26.Kg1 h4 27.Qc7+ 1-0
My second round game against Patterson was postponed, and ended up not being played. In the third round, I had White against Matthew Marsh who was the replacement player for Tsitseklis. Matthew had a rough time in this year's event with some brutal losses, but made up for it in the last round with a nice win over Dickerson, featuring a queen sacrifice. 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 6.e4 g6 7.f4 Qe7 8.Nf3 Bg4 9.h3 9.Be2 and 9.Bb5+ are other possiblities 9...Bxf3 10.Qxf3 Bg7 11.Bd3 0-0 12.0-0 a6 13.a4 Nbd7 14.Be3 Rac8 I prefer either 14...Rfc8 or 14...Ne8 15.Rae1 15.Rfe1 also deserves consideration 15...Rfe8 16.Bf2 Qd8 17.Kh1 Qa5 18.Bh4 c4 19.Bc2 Rc5 20.Bf2 Rcc8
21.Bh4 I decided to repeat moves since the consequences of 21.Bd4 Nxd5 22.Bxg7 Nb4 were difficult to assess. 21...Rc5 22.e5 Nxd5
23.Ne4 This leads to an advantage to White, but even stronger is the forcing 23.Nxd5 Rxd5 24.b4 cxb3 25.Bxb3 and if the rook moves, 26. e6. 23...Rc7 24.Nxd6 Rf8 Better is the immediate 24...Rb8 25.Rd1 Nb4 26.Be1 26.Nxb7? is a mistake because of 26...Rxb7 27.Qxb7 Nc5
26...Rb8? my intention was 26...Qc5 27.Bf2 Qa5 28.Nxb7 now that c5 is covered by the bishop 27.Qc3 Nxe5 28.fxe5 Bxe5 29.Qxb4 Qxb4 30.Bxb4 Bxb2 31.Ne4 Re8 32.Nf6+ Bxf6 33.Rxf6 Re2 34.Rf3 1-0
I got off to a slower start than in years past with a draw with Black against Jason Knight in the first round. 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. c3 Nf6 5. d3 d6 6. b4 Bb6 7. a4 a6 8. O-O O-O 9. Be3 Ba7 10. Nbd2 Ne7 11. Bxa7 Rxa7 12. d4 Ng6 13. Re1 Qe7 14. Qb3 Nf4 15. b5?!
This only helps Black trade his worst place piece, the Ra7. Better is 15. Rad1 Ra8 with slight advantage to White 15... axb5 16. axb5 Rxa1 17. Rxa1 exd4 Completing development with 17... Bg4 is also possible 18. cxd4 Nxe4 19. Re1? White gets some activity with this move, but not enough for a pawn. Better is 19. Qe3 d5 20. Qxf4 Nxd2 21. Bxd5 Nxf3+ 22. Qxf3 with equality 19... Nxd2 20. Rxe7 Nxb3 21. Bxb3 c6 22. bxc6 bxc6 23. Rc7 Bg4 24. Ng5 24. Rxc6 Bxf3 25. gxf3 Ne2+ 26. Kg2 Nxd4 27. Rb6 Nxb3 28. Rxb3 is clearly better for Black.
24... Ne2+ I was too tempted by the prospect of connected passed pawns. Stronger is 24...d5 25. f3 (25. h3 Bh5) 25... Bf5 26. Bd1 f6 27. Nh3 Bxh3 28. gxh3 Rb8 29. Kf2 Rb2+ 30. Ke3 Ng2+ 31. Kd3 Ne1+ 32. Kc3 Rxh2) 25. Kf1 Nxd4 26. Bxf7+ Kh8 27. f3 Bf5 28. Ba2 Bd3+?
