Quo Valdis Chess Open 2025

Open SwissStandard

63 players participated in this 8-round tournament, held from 06 Jun 2025 to 08 Jun 2025 in Nyeri, Kenya. 6 titled players from 2 federations. Top 10 Elo average was 1986, and top seed was Gong Thon Gong (🇸🇸 SSD, CM, 2253).

Simiyu Jadon (🇰🇪 KEN, FM, 1958) won with 7.5/8, ahead of Peter Majur Manyang (7.0) and Madol Garang Panthou Joh (6.0). Jadon won solo starting round 5.

The biggest upset came in round 6: Lenny Mataiga Shile (1895) beat Gong Thon Gong (CM, 2253), a +358-point gap.

Location

🇰🇪Nyeri, Kenya

Dates

06 Jun 2025 → 08 Jun 2025

Time control

Standard: 90 minutes for the whole game

System

Swiss · 8 rounds

Top seed

🇸🇸CMGong Thon Gong2253

Avg top 10

1,986

Participants

Titled players · 6

FM×2

CM×2

WFM×2

Federations · 2 represented

🇰🇪Kenya×43

🇸🇸South Sudan×4

Top 3

🥇
FMSimiyu Jadon
🇰🇪KEN·1958
7.5pts·2403perf+127.2
🥈
FMPeter Majur Manyang
🇸🇸SSD·2082
7.0pts·2207perf+19.4
🥉
CMMadol Garang Panthou Joh
🇸🇸SSD·2111
6.0pts·2051perf-7.4

How it unfolded

Top 6 · 8 rounds

FM Simiyu Jadon led from R5; +0.5-point edge over the runner-up. Title race converged from 2 co-leaders at R4 to 1 by R5.

Co-leaders

Jadon7.5Manyang7Shile6Gong6Joh6Mwangi5.5

R5–R8 · LEAD HELD

FM Simiyu Jadon held the sole lead from R5 through R8 without losing it.

R5 · HEAD-TO-HEAD · WINNER VS 2ND

FM Simiyu Jadon beat FM Peter Majur Manyang (White).

WIN STREAKS · 3 top finishers

FM Simiyu Jadon 5 wins (R1–R5)FM Peter Majur Manyang 4+3 wins (R1–R4, R6–R8)Lenny Mataiga Shile 3 wins (R4–R6)

Key matchups · top 4

Head-to-head between the four finishers

Player	1	2	3	4
1FMSimiyu Jadon	*	1	—	1
2FMPeter Majur Manyang	0	*	1	—
3Lenny Mataiga Shile	—	0	*	1
4CMGong Thon Gong	0	—	0	*

