Dutch Open 2025 - Reserve C

Open SwissStandard

37 players participated in this 9-round tournament, held from 22 Jul 2025 to 30 Jul 2025 in Dieren, Netherlands. 3 federations represented. Top 10 Elo average was 1691, and top seed was Roy Pieper (🇳🇱 NED, 1793).

Roy Pieper (🇳🇱 NED, 1793) won with 8.0/9, ahead of Sebastiaan De Jong (8.0) and Jack Makaij (6.5). Pieper won on tie-break after catching the field in the final round.

The biggest upset came in round 1: Rene Schoenmakers (1457) beat Rob Van Dongen (1754), a +297-point gap.

Location

🇳🇱Dieren, Netherlands

Dates

22 Jul 2025 → 30 Jul 2025

Time control

Standard: 90min/40moves+30min/end+30sec increment per move starting from move 1

System

Swiss · 9 rounds

Top seed

🇳🇱Roy Pieper1793

Avg top 10

1,691

Participants

Federations · 3 represented

🇳🇱Netherlands×32

🇩🇪Germany×2

🇧🇪Belgium×1

Top 3

🥇
Roy Pieper
🇳🇱NED·1793
8.0pts·2447perf+74.8
🥈
Sebastiaan De Jong
🇳🇱NED
8.0pts·1737perf0.0
🥉
Jack Makaij
🇳🇱NED
6.5pts·1770perf0.0

How it unfolded

Top 6 · 9 rounds

Tight race until R4; 2 players tied at 8.0/9, decided on Buchholz.

Co-leaders

De Jong8Pieper8Makaij6.5Van Leeuwen6Van Oostenbrugge5.5Elferink5.5

R4–R9 · LEAD HELD

Sebastiaan De Jong held the sole lead from R4 through R9 without losing it.

R9 · TIEBREAK CLUSTER

2 players finish on 8.0/9. Pieper takes the title on Buchholz Cut1 (46.5).

R4 · HEAD-TO-HEAD · WINNER VS 2ND

Sebastiaan De Jong beat Roy Pieper (Black).

Key matchups · top 4

Head-to-head between the four finishers

Player	1	2	3	4
1Sebastiaan De Jong	*	1	1	—
2Roy Pieper	0	*	1	1
3Jack Makaij	0	0	*	—
4Dick Van Leeuwen	—	0	—	*