My original intention was ... d5 but I couldn't quite calculate the correct move order after 29. Nf7+ Kg8 30. Ne5 the right way is 30...Ra8 (30... Re8 31. Nxc6 Bd3+ 32. Kg1 Re1+ 33. Kf2 Re2+ 34. Kg1 Rxa2 35. Nxd4 is not as good) 31. Nxc6 Bd3+ (31... Rxa2 32. Nxd4; 31... Nxc6? 32. Bxd5+) 32. Ke1 (32. Kg1 Ne2+ 33.Kf2 Rxa2 34. Nb4 Nc3+ 35. Nxa2 Nxa2 36. Ke3 Bc4 37. Kd4) 32... Rxa2 33. Nxd4 Rxg2 with clear advantage to Black. Instead, I decided to reverse the move order, missing a nuance. 29. Kf2 Bg6 a sorry retreat, but 29... d5 30. Ke3 is good for White 30. Ne6 Nxe6 31. Bxe6 Be4 Black even loses after 31... Be8? 32. Rc8 32. Ke3 Bb1 33. Rxc6 Re8 34. Rc8 Black wasn't really threatening to take the bishop because of his weak back rank, so better was 34. Kd4 Rd8 35. Bc4 followed by Kd5 and Rxd6 although it will still be a draw. 34...Rxc8 35. Bxc8 Kg8 36. Kd4 Kf7 37. Bb7 h6 38. h4 White could force a pawn ending with 38. Be4 Ba2 39. Bd5+ interestingly he offers this a few moves later 38... Bc2 39. g3 Bd1 40. Bc6 Ke6 41. Bd5+ Kf6 42. Be4 Bb3 43. Bd5!? Bd1 The White king offsets Black's passed pawn, so 43...Bxd5 44. Kxd5 Ke7 45. h5 Kd7 46. g4 Ke7 will soon be drawn. 1/2-1/2 Jason was looking like a contender after this draw and a win over Marsh in round 2, but a couple of setbacks with Black in the Dragon (0.5/2, which should have been 0/2), set him back.
Before showing my Knoxville City Championship games, I wanted to present my analysis of an interesting endgame from the US Championship. In the sixth round, Michael Casella and Iryna Zenyuk played a game that looks to be important to the theory of the Bayonet Variation of the Kings Indian. 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. b4 Nh5 10. Re1 f5 11. Ng5 Nf6 12. Bf3 c6 13. Bb2 h6 14. Ne6 Bxe6 15. dxe6 fxe4 16. Nxe4 Nxe4 17. Rxe4 d5 18. cxd5 cxd5 19. Rxe5 Bxe5 20. Bxe5 Qb6 21. Bb2 Kh7 22. Qe2 d4 23. h4 Rf6 24. Re1 Qxb4 25. a3 Qd6 26. h5 Raf8 27. Qe4 Nc6 28. hxg6+ Kg7 29. Bc1 Qe7 30. Bxh6+ Kxh6 31. Qh4+ Kxg6 32. Bxc6 bxc6 33. Re5 Rxe6
No comments up to this point, since the players have been following the game Shirov-Radjabov from earlier this year in Linares. The text is Shirov's improvement on 33... Qxe6 34. Rxe6 Rxe6 35. Qg4+ Kf7 36. Qxd4 when Black was unable to coordinate his rooks. 34. Qh5+ Kg7 35. Rg5+ Qxg5 36. Qxg5+ Rg6 37. Qe5+ Kg8 38. Qxd4 Rf7 39. Qd8+ Shirov's analysis continued 39. g3 Rfg7 when he speculated that Black had a fortress. The key point is that if White advances his f-pawn, the exchange of 2 rooks for queen and pawn on g3 leads to a drawn pawn ending. I worked a long time on trying to break down this fortress. While there are plenty of opportunities for Black to go wrong, I did not find a convincing line. However, I believe Casella's move may be a winning improvement. If nothing else, it presents Black with more opportunities to go wrong. 