Weekendtoernooi Groninger Combinatie NOSBO PK 2026

SwissStandard

93 players participated in this 7-round tournament, held from 14 May 2026 to 17 May 2026 in Groningen, Netherlands. 5 titled players from 7 federations. Top 10 Elo average was 2214, and top seed was Mees Van Osch (🇳🇱 NED, FM, 2342).

Milan Mostertman (🇳🇱 NED, FM, 2258) won with 6.0/7, ahead of Nanne Van Foreest (6.0) and Leandro Slagboom (5.5). Mostertman won on tie-break after catching the field in the final round.

The biggest upset came in round 7: Nanne Van Foreest (1965) beat Leandro Slagboom (FM, 2334), a +369-point gap.

Location

🇳🇱Groningen, Netherlands

Dates

14 May 2026 → 17 May 2026

Time control

Standard: 90 minutes with 30 second increment from move 1

System

Swiss · 7 rounds

Top seed

🇳🇱FMMees Van Osch2342

Avg top 10

2,214

Participants

Titled players · 5

IM×1

FM×4

Federations · 7 represented

🇳🇱Netherlands×78

🇩🇪Germany×7

🇪🇸Spain×1

🇬🇧England×1

🇵🇹Portugal×1

🇮🇳India×1

🇬🇷Greece×1

Top 3

🥇
FMMilan Mostertman
🇳🇱NED·2258
6.0pts·2392perf+21.0
🥈
Nanne Van Foreest
🇳🇱NED·1965
6.0pts·2401perf+70.8
🥉
FMLeandro Slagboom
🇳🇱NED·2334
5.5pts·2307perf-1.6

How it unfolded

Top 6 · 7 rounds

Tight race until R7; 2 players tied at 6.0/7, decided on Buchholz.

Co-leaders

Van Foreest6Mostertman6Slagboom5.5Koukas5.5Margarido5Baarspul5— ex-leaders:De Roverled R4, #16

R6 · LEADER CHANGE17 May

FM Leandro Slagboom takes the sole lead (5.5/6).

R7 · TIEBREAK CLUSTER

2 players finish on 6.0/7. Mostertman takes the title on Buchholz Cut1 (29.0).

WIN STREAKS · 3 top finishers

Nanne Van Foreest 3 wins (R5–R7)FM Milan Mostertman 3 wins (R1–R3)FM Leandro Slagboom 3 wins (R1–R3)

Key matchups · top 4

Head-to-head between the four finishers

Player	1	2	3	4
1Nanne Van Foreest	*	—	1	—
2FMMilan Mostertman	—	*	½	1
3FMLeandro Slagboom	0	½	*	—
4Anastasios Koukas	—	0	—	*

