33th iChess Cup

Open SwissStandard

67 players participated in this 6-round tournament, held from 13 Jul 2025 to 20 Jul 2025 in Seoul, South Korea. 3 federations represented. Top 10 Elo average was 1670, and top seed was Jaehyun Sung (🇰🇷 KOR, 1748).

Jaehyun Sung (🇰🇷 KOR, 1748) won with 5.5/6, ahead of Junhyeon Chung (5.5) and Sunwoong Moon (5.0). Sung shared the lead from round 1, winning on tie-break.

The biggest upset came in round 1: Moonso Kim (1446) beat Jinwoo Lee (1698), a +252-point gap.

Location

🇰🇷Seoul, South Korea

Dates

13 Jul 2025 → 20 Jul 2025

Time control

Standard: 60 minutes for game

System

Swiss · 6 rounds

Top seed

🇰🇷Jaehyun Sung1748

Avg top 10

1,670

Participants

Federations · 3 represented

🇰🇷South Korea×57

🇬🇺Guam×1

🇦🇹Austria×1

Top 3

🥇
Jaehyun Sung
🇰🇷KOR·1748
5.5pts·1975perf+23.8
🥈
Junhyeon Chung
🇰🇷KOR·1631
5.5pts·1982perf+84.8
🥉
Sunwoong Moon
🇰🇷KOR·1675
5.0pts·1823perf+41.6

How it unfolded

Top 6 · 6 rounds

Tight race until R6; 2 players tied at 5.5/6, decided on Buchholz. Title race narrowed from 3 co-leaders at R4 to 2 at the finish.

Co-leaders

Chung5.5Sung5.5Moon5Kim5Oh4.5You4

R6 · TIEBREAK CLUSTER

2 players finish on 5.5/6. Sung takes the title on Buchholz Cut1 (22.0).

R6 · HEAD-TO-HEAD · WINNER VS 2ND

Junhyeon Chung drew with Jaehyun Sung (White).

WIN STREAKS · 3 top finishers

Junhyeon Chung 5 wins (R1–R5)Jaehyun Sung 5 wins (R1–R5)Sunwoong Moon 4 wins (R1–R4)

Key matchups · top 4

Head-to-head between the four finishers

Player	1	2	3	4
1Junhyeon Chung	*	½	—	1
2Jaehyun Sung	½	*	1	—
3Sunwoong Moon	—	0	*	—
4Hajoon Kim	0	—	—	*