39... Rf8?! This move may deserve a full question mark, but I believe White can still win after the better 39... Kh7 again trying to establish Shirov's fortress. I believe White can achieve the pawn structure f3/g2 instead of f2/g3, which is much more favorable. For example, 40. Qh4+ Kg8 41. Qc4 Kf8 42. Qb4+ Kg8 43. Qb3 Rgf6 44. f3 the difference is that the assesment of the pawn ending after a massive exchange on f3 depends on the position of the Black king. These pawn endings are closely related to those governed by Bahr's rule, which gives an assessment of endings with blockaded rook pawns and an outside passed pawn. Normally, the position with a pawn on g3 (or f3) would be winning. However, the presence of the c6 pawn complicates matters as it costs the white king an extra tempo on his way to capturing the a-pawn. Therefore, one would think that the White g-pawn would need to be one square further back than in the Bahr's rule position (i.e., on g2). However, if the Black king is on the 7th rank, then he will need an extra move to capture the g3 pawn. This sounds complex when described in words, but the following variation should help to clarify things 44... Kh7 45. Kf2 Kh6 46. Qe3+ Kg7 47. Qg5+ Kh7 48. Qg4 Kh6 49. a4 I think this is a zugzwang position, the point is to drive the Black king to an inferior position 49... Kh7 50. g3 now the pawn ending 50... Rxf3+ 51. Qxf3 Rxf3+ 52. Kxf3 wins for White 52... Kg6 53. Ke4 Kg5 54. Kd4 Kg4 55. Kc5 Kxg3 56. Kxc6 Kf4 57. Kb7 a5 58. Kb6 Ke5 59. Kxa5 Kd6 60. Kb6 Kd7 61. Kb7 +- If Black doesn't exchange on f3 then White establishes the pawn structure g3/f4 as he does in the game, which seems to be winning. 40. Qd7 Rf7 41. Qe8+ Kg7 42. g3 Rgf6 43. f4 Kh6 44. Kg2 c5 sitting passively doesn't work now. For example, 44... Kg7 45. Kf3 Kg6 46. Qe5 Kh7 47. Ke4 Kg6 48. Qg5+ Kh7 and White advances 49. f5 since the pawn ending is again hopeless for Black. 45. Kf3 Rf5 45... Rc7 46. Qh8+ Kg6 47. Qg8+ Rg7 48. Qc8 and the c-pawn is lost 46. Ke4 Kg6 47. Qg8+ Kh6 48. a4 R5f6 49. Qc8 49. Qg5+ Kh7 50. Qxc5 is more to the point, now Black gets a bit of activity 49... Re7+ 50. Kf3 Rb6 51. Qxc5 Rb3+ 52. Kg2 Re2+ 52... Rg7 seems to still offer some chances to defend. For example, 53. Qf2 Ra3 and either g3 or a4 falls. 53. Kh3 Ree3 54. Qg5+ Kh7 55. Kh4 Rxg3 56. Qxg3 Rxg3 57. Kxg3
Here is the Bahr's rule position, White wins as long as his outside passed pawn has not advanced beyond the h2-b8 diagonal. Thus, White is winning, but if the f4 pawn was on f5, Black would draw with 57...a5! 57... Kg6 The last trap to set would be 57...a5 58. Kf3 Kg6 59. Ke4 Kf6 hoping for 60. f5? instead of 60. Kd5 58. a5 Kf5 59. Kf3 Kf6 60. Ke4 Ke6 61. a6 Now, with the White pawn already on a5, he would still be winning after 61. f5+ 61...Kf6 62. Kd5 [1:0]
The Knoxville City Championship ended last night with more of a whimper than a bang. I didn't have a game scheduled, so I wasn't present, and apparently not many people were. The two games that were scheduled both were forfeited. This meant that no one could catch my 3.5/4 score, making my final game unnecessary. So for the 7th straight year, I am the Knoxville City Champion.