Grille américaine

#	Player	Elo	Fed	R1	R2	R3	R4	R5	R6	R7	Pts	Bu C1	Bu	SB	Perf	Δ
1	Mostertman, MilanFM	2258	NED	+28N	+24B	+4N	=3B	=9N	+5B	+10N	6.0	29.0	33.0	28.00	2392	+21.0
2	Van Foreest, Nanne	1965	NED	+7N	=72B	+64N	=12B	+8N	+9B	+3N	6.0	27.0	29.5	26.00	2401	+70.8
3	Slagboom, LeandroFM	2334	NED	+71B	+33N	+6B	=1N	+11B	+10N	−2B	5.5	30.0	32.5	23.50	2307	-1.6
4	Koukas, Anastasios	2060	GRE	+65B	+78N	−1B	=6N	+41B	+19N	+9N	5.5	26.0	28.0	19.50	2245	+32.2
5	Blok, Xaveer	1898	NED	+36B	+29N	+14B	−9B	+16N	−1N	+21B	5.0	27.5	31.0	20.50	2177	+98.0
6	Bruggink, Tycho	2110	NED	+26N	+35B	−3N	=4B	+24N	=15B	+34N	5.0	27.5	31.0	20.50	2154	+7.2
7	Margarido, Jose Miguel Teixeira	2137	POR	−2B	+54N	+36B	=23N	+30B	=13N	+22B	5.0	26.0	29.0	18.75	2095	-6.0
8	Baarspul, Bram	2173	NED	−22B	+37N	+39B	+21N	−2B	+27N	+23B	5.0	25.5	29.0	19.00	2089	-24.0
9	De Rover, Yong HoonIM	2295	NED	+20B	+13N	+25B	+5N	=1B	−2N	−4B	4.5	31.5	35.5	21.00	2126	-11.8
10	Botter, Simon	2045	NED	=38N	+18B	+51N	+11B	+12N	−3B	−1B	4.5	28.5	31.5	18.25	2161	+44.4
11	Keuning, Selwin	2200	NED	+19B	+22N	+17B	−10N	−3N	=36B	+35N	4.5	26.5	30.0	18.25	2168	-2.8
12	Van Foreest, Pieter	1828	NED	+87N	+28B	+53N	=2N	−10B	=26B	=15N	4.5	26.0	27.0	15.25	2085	+39.8
13	Huiskes, Mathijs	1981	NED	+43N	−9B	=27N	+51B	+35N	=7B	=18N	4.5	25.0	28.0	16.75	2110	+23.8
14	Jakovlev, Saveliy	2072	NED	=31N	+38B	−5N	+34B	=26N	+58B	=16N	4.5	25.0	28.0	16.75	1971	-28.0
15	Knol, Geon	2007	NED	+30B	−17N	+78B	=25N	+50B	=6N	=12B	4.5	25.0	27.0	15.75	2061	+12.0
16	Schuttevaer, Tim	1727	NED	=50B	=80N	+46B	+20N	−5B	+42N	=14B	4.5	24.0	26.0	16.25	1982	+45.2
17	Van Osch, MeesFM	2342	NED	+47N	+15B	−11N	F	=21B	+39B	+31N	4.5	24.0	24.0	17.50	2160	-16.4
18	Aden, Tammo	2147	GER	=21B	−10N	+50B	+77N	+37B	=23N	=13B	4.5	23.5	25.5	14.75	2022	-18.2
19	Wierenga, Jael	1941	NED	−11N	+66B	=84N	+32B	+64N	−4B	+36N	4.5	22.5	24.0	13.25	2013	+14.2
20	Kelder, Sjoerd	1932	NED	−9N	+70B	=77N	−16B	+75N	+64B	+32N	4.5	20.0	22.0	12.00	1943	+2.2
21	Aden, Keno	1963	GER	=18N	+31B	+32N	−8B	=17N	+61B	−5N	4.0	27.0	30.0	15.50	2025	+11.4
22	Rajkumar Emmanuel	1964	IND	+8N	−11B	=43N	+59B	=27N	+40B	−7N	4.0	25.5	28.5	15.25	2019	+21.2
23	Ellenbroek, Ton	1989	NED	−27N	+41B	+60N	=7B	+38N	=18B	−8N	4.0	25.5	28.5	14.75	2033	+8.6
24	Leenes, Robert	2002	NED	+53B	−1N	=30B	+69N	−6B	+52N	=29B	4.0	25.0	27.5	12.50	2042	+7.6