Grille américaine

#	Player	Elo	Fed	R1	R2	R3	R4	R5	R6	R7	R8	Pts	Bu C1	Bu	SB	Perf	Δ
1	Simiyu JadonFM	1958	KEN	+46B	+9N	+4B	+26N	+2B	=6N	+3B	+7N	7.5	39.0	41.5	38.75	2403	+127.2
2	Peter Majur ManyangFM	2082	SSD	+17N	+10B	+19N	+3B	−1N	+11B	+5N	+8B	7.0	39.5	44.0	36.50	2207	+19.4
3	Madol Garang Panthou JohCM	2111	SSD	+18B	+13N	+5B	−2N	+25B	+9N	−1N	+10B	6.0	40.0	44.5	30.00	2051	-7.4
4	Gong Thon GongCM	2253	SSD	+11N	+14B	−1N	+10B	+16B	−5N	+18B	+9N	6.0	38.0	42.5	29.00	2073	-24.4
5	Shile, Lenny Mataiga	1895	KEN	+41N	+12B	−3N	+36B	+17N	+4B	−2B	+19N	6.0	36.5	39.5	26.50	2109	+42.8
6	Brian Gabriel Mwangi	1928	KEN	−12N	+7B	+46N	+14B	+18N	=1B	−8N	+16B	5.5	37.5	40.0	25.75	1972	+9.8
7	Chumba Allan	1926	KEN	=8B	−6N	+38B	+42N	+39B	+16N	+13B	−1B	5.5	35.0	38.0	22.25	1894	-1.8
8	Kangwana Hosni	1732	KEN	=7N	+15B	+36B	−16N	+48B	+27N	+6B	−2N	5.5	35.0	37.5	23.25	2001	+49.2
9	Ngony, John Thon	1836	KEN	+47N	−1B	+23N	+27B	+21N	−3B	+26N	−4B	5.0	36.5	39.0	19.50	1893	+7.6
10	Nyaga, James Kabui	1842	KEN	+38B	−2N	+29B	−4N	+42B	+41N	+12B	−3N	5.0	34.5	37.5	18.50	1931	+16.6
11	Michuki, Francis	1797	KEN	−4B	+52N	+33B	+20N	+26B	−2N	−16B	+22N	5.0	34.5	36.5	19.00	1900	+13.4
12	Hongo, Victor Machel	1732	KEN	+6B	−5N	−20B	+38N	+50N	+14B	−10N	+26B	5.0	33.5	35.5	20.00	1826	+15.0
13	Chiman Garang Chiman	1853	KEN	+23N	−3B	−34N	+29B	+32N	+21B	−7N	+28B	5.0	32.5	36.5	21.00	1771	-25.2
14	Mongeli, SashaWFM	1864	KEN	+33B	−4N	+22B	−6N	+49B	−12N	+45B	+30N	5.0	32.0	34.5	18.00	1786	-12.0
15	Njoki John Mutuku	1716	KEN	=16B	−8N	+44N	−17B	+37N	=24B	+31N	+27B	5.0	30.5	33.5	19.00	1712	-0.4
16	Okeyo, Steve Austine	1914	KEN	=15N	+34B	+21N	+8B	−4N	−7B	+11N	−6N	4.5	37.0	41.0	21.50	1859	-10.8
17	Wanjiru Chrisphinus	1755	KEN	−2B	+25N	+30B	+15N	−5B	=19N	−20B	+37N	4.5	35.5	39.0	19.25	1752	-0.8
18	James Emanikor	1787	KEN	−3N	+49B	+37N	+19B	−6B	+20N	−4N	=21B	4.5	34.5	37.0	17.25	1898	+16.2
19	Mwabu, Timothy	1882	KEN	+29B	+28N	−2B	−18N	+52N	=17B	+36N	−5B	4.5	33.5	35.5	15.75	1812	-12.8
20	Achiek Kueth Reng	1870	SSD	−34N	+45B	+12N	−11B	+28N	−18B	+17N	=24B	4.5	31.5	34.5	18.75	1723	-27.2
21	Mikuli Lewis Owino	0	KEN	+31N	+47B	−16B	+49N	−9B	−13N	+29B	=18N	4.5	29.5	32.0	15.25	1711	0.0
22	Okemwa Eugene	1697	KEN	−27N	+44B	−14N	=23B	+43N	+48N	+25B	−11B	4.5	29.0	31.5	15.25	1466	-20.6
23	Fantalis Lucy Nduta	1584	KEN	−13B	+40N	−9B	=22N	−24B	+47N	+39B	+46N	4.5	28.5	31.0	14.25	1648	+16.8
24	Onyango Shirlyn Gathoni	1550	KEN	−36N	−26B	=47N	+58B	+23N	=15N	+51B	=20N	4.5	26.0	27.0	13.50	1709	+38.8
25	Githiga John	0	KEN	+61N	−17B	+57N	+43B	−3N	=36B	−22N	+41B	4.5	25.5	25.5	8.75	1666	0.0
26	Witness Dhliwayo	0	KEN	+62B	+24N	+42B	−1B	−11N	+39N	−9B	−12N	4.0	33.5	33.5	11.00	1621	0.0
27	Ndirangu, Joyce NyaruaiWFM	1909	KEN	+22B	−36N	+28B	−9N	+31B	−8B	+44N	−15N	4.0	31.5	34.5	15.50	1623	-45.2
28	Kenneth Koome Kinoti	1690	KEN	+35B	−19B	−27N	+30N	−20B	+61N	+43B	−13N	4.0	29.0	29.0	11.00	1571	-28.4
29	Muchugu, Christian Nderi	1660	KEN	−19N	+32B	−10N	−13N	+57B	+50B	−21N	+52B	4.0	27.0	28.0	9.00	1059	-14.6
30	Leone David	0	KEN	=37N	+55B	−17N	−28B	+47N	=38B	+41N	−14B	4.0	26.0	28.0	11.00	1625	0.0
31	FIDE 554000050	0	—	−21B	+59N	−48B	+53N	−27N	+32B	−15B	+51N	4.0	24.0	25.0	9.00	1013	0.0
32	John Njuguna	0	KEN	+56B	−29N	−35B	+51N	−13B	−31N	+61B	+45N	4.0	23.5	23.5	6.50	1430	0.0
33	Mwega Nkanda	1642	KEN	−14N	+50B	−11N	+46B	F	F	+53N	+44B	4.0	19.5	19.5	9.50	1673	+2.4