The usual scheduling problems with the Championship were exacerbated this year by a couple of factors. The Club was meeting on Thursdays this year instead of the usual Wednesday. This meant we lost a week because of Thanksgiving and another week because of the proximity to Christmas. Additionally, Emmanuel Tsitseklis, who had qualified for this year's championship, did not show up the first night and was replaced, and Fheo Patterson had to work the first two weeks. If Tsitseklis and Patterson had been paired together one of those weeks, things might have worked out better, but instead, almost every player had a game to make-up before the first move was even played. I'm actually surprised we got as close to a full schedule as we did. I proposed moving the start of next year's championship a few weeks earlier to avoid the holidays and this seemed to be taken favorably.
As is my custom, I'll be publishing notes to all of my games, starting sometime in the next few days.
Congratulations to 16-year-old GM Hikaru Nakamura, who capped an outstanding year by capturing the US Championship. In an exciting final round, both he and GM Alexander Stripunsky won complex games to boost them a full point ahead of the field. On Sunday, Nakamura swept the rapid tiebreaker to take the title.
Hikaru was one of players I picked as a favorite entering the event. Other players I tabbed had mixed results. GM Goldin was in the thick of things until the end when he lost to Stripunsky in the final round in a game which earned Stripunsky one of the best game prizes. GM Kaidanov finished 3rd on tiebreak, but lost to both of the winners and wasn't a threat to take the title after losing to Nakamura in the 7th round. GM Onischuk got off to a slow start, only even through the first 4 rounds. A solid +3 in the last 5 also placed him in the tie for 3rd. The defending champion, GM Shabalov had an up and down tournament. He was upset in the very first round by Anna Zatonskih, but won 3 straight to get back into the race. Losses in rounds 6 and 8, however left him with nothing to do in the last round except play the spoiler in the women's championship, which he did by winning a nice attacking game against Irina Krush. GM Kamsky showed some rust. He played very solid chess, finishing undefeated, but only managed 2 wins to finish well off the pace.
The two Tennessee players went in different directions after the rest day. Ron Burnett scored 2.5/3 to climb back to an even score. Jake Kleiman unfortunately lost his final 3 games to finish with 2.5 points.
The special $5000 fighting chess award went to GM Fishbein. I haven't looked at his games closely enough yet to say if this award was based more on his play or more on the fact that he was the only player with a positive score who had 8 decisive results. I'm sure the latter factor played heavily into account after the last round fiasco with draws in the previous championship.
Another interesting Kings Indian took place in the third round between former US Women's Champion Irina Krush and Tsagaan Battsetseg 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Qe8 another one of the modern ways of playing the Kings Indian, along with 7... Na6 and 7... exd4 8. Re1 8. dxe5 as played in the 7th round game between Muhammad and Christiansen is the move theory regards as the best way to obtain an advantage. The text has been little seen since the game Quinteros-Bednarski, Wijk aan Zee 1973 8... exd4 9. Nxd4 Nxe4 10. Nd5 The above mentioned game continued 10. Nxe4 Qxe4 11. Nb5 Qe7 12. Bf3 Qd8 and eventually ended in a draw. Since Black is somewhat cramped and behind in development, the text makes sense, avoiding the exchange of knights. 10... Qd8 11. Bf3 11. Nb5 Na6 12. Bf3 appears more accurate. Now Black unleashes a tactical storm. 11... Nxf2 12. Kxf2 Qh4+ 13. Kf1 Bxd4 14. g3 Qh3+ 15. Bg2 Nc6! a shot. White was probably expecting something like 15... Qf5+ 16. Bf4 Nc6 17. Nxc7 Rb8 18. Bxc6 Bb6 19. Qxd6 when Black is still a bit better, but there are many complications.
16. Nf4?? 16. Bxh3 Bxh3+ 17. Ke2 Bg4+ is also a disaster for White, but the surprising 16. Nf6+!? forces Black to sacrifice her queen since the g4 square is now covered. However, after 16... Bxf6 17. Bxh3 Bxh3+ A rather fascinating position arises. Black has only two pieces and two pawns for her queen, but may even stand better since White will have problems untangling her queenside.