25	Clemens, AdrianFM	2073	NED	+45N	+27B	−9N	=15B	=31N	−34B	+58N	4.0	24.5	27.5	14.75	2002	-12.0
26	Hannessen, Jonathan	0	NED	−6B	+52N	+29B	=72N	=14B	=12N	=41B	4.0	24.5	27.0	14.50	1981	0.0
27	Elsinga, Brian	1857	NED	+23B	−25N	=13B	+81N	=22B	−8B	+61N	4.0	24.5	26.5	13.25	1961	+20.2
28	Van de Poel, Taco	1944	NED	−1B	−12N	+62N	+83B	+69B	=29N	=30B	4.0	24.0	26.0	11.50	1928	-3.4
29	Kolijn, David	1916	NED	+44N	−5B	−26N	+67B	+55N	=28B	=24N	4.0	23.5	26.0	13.00	1973	+22.0
30	Brand, Niels	1879	NED	−15N	+67B	=24N	+55B	−7N	+68B	=28N	4.0	23.0	25.5	12.00	1933	+11.4
31	Timmer, Michel	1888	NED	=14B	−21N	+68B	+84N	=25B	+54N	−17B	4.0	22.5	24.0	11.25	2043	+27.0
32	Nair, Pranav Prasobh	1747	NED	+89B	+65N	−21B	−19N	+43B	+45N	−20B	4.0	22.5	23.5	10.50	1906	+60.0
33	Kanters, Cor	2024	NED	+60N	−3B	−35N	+52B	−40N	+59B	+69N	4.0	21.5	24.0	11.50	1950	-12.6
34	Van den Bos, Frans Pieter	1844	NED	+76B	−53N	+75B	−14N	+74B	+25N	−6B	4.0	20.5	22.5	10.00	1986	+25.0
35	Hendriks, Peter	1929	NED	+46B	−6N	+33B	=42N	−13B	+50N	−11B	3.5	25.0	28.0	12.25	1992	+12.2
36	Visser, Berend	1904	NED	−5N	+74B	−7N	+48B	+84B	=11N	−19B	3.5	24.5	26.0	9.25	1912	-1.0
37	Bloemhof, Ruben	1857	NED	+63N	−8B	=56N	+53B	−18N	=72B	=39N	3.5	22.0	24.5	10.50	1998	+23.0
38	Aden, Dagmar	1856	GER	=10B	−14N	+57B	+74N	−23B	=62N	=54B	3.5	22.0	24.0	10.25	1859	-0.6
39	Aden, Meino	1924	GER	−72N	+59B	−8N	+56B	+70B	−17N	=37B	3.5	21.5	24.0	10.25	1966	+5.2
40	Jovanovic, Luka L	1765	NED	+92N	−42B	−55N	+76B	+33B	−22N	=44B	3.5	20.0	20.5	8.25	1868	+18.0
41	Spears, Russell	1838	NED	+81B	−23N	+76B	F	−4N	+71B	=26N	3.5	20.0	20.0	8.50	1915	+11.2
42	Faber, Ab	1958	NED	−78B	+40N	F	=35B	+51N	−16B	+55N	3.5	19.5	19.5	11.25	1845	-15.8
43	Dijkstra, Edwin	1901	NED	−13B	+75N	=22B	F	−32N	+79N	+53B	3.5	19.5	19.5	9.00	1941	+7.0
44	Zuiderweg, Edwin	1979	NED	−29B	−51N	+49B	−50N	+80N	+74B	=40N	3.5	19.0	21.0	9.25	1735	-40.6
45	Bodewes, Peter	1911	NED	−25B	+68N	=69B	F	+59N	−32B	+51N	3.5	19.0	19.0	9.75	1889	-3.2
46	Ambrona Navarro, Himar	2056	ESP	−35N	=77B	−16N	+85N	+56B	F	+60B	3.5	18.0	19.5	8.50	1880	-48.4
47	FIDE 40130908	0	—	−17B	−64N	=79B	+57N	−68N	+67B	+75N	3.5	17.0	19.0	8.50	1779	0.0
48	Brzezinski, Tomasz	0	NED	−51B	+89N	=54B	−36N	−52N	+82B	+66N	3.5	17.0	18.0	7.00	1768	0.0