Grille américaine

#	Player	Elo	Fed	R1	R2	R3	R4	R5	R6	R7	R8	R9	Pts	Bu C1	Bu	SB	Perf	Δ
1	Pieper, Roy	1793	NED	+19N	+3B	+5N	−2B	+4N	+8N	+9B	+7B	+12N	8.0	46.5	51.0	43.00	2447	+74.8
2	De Jong, Sebastiaan	0	NED	+23N	+13B	+17N	+1N	=8B	+3B	+7N	+5B	=6N	8.0	45.5	49.5	44.25	1737	0.0
3	Makaij, Jack	0	NED	+29B	−1N	+11B	+34N	+6B	−2N	+10B	=8N	+5B	6.5	45.0	47.0	28.50	1770	0.0
4	Van Leeuwen, Dick	0	NED	=22B	+25N	+27B	+16N	−1B	=9N	=8B	=6N	+11B	6.0	41.0	44.0	26.25	1796	+69.2
5	Van Oostenbrugge, Gert-Jan	1637	NED	+30N	+24B	−1B	=22N	+16B	+18N	+14B	−2N	−3N	5.5	44.5	47.5	23.00	1887	+31.6
6	De Vreeze, Frans	1687	NED	−13N	+23B	+14N	=17B	−3N	+21B	+22N	=4B	=2B	5.5	43.5	47.5	26.75	1671	-0.8
7	Elferink, Duncan	1537	NED	=27B	+35N	+10B	−8B	+17N	+22N	−2B	−1N	+21B	5.5	42.0	43.0	20.50	1712	+54.8
8	Egelie, Peter	0	NED	+21B	+9N	=16B	+7N	=2N	−1B	=4N	=3B	−14B	5.0	48.5	53.0	27.50	1807	+7.2
9	Geussens, Patrick	1664	BEL	+31N	−8B	+37N	+12B	=18N	=4B	−1N	=15B	=10B	5.0	41.5	41.5	18.25	1670	0.0
10	Van Harxen, Luc	0	NED	+14N	=18B	−7N	=20B	=13N	+16B	−3N	+22B	=9N	5.0	40.5	44.5	23.00	1641	-46.8
11	Lopez Janssen, Manuel	1524	GER	−12N	+19B	−3N	+33B	=15N	=17B	+29N	+20B	−4N	5.0	39.0	41.0	18.75	1770	+68.8
12	Slottje, Pim	1631	NED	+11B	−16N	+33B	−9N	−22B	+31N	+28B	+18N	−1B	5.0	37.0	39.0	17.50	1630	0.0
13	Doorn, Wouter	1596	NED	+6B	−2N	−34B	+37N	=10B	F	+16N	+24B	=15N	5.0	34.0	34.0	19.00	1809	+68.0
14	Valk, Roland	0	NED	−10B	+36N	−6B	+31N	+34B	F	−5N	+17B	+8N	5.0	33.5	33.5	14.50	1634	0.0
15	Van den Dool, Gerrit	1692	NED	=35B	−27N	+25B	−28N	=11B	+26N	+23B	=9N	=13B	5.0	33.0	34.0	20.00	1588	-17.6
16	Jorritsma, Johan	1679	NED	+26N	+12B	=8N	−4B	−5N	−10N	−13B	+35B	+23N	4.5	39.5	40.5	16.50	1616	-22.0
17	Hamers, Peter	0	NED	+36B	+33N	−2B	=6N	−7B	=11N	+24B	−14N	=18B	4.5	39.5	39.5	13.50	1602	0.0
18	Smit, Tom	1673	NED	+37B	=10N	=22B	+27N	=9B	−5B	=20N	−12B	=17N	4.5	36.5	36.5	14.50	1596	-13.2
19	Westerhof, Siem	1625	NED	−1B	−11N	+26N	+23B	−24N	−29B	+35N	+30B	=20N	4.5	35.5	36.5	14.25	1567	-21.6
20	Van der Beek, Simon	1696	NED	=25B	−22N	+35B	=10N	+28B	=24N	=18B	−11N	=19B	4.5	34.0	35.0	15.00	1614	-15.0
21	Vaillant, Paul	1617	NED	−8N	=26B	−24N	+36B	+25N	−6N	+27B	+29B	−7N	4.5	34.0	34.0	12.00	1501	-37.2
22	Hamers, Bram	0	NED	=4N	+20B	=18N	=5B	+12N	−7B	−6B	−10N	=24N	4.0	41.5	45.5	19.50	1617	0.0
23	Trunz, Daniel	1425	GER	−2B	−6N	+36B	−19N	+27B	+25B	−15N	+28N	−16B	4.0	37.5	37.5	10.00	1509	+22.4
24	Hoogerwaard, Samantha	1623	NED	+34B	−5N	+21B	−32N	+19B	=20B	−17N	−13N	=22B	4.0	35.5	37.5	15.25	1651	+10.0
25	Makkinje, Jeroen	1621	NED	=20N	−4B	−15N	+30B	−21B	−23N	+31B	=27N	+28B	4.0	33.0	36.0	12.75	1442	-28.6
26	Mooij, Remko	0	NED	−16B	=21N	−19B	=35N	+36N	−15B	−30N	+33N	+27B	4.0	27.5	27.5	7.75	1474	0.0
27	Mahabiersing, Caspar	1496	NED	=7N	+15B	−4N	−18B	−23N	+33B	−21N	=25B	−26N	3.0	37.5	39.5	11.75	1525	+7.6
28	Van Deursen, Peter	0	NED	F	+29N	−32B	+15B	−20N	+30B	−12N	−23B	−25N	3.0	31.5	31.5	11.00	1455	0.0
29	Botland, Robin	0	NED	−3N	−28B	−30N	F	+35B	+19N	−11B	−21N	+33B	3.0	29.5	29.5	7.50	1522	0.0
30	Luijmes, Henk	1467	NED	−5B	−34N	+29B	−25N	+37B	−28N	+26B	−19N	−31B	3.0	29.0	29.0	7.00	829	-22.8
31	Ten Dam, Thijs	0	NED	−9B	−32N	F	−14B	+33N	−12B	−25N	+36B	+30N	3.0	27.0	27.0	5.00	1474	0.0
32	Van Dongen, Rob	1754	NED	−33N	+31B	+28N	+24B	F	F	F	F	F	3.0	17.0	17.0	10.00	1541	-20.8
33	Schoenmakers, Rene	1457	NED	+32B	−17B	−12N	−11N	−31B	−27N	+36N	−26B	−29N	2.0	30.5	30.5	3.00	1406	-11.2
34	Heins, Ricardo	1632	NED	−24N	+30B	+13N	−3B	−14N	F	F	F	F	2.0	23.5	23.5	8.00	1688	+8.8
35	Van Diggelen, Samantha	0	NED	=15N	−7B	−20N	=26B	−29N	F	−19B	−16N	F	1.0	31.0	31.0	4.50	1280	-30.0
36	FIDE 40121941	0	—	−17N	−14B	−23N	−21N	−26B	F	−33B	−31N	F	0.0	28.0	28.0	0.00	700	0.0
37	FIDE 40122077	0	—	−18N	F	−9B	−13B	−30N	F	F	F	F	0.0	18.5	18.5	0.00	800	0.0

Key insights

Biggest movers and upsets — the story behind the numbers.

Top rating gainers

1Pieper, RoyNED
+74.8
8.0 pts · #2
2Van Leeuwen, DickNED
+69.2
6.0 pts · #3
3Lopez Janssen, ManuelGER
+68.8
5.0 pts · #15

Top rating losers

1Van Harxen, LucNED
-46.8
5.0 pts · #20
2Vaillant, PaulNED
-37.2
4.5 pts · #24
3Van Diggelen, SamanthaNED
-30.0
1.0 pts · #34

Biggest upsets

R1+297 Elo gap
Schoenmakers, Rene1457 beat Van Dongen, Rob1754
R2+196 Elo gap
Mahabiersing, Caspar1496 beat Van den Dool, Gerrit1692
R6+196 Elo gap
Trunz, Daniel1425 beat Makkinje, Jeroen1621