18. Kg1 Rfe8 and Black has many ideas such as Bd4 plus Bf5-e4 or Ne5 and Be6 piling up on the c-pawn. It is difficult to find a plan for White. Instead, after the text White's position completely collapses. 16... Qxh2 17. Be3 Bxe3 18. Rxe3 Be6 19. b3 Rae8 20. Qd2 Ne5 21. Qc3 g5 22. Nd3 Bh3 [0:1]
I thought the opening in the 1st round game between GM Boris Gulko and Marcel Martinez was quite interesting. 1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 O-O 5. d4 d6 6. Be2 Na6 7. O-O e5 8. Re1 exd4 The most common move here is 8... c6 which I played against Gulko in the 2003 World Open. 9. Nxd4 Nc5 10. Bf1 Ng4 10... c6 11. Nb3 Qe7 12. f3 Nfd7 13. Be3 is evaluated as clearly better for White by Nunn and Burgess on the basis of the game Furman-Artsukevich, Leningrad 1953. I haven't been able to find that game, but I think the assessment is too optimistic. I was very impressed by Black's play in the game Salman-Sarkar, Philadelphia 2003 13... Ne5 14. Qc2 Be6 15. Nxc5 dxc5 16. b3 f5 17. Rad1 f4 18. Bc1 g5 19. Be2 g4 20. fxg4 Nxg4 21. Bxg4 Bxg4 22. Rd3 Rad8 23. Rxd8 Qxd8 24. h3 Qd4+ 0-1 The retreat Nb3 doesn't feel right to me. Exchanging on c5 gives Black a nice dark-squared grip, but what else is the knight doing there. The setup Gulko employs in this game seems much more natural. 11. f3
11...Ne5 The plausible looking 11... Qh4 was brutally refuted in the game Rodriguez-Rojas, Argentina 1994 12. fxg4 Bxd4+ 13. Qxd4 Qxe1 14. Bh6 Ne6 15. Qf6! Qxa1 16. Nd5 Re8 17. Nxc7 Qc1 18. Bxc1 Nxc7 19. Bh6 Ne6 20. c5 [1:0] My eye was drawn to a similar idea 11... Nxh2 12. Kxh2 Qh4+ 13. Kg1 when again 13... Bxd4+ 14. Qxd4 Qxe1 15. Bh6 Ne6 16. Qf6 wins for White. Black can throw in the move 13...Be5 threatening mate with the idea that 14. f4 blocks the c1-h6 diagonal preventing the move Bh6. Alas, after 14...Bxd4+ 15. Qxd4 Qxe1 16. b4 Ne6 17. Qf6 I don't see a good defense for Black to White's multiple ideas such as Nd5, Bb2, and/or f5+Bh6. A good lesson in what can happen when you part with the Kings Indian bishop too early. 12. Be3 c6 13. Qd2 a5 14. Rad1 Qb6 15. Kh1 a4 16. f4 Ng4 17. Bg1 Qa5 18. h3 Nf6 19. g4 Re8 20. Bg2 Ne6 This doesn't seem to be right, Black has to be very careful in these types of positions or he just loses his d-pawn for nothing. Other ideas are 20...a3, 20...Qb4 and 20...Nfd7. The position after the latter move is interesting if you compare it to a line from the fianchetto variation of the Kings Indian. The following position is from the fianchetto variation and has occurred many times in practice (including a loss by Fischer when he was young).
If we compare that position to the one after 20...Nfd7 we find that White has gotten the moves Qc2-d2, g3-g4, Kg1-h1, and Bf2-g1 for free. On top of all that, the diagram from the fianchetto variation is Black to move, whereas it would be White to move in the present game. It probably isn't your day if you are giving 5 tempi (most of them useful) to a player as strong as Boris Gulko, so it isn't a surprise that this game didn't last much longer. 21. Nc2 Qc7 22. f5 Nc5 23. e5 Nxg4 24. exd6 Qd8 25. Rxe8+ Qxe8 26. hxg4 [1:0]