49	Hall, Gary	1644	ENG	−70N	+63B	−44N	−66B	+93N	=65B	+83B	3.5	16.0	16.0	6.25	1764	+34.0
50	Veenstra, Klaas-Jan	1612	NED	=16N	+83B	−18N	+44B	−15N	−35B	=68N	3.0	23.0	25.0	9.00	1838	+68.4
51	Van Essen, Tobias	1787	NED	+48N	+44B	−10B	−13N	−42B	+81N	−45B	3.0	23.0	25.0	9.00	1782	-2.4
52	Blokzijl, Ruben	1846	NED	+61N	−26B	=67N	−33N	+48B	−24B	=57N	3.0	21.5	24.0	9.25	1731	-12.6
53	Kamphuis, Jasper	2134	NED	−24N	+34B	−12B	−37N	+82N	+84B	−43N	3.0	21.5	23.0	7.50	1810	-55.2
54	Vermeulen, Frans	1878	NED	+56N	−7B	=48N	F	+81B	−31B	=38N	3.0	21.0	21.0	8.50	1836	-5.0
55	Haase, Jelle	1650	GER	−64B	+86N	+40B	−30N	−29B	+70N	−42B	3.0	20.0	21.5	7.50	1737	+28.0
56	Mostertman, Johan	1736	NED	−54B	+82N	=37B	−39N	−46N	=57B	+84N	3.0	18.5	20.0	6.75	1796	+7.6
57	FIDE 40132366	0	—	+93N	−60B	−38N	−47B	+67N	=56N	=52B	3.0	18.5	18.5	5.50	1713	0.0
58	Huizinga, Egbert	1863	NED	−75B	+73B	−74N	+63N	+79B	−14N	−25B	3.0	18.0	20.0	7.50	1759	-19.2
59	Van Soest, Sjoerd	1752	NED	+91B	−39N	+80B	−22N	−45B	−33N	+87B	3.0	18.0	18.5	3.50	1782	+3.8
60	Prijs, Xander	1872	NED	−33B	+57N	−23B	F	+89N	+66B	−46N	3.0	18.0	18.0	6.50	1824	-5.8
61	De Kleine, Rick	1630	NED	−52B	−76N	+86B	+90N	+77B	−21N	−27B	3.0	16.5	17.5	4.50	1723	+30.0
62	Andrieu, Justin	1727	NED	−77N	F	−28B	+87B	+65N	=38B	=71N	3.0	15.5	15.5	6.50	1840	+35.2
63	De Leur, Wouter	1751	NED	−37B	−49N	+92N	−58B	+91N	F	+79B	3.0	13.0	13.0	3.00	1778	+8.4
64	Bosveld, Mattias	1756	NED	+55N	+47B	−2B	=71N	−19B	−20N	F	2.5	24.0	24.0	7.75	1733	-3.6
65	Norden, Marc	1793	NED	−4N	−32B	+73N	F	−62B	=49N	+76B	2.5	20.5	20.5	6.25	1669	-20.6
66	Spaans, Leonie	1860	NED	+82B	−19N	−81B	+49N	=71B	−60N	−48B	2.5	19.0	21.0	6.75	1692	-25.4
67	Haschke, Oliver	1614	GER	+90B	−30N	=52B	−29N	−57B	−47N	+85B	2.5	19.0	20.0	4.00	1846	+57.2
68	Beijer, Bart	1826	NED	+88N	−45B	−31N	F	+47B	−30N	=50B	2.5	19.0	19.0	6.00	1501	-29.8
69	Abma, Klaas	1804	NED	+85B	F	=45N	−24B	−28N	+76N	−33B	2.5	19.0	19.0	5.25	1838	+4.4
70	Karsdorp, Nico	1804	NED	+49B	−20N	=85B	F	−39N	−55B	+74N	2.5	18.0	18.0	6.25	1735	-12.2
71	Morsch, Tjeerd	1922	NED	−3N	F	+90B	=64B	=66N	−41N	=62B	2.5	18.0	18.0	5.00	1823	-38.4
72	Hulshof, Peter	2119	NED	+39B	=2N	F	=26B	F	=37N	F	2.5	17.0	17.0	10.25	2040	-5.6
73	Sarathbabu, Mrityunjay	1503	NED	=79B	−58N	−65B	=86N	−76N	=80B	+88N	2.5	13.0	14.0	3.75	1504	-4.8
74	Van der Graaf, Jaap	1786	NED	+86B	−36N	+58B	−38B	−34N	−44N	−70B	2.0	20.0	21.5	4.50	1654	-23.2