Grille américaine

#	Player	Elo	Fed	R1	R2	R3	R4	R5	R6	Pts	Bu C1	Bu	SB	Perf	Δ
1	Sung, Jaehyun	1748	KOR	+15B	+13N	+5B	+29N	+3B	=2N	5.5	22.0	25.0	22.25	1975	+23.8
2	Chung, Junhyeon	1631	KOR	+11B	+20N	+21B	+4N	+8B	=1B	5.5	21.5	24.5	21.75	1982	+84.8
3	Moon, Sunwoong	1675	KOR	+34B	+58N	+9B	+7N	−1N	+6B	5.0	20.0	21.0	15.50	1823	+41.6
4	Kim, Hajoon	1682	KOR	+28N	+19B	+6N	−2B	+21N	+22B	5.0	18.5	21.5	16.00	1820	+39.6
5	Oh, Jaemin	1559	KOR	+33B	+32N	−1N	=19B	+27N	+7B	4.5	18.0	20.5	13.50	1672	+36.0
6	Joo, Eram	1552	KOR	+12B	+65N	−4B	+13N	+14B	−3N	4.0	21.0	21.0	11.00	1642	+20.0
7	Chung, Inho	1494	KOR	+54B	+10N	+22B	−3B	+9N	−5N	4.0	20.5	21.5	12.00	1671	+50.0
8	Shin, Yisoo	1620	KOR	+27N	−46B	+11N	+23B	−2N	+24B	4.0	18.5	20.5	13.00	1566	-14.0
9	Kim, Sunyong	1554	KOR	+43N	+30B	−3N	+26B	−7B	+20N	4.0	18.0	20.0	11.00	1525	-2.8
10	You, Eunsung	1663	KOR	+57N	−7B	+32N	=14N	+19B	=16B	4.0	16.5	17.5	10.00	1671	+7.2
11	Son, Haseong	1412	KOR	−2N	+62B	−8B	+66N	+23N	+21B	4.0	16.5	16.5	7.00	1581	+35.2
12	Choe, Matthew Hajoon	0	KOR	−6N	+35B	−13B	+48N	+26N	+25B	4.0	16.0	18.0	10.50	1562	0.0
13	Ra, Jayden Sanghyuk	1517	KOR	+37N	−1B	+12N	−6B	+53N	=14N	3.5	19.5	20.5	9.25	1394	-16.8
14	Pollak, Tony	1705	AUT	+50N	=25B	+46N	=10B	−6N	=13B	3.5	16.5	18.5	9.25	1583	-35.2
15	Jeon, Sehyun	1451	KOR	−1N	=39B	+37N	−24B	+33N	+35B	3.5	16.0	18.0	8.50	1703	+24.8
16	Lee, Jinwoo	1698	KOR	−49B	−33N	+43B	+39N	+28B	=10N	3.5	13.5	15.5	9.00	1513	-27.6
17	Kim, Jio	1413	KOR	−29B	−54N	=42B	+40B	+52N	+36N	3.5	11.5	12.5	7.50	1669	+41.2
18	Seo, Yerin	1543	KOR	+39B	−53N	+61B	−20N	=32B	+34N	3.5	11.0	12.0	6.75	1448	-14.8
19	Oshiro, Souta	1516	KOR	+45B	−4N	+65B	=5N	−10N	=27B	3.0	18.5	18.5	5.75	1382	-26.4
20	Oh, Yechan	1489	KOR	+66N	−2B	+41N	+18B	−22N	−9B	3.0	18.0	18.0	5.50	1384	-19.2
21	Kim, Taeu	1543	KOR	+60N	+40B	−2N	+53B	−4B	−11N	3.0	17.5	18.5	4.00	772	-56.0
22	Han, Dohoon	1603	KOR	+59N	+26B	−7N	F	+20B	−4N	3.0	17.0	18.0	7.00	1526	-15.6
23	Hwang, Noel	1532	KOR	−30N	+24B	+59N	−8N	−11B	+40B	3.0	16.0	17.0	6.00	717	-40.4
24	Choi, Sihwan	0	KOR	=38B	−23N	+64B	+15N	=25B	−8N	3.0	16.0	16.5	6.75	1458	0.0
25	Choi, Juneho	1518	KOR	+44B	=14N	−38B	+33B	=24N	−12N	3.0	15.5	17.5	7.75	1429	-9.6
26	Shin, Seojun	1472	KOR	+55B	−22N	+45B	−9N	−12B	+32N	3.0	15.5	16.5	5.50	1397	-10.8
27	Yim, Jeongbeen	1408	KOR	−8B	=64N	+54B	+36N	−5B	=19N	3.0	15.0	15.5	5.25	1455	+2.4
28	Lee, Seoha	1444	KOR	−4B	−44N	+56B	+45N	−16N	+41B	3.0	14.5	15.5	5.00	886	-15.6
29	Kim, Junesun	1637	GUM	+17N	+51B	+47N	−1B	F	F	3.0	13.0	13.0	7.50	1767	+26.0
30	Jeong, Hyeonwoo	0	KOR	+23B	−9N	F	−35B	+42N	+55B	3.0	12.5	13.5	6.00	1448	0.0
31	Yun, Wooseok	1605	KOR	+61B	+49N	+53B	F	F	F	3.0	4.0	4.0	4.00	2245	+11.6
32	Kim, Hyunwoo B	1438	KOR	+35N	−5B	−10B	+44N	=18N	−26B	2.5	17.5	19.5	6.25	1420	-3.6
33	Cho, Hayoon	0	KOR	−5N	+16B	=36B	−25N	−15B	+53N	2.5	17.0	18.0	5.75	1392	0.0
34	Han, Wontae	1439	KOR	−3N	=37B	=39N	+41B	=35N	−18B	2.5	15.5	17.5	5.50	1350	-11.6
35	Lee, Chanjoo	1643	KOR	−32B	−12N	+60B	+30N	=34B	−15N	2.5	15.5	16.5	5.25	1164	-73.6