34	Waweru Davidson Mugo	1659	KEN	+20B	−16N	+13B	F	F	F	+50N	+54B	4.0	18.0	18.0	13.50	2004	+53.2
35	Waweru Trevor Kipngetich	1539	KEN	−28N	+58B	+32N	F	F	F	+42B	+43N	4.0	15.0	15.0	11.00	1646	+11.6
36	Shikuku Clinton	1817	KEN	+24B	+27B	−8N	−5N	+61B	=25N	−19B	−38N	3.5	32.5	32.5	10.75	1630	-28.6
37	Muturi, Elsie	1411	KEN	=30B	+43N	−18B	−41N	−15B	+40N	+56N	−17B	3.5	27.5	29.0	10.00	939	-10.2
38	Kariuki, Silvia Wahito	1560	KEN	−10N	+57B	−7N	−12B	+59B	=30N	F	+36B	3.5	26.5	27.5	7.50	1636	+5.8
39	FIDE 10852212	0	—	−43B	+53N	+51B	=48N	−7N	−26B	−23N	+56B	3.5	23.5	25.0	6.75	954	0.0
40	Kibui Jackson Githinji	0	KEN	+55N	−23B	−45N	−47B	=46N	−37B	+58N	+49B	3.5	20.5	21.5	6.75	1339	0.0
41	Odongo Bill Clinton	1697	KEN	−5B	−42N	+60N	+37B	+56N	−10B	−30B	−25N	3.0	27.5	28.5	6.00	1494	-41.2
42	Kamanda Ryan	1602	KEN	+51N	+41B	−26N	−7B	−10N	−46B	−35N	+59B	3.0	26.0	27.0	6.00	1508	-24.4
43	FIDE 10897860	0	—	+39N	−37B	+63N	−25N	−22B	+52B	−28N	−35B	3.0	26.0	26.0	5.50	784	0.0
44	FIDE 554000432	0	—	+60N	−22N	−15B	−56B	+58N	+53B	−27B	−33N	3.0	22.0	23.0	4.00	941	0.0
45	Ndegwa Irwin Ndege	1440	KEN	+48N	−20N	+40B	+50B	F	F	−14N	−32B	3.0	21.5	21.5	8.00	1040	-6.4
46	Riungu Kevin	1735	KEN	−1N	+63B	−6B	−33N	=40B	+42N	F	−23B	2.5	30.5	30.5	4.75	1503	-29.6
47	Nthiga Blair Wema	1560	KEN	−9B	−21N	=24B	+40N	−30B	−23B	+55N	F	2.5	28.5	30.5	7.75	1521	-11.2
48	FIDE 554000440	0	—	−45B	+56N	+31N	=39B	−8N	−22B	F	F	2.5	26.5	28.0	7.25	823	0.0
49	FIDE 554000416	0	—	+59N	−18N	+61B	−21B	−14N	=56B	F	−40N	2.5	22.5	22.5	1.75	1025	0.0
50	FIDE 554000394	0	—	F	−33N	+52B	−45N	−12B	−29N	−34B	+61N	2.0	22.0	22.0	2.00	827	0.0
51	FIDE 10897399	0	—	−42B	F	−39N	−32B	+62N	+54B	−24N	−31B	2.0	21.0	21.0	2.00	776	0.0
52	FIDE 554000408	0	—	+58N	−11B	−50N	F	−19B	−43N	+57B	−29N	2.0	20.5	21.5	2.00	980	0.0
53	FIDE 554000114	0	—	F	−39B	+54N	−31B	F	−44N	−33B	+57N	2.0	17.5	17.5	3.00	842	0.0
54	FIDE 554000068	0	—	F	F	−53B	+57N	+60B	−51N	F	−34N	2.0	12.0	12.0	2.00	859	0.0
55	Nathaniel Waithaka	1464	KEN	−40B	−30N	+59B	F	F	F	−47B	+62N	2.0	11.0	11.0	1.00	760	-14.8
56	Stephen Njoroge	0	KEN	−32N	−48B	F	+44N	−41B	=49N	−37B	−39N	1.5	22.0	22.0	4.25	754	0.0
57	FIDE 554000378	0	—	F	−38N	−25B	−54B	−29N	+58B	−52N	−53B	1.0	20.0	21.0	1.00	810	0.0
58	FIDE 554000386	0	—	−52B	−35N	+62B	−24N	−44B	−57N	−40B	F	1.0	18.0	18.0	0.00	745	0.0
59	Ngari Juliet Nyambura	0	KEN	−49B	−31B	−55N	F	−38N	+62B	F	−42N	1.0	17.0	17.0	0.00	742	0.0
60	FIDE 554000122	0	—	−44B	+62N	−41B	F	−54N	F	F	F	1.0	10.0	10.0	0.00	897	0.0
61	FIDE 554000360	0	—	−25B	F	−49N	F	−36N	−28B	−32N	−50B	0.0	22.5	22.5	0.00	954	0.0
62	FIDE 554000424	0	—	−26N	−60B	−58N	F	−51B	−59N	F	−55B	0.0	12.0	12.0	0.00	664	0.0
63	Gikuru Dancan	0	KEN	F	−46N	−43B	F	F	F	F	F	0.0	9.5	9.5	0.00	935	0.0

Key insights

Biggest movers and upsets — the story behind the numbers.

Top rating gainers

1Simiyu JadonFMKEN
+127.2
7.5 pts · #2
2Waweru Davidson MugoKEN
+53.2
4.0 pts · #27
3Kangwana HosniKEN
+49.2
5.5 pts · #8

Top rating losers

1Ndirangu, Joyce NyaruaiWFMKEN
-45.2
4.0 pts · #26
2Odongo Bill ClintonKEN
-41.2
3.0 pts · #37
3Riungu KevinKEN
-29.6
2.5 pts · #32

Biggest upsets

R6+358 Elo gap
Shile, Lenny Mataiga1895 beat CMGong Thon Gong2253
R3+295 Elo gap
FMSimiyu Jadon1958 beat CMGong Thon Gong2253
R8+257 Elo gap
Kariuki, Silvia Wahito1560 beat Shikuku Clinton1817