75	Schoutens, Gijs	1699	NED	+58N	−43B	−34N	F	−20B	+85N	−47B	2.0	20.0	20.0	4.50	1799	+12.4
76	Ris, Gert-Jan	1677	NED	−34N	+61B	−41N	−40N	+73B	−69B	−65N	2.0	19.0	21.5	5.50	1582	-18.4
77	Jorritsma, Eli Alia	1861	NED	+62B	=46N	=20B	−18B	−61N	F	F	2.0	18.5	18.5	7.00	1826	-11.2
78	Almefalani, Abdulhay	1867	NED	+42N	−4B	−15N	F	+85B	F	F	2.0	18.5	18.5	5.00	1960	+19.2
79	Haschke, Simon	1779	GER	=73N	−84B	=47N	+80B	−58N	−43B	−63N	2.0	17.5	19.0	5.00	1558	-66.8
80	Bakker, Hannah	1634	NED	F	=16B	−59N	−79N	−44B	=73N	+86B	2.0	17.0	17.0	5.00	1571	-22.8
81	Van t Riet, Flip	1565	NED	−41N	+93B	+66N	−27B	−54N	−51B	F	2.0	16.0	16.0	2.50	1604	+6.8
82	Ma, Ying Hao	1549	NED	−66N	−56B	+88N	F	−53B	−48N	+93B	2.0	13.0	13.0	1.00	1048	-9.6
83	Cats, Sven	1736	NED	F	−50N	+91B	−28N	F	+88B	−49N	2.0	12.0	12.0	1.50	1533	-43.2
84	Fahner, Jurrian	1853	NED	F	+79N	=19B	−31B	−36N	−53N	−56B	1.5	20.0	20.0	4.25	1704	-47.2
85	Tilburgs, Mark	1813	NED	−69N	+88B	=70N	−46B	−78N	−75B	−67N	1.5	15.0	16.0	2.25	1406	-102.4
86	De Vries, Christiaan	1434	NED	−74N	−55B	−61N	=73B	−88B	+93N	−80N	1.5	13.5	13.5	1.25	1275	-28.8
87	Jorritsma, Johan	1665	NED	−12B	−90N	−89B	−62N	F	+91B	−59N	1.0	13.0	13.0	0.50	1449	-30.6
88	Veluwenkamp, Herman	0	NED	−68B	−85N	−82B	F	+86N	−83N	−73B	1.0	12.0	12.0	1.50	1371	0.0
89	Kempenaar, Jane	1549	NED	−32N	−48B	+87N	F	−60B	F	F	1.0	11.5	11.5	1.00	1636	+5.8
90	Qatina, Waheeb	1775	NED	−67N	+87B	−71N	−61B	F	F	F	1.0	9.0	9.0	1.00	1515	-27.0
91	Ma, Yuan Li	1702	NED	−59N	=92B	−83N	F	−63B	−87N	F	0.5	9.5	9.5	0.25	1379	-68.0
92	Van Dijk, Simon	1821	NED	−40B	=91N	−63B	F	F	F	F	0.5	7.0	7.0	0.25	1466	-53.6
93	FIDE 40129225	0	—	−57B	−81N	F	F	−49B	−86B	−82N	0.0	12.0	12.0	0.00	748	0.0

Key insights

Biggest movers and upsets — the story behind the numbers.

Top rating gainers

1Blok, XaveerNED
+98.0
5.0 pts · #7
2Van Foreest, NanneNED
+70.8
6.0 pts · #1
3Veenstra, Klaas-JanNED
+68.4
3.0 pts · #47

Top rating losers

1Tilburgs, MarkNED
-102.4
1.5 pts · #91
2Ma, Yuan LiNED
-68.0
0.5 pts · #89
3Haschke, SimonGER
-66.8
2.0 pts · #77

Biggest upsets

R7+369 Elo gap
Van Foreest, Nanne1965 beat FMSlagboom, Leandro2334
R4+367 Elo gap
Veenstra, Klaas-Jan1612 beat Zuiderweg, Edwin1979
R6+330 Elo gap
Van Foreest, Nanne1965 beat IMDe Rover, Yong Hoon2295