36	An, Seunggi	1518	KOR	−40N	+43B	=33N	−27B	+55N	−17B	2.5	13.0	14.0	4.25	626	-48.8
37	Lim, Seonghyeon	0	KOR	−13B	=34N	−15B	=42N	+65B	=?N	2.5	11.5	11.5	2.25	1271	0.0
38	Bae, Jaemin	1548	KOR	=24N	+41B	+25N	F	F	F	2.5	8.0	8.0	6.50	2322	+19.2
39	Hwang, Jiu	0	KOR	−18N	=15N	=34B	−16B	−41N	+66B	2.0	15.0	15.0	3.00	1337	0.0
40	Lee, Seungjun	0	KOR	+36B	−21N	−?B	−17N	+43B	−23N	2.0	14.0	14.0	4.50	1255	0.0
41	Park, Sejin A	0	KOR	+?B	−38N	−20B	−34N	+39B	−28N	2.0	13.0	13.0	2.00	1238	0.0
42	FIDE 13234994	0	—	−46N	−59B	=17N	=37B	−30B	+63N	2.0	12.0	13.0	4.00	1246	0.0
43	Cho, Jungbin	0	KOR	−9B	−36N	−16N	+?B	−40N	+?B	2.0	12.0	12.0	0.00	780	0.0
44	Lim, Chanhee	0	KOR	−25N	+28B	−51N	−32B	−?N	+?B	2.0	10.5	10.5	3.00	1253	0.0
45	Moon, Changjun	0	KOR	−19N	+57B	−26N	−28B	−?N	+65B	2.0	10.0	10.0	1.00	1274	0.0
46	Maeng, Chihyun	1483	KOR	+42B	+8N	−14B	F	F	F	2.0	9.5	9.5	6.00	1663	+20.4
47	Jeong, Yoojin	1519	KOR	+56B	+48N	−29B	F	F	F	2.0	9.0	9.0	3.00	842	-13.2
48	Yun, Yejoon	0	KOR	F	−47B	−50N	−12B	+57N	+?B	2.0	9.0	9.0	1.00	1346	0.0
49	Kim, Moonso	1446	KOR	+16N	−31B	+55N	F	F	F	2.0	7.5	7.5	4.50	1652	+20.8
50	Jin, Soohyeon	1447	KOR	−14B	+56N	+48B	F	F	F	2.0	6.5	6.5	3.00	904	-7.2
51	Choi, Jungwoon	1493	KOR	+64B	−29N	+44B	F	F	F	2.0	5.5	5.5	2.50	842	-18.8
52	Park, Sihun	1483	KOR	F	F	F	+60N	−17B	+56N	2.0	5.5	5.5	2.00	610	-24.4
53	Shin, Yijoon	0	KOR	F	+18B	−31N	−21N	−13B	−33B	1.0	15.5	15.5	3.50	1360	0.0
54	FIDE 13231049	0	—	−7N	+17B	−27N	F	F	F	1.0	10.5	10.5	3.50	1321	0.0
55	Suh, Hannah	0	KOR	−26N	F	−49B	+65N	−36B	−30N	1.0	10.5	10.5	0.00	671	0.0
56	Kim, Howon	0	KOR	−47N	−50B	−28N	+57B	−?N	−52B	1.0	10.0	10.0	1.00	1229	0.0
57	Jang, Seyong	1439	KOR	−10B	−45N	−62B	−56N	−48B	+67B	1.0	10.0	10.0	0.00	853	-9.6
58	Lee, Donghwa	1496	KOR	+62N	−3B	F	F	F	F	1.0	9.0	9.0	1.00	872	-12.8
59	An, Teaha	0	KOR	−22B	+42N	−23B	F	F	F	1.0	8.0	8.0	2.00	760	0.0
60	FIDE 13234978	0	—	−21B	−?N	−35N	−52B	−?B	+?N	1.0	7.5	7.5	0.00	747	0.0
61	Kim, Yeonseo	1402	KOR	−31N	+66B	−18N	F	F	F	1.0	6.5	6.5	0.00	772	0.0
62	FIDE 13223488	0	—	−58B	−11N	+57N	F	F	F	1.0	6.0	6.0	1.00	1342	0.0
63	FIDE 13234943	0	—	F	F	F	−?B	+?N	−42B	1.0	2.0	2.0	0.00	655	0.0
64	Park, Seojin A	0	KOR	−51N	=27B	−24N	F	F	F	0.5	8.0	8.0	1.50	1337	0.0
65	FIDE 13234986	0	—	F	−6B	−19N	−55B	−37N	−45N	0.0	12.5	12.5	0.00	731	0.0
66	FIDE 13235001	0	—	−20B	−61N	F	−11B	−?N	−39N	0.0	10.0	10.0	0.00	645	0.0
67	FIDE 13230999	0	—	F	F	F	−?B	−?B	−57N	0.0	1.0	1.0	0.00	651	0.0

Key insights

Biggest movers and upsets — the story behind the numbers.

Top rating gainers

1Chung, JunhyeonKOR
+84.8
5.5 pts · #1
2Chung, InhoKOR
+50.0
4.0 pts · #8
3Moon, SunwoongKOR
+41.6
5.0 pts · #3

Top rating losers

1Lee, ChanjooKOR
-73.6
2.5 pts · #48
2Kim, TaeuKOR
-56.0
3.0 pts · #66
3An, SeunggiKOR
-48.8
2.5 pts · #63

Biggest upsets

R1+252 Elo gap
Kim, Moonso1446 beat Lee, Jinwoo1698
R1+205 Elo gap
Kim, Hyunwoo B1438 beat Lee, Chanjoo1643
R6+192 Elo gap
Jeon, Sehyun1451 beat Lee, Chanjoo1643