JK

Jacques Koolstra

Rated since January 2023

1633 Classic
1691 Rapid
1633 Blitz

RIVALRY

Nemesis
Kips, D. (David)
Games: 5 · Win rate: 60%
Kryptonite
Pelleboer, P. (Pieter)
Games: 5 · Win rate: 0%
Easy Target
Kraay, J. (Jos)
Games: 5 · Win rate: 100%

The good & the bad

Best wins
HUIJSER, L.J. (LEON) 1887
9057 EsPion interne competitie 2023-2024 Voorjaar ronde 11-14 · Monday 6 May 2024
ENSERINK, H. (HENK) 1822
8654 EsPion interne competitie 2023-2024 Voorjaar ronde 2-5 · Monday 18 March 2024
STEENSMA, F. (FRANK) 1807
9057 EsPion interne competitie 2023-2024 Voorjaar ronde 11-14 · Monday 29 April 2024
TJONG-AKIET, R. (RAF) 1788
8859 EsPion interne competitie 2023-2024 Voorjaar ronde 6-10 · Monday 22 April 2024
VELLEKOOP, A. (ALFRED) 1784
13957 S.V. EsPion interne competitie 15-06-2026 t/m 06-08-2026 (080015) · Monday 22 June 2026
Worst losses
LOOMAN, J.F.M. (HANS) 1254
8309 EsPion interne competitie 2023-2024 Ronde 12 - 14 · Monday 15 January 2024
STOLP, H.P. (PETER) 1342
7047 EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 8 - 12 · Monday 3 April 2023
KOOPMAN, G.J.K. (GABRIELLA) 1434
12889 S.V. EsPion interne competitie 02-02-2026 t/m 23-02-2026 (080015) · Monday 9 February 2026
PLANTFEBER, H.J. (HENK) 1456
7712 EsPion interne competitie 2023-2024 Ronde 1-4 · Monday 16 October 2023
BEZEMER, C. (CASPER) 1503
11861 S.V. EsPion interne competitie 03-11-2025 t/m 24-11-2025 (080015) · Monday 3 November 2025
No FIDE-rated tournaments found.
S.V. EsPion interne competitie 06-07-2026 t/m 27-07-2026 (080015) Monday 8 June 2026 +8–2=2 +60.7
S.V. EsPion interne competitie 15-06-2026 t/m 06-08-2026 (080015) Monday 8 June 2026 +3–5=0 +4.9
S.V. EsPion interne competitie 11-05-2026 t/m 25-05-2026 (080015) Monday 2 February 2026 +1–0=0 +8.9
S.V. EsPion interne competitie 31-03-2026 t/m 20-04-2026 (080015) Monday 2 February 2026 +1–1=0 -8.7
S.V. EsPion interne competitie 02-03-2026 t/m 23-03-2026 (080015) Monday 2 February 2026 +2–2=0 +17.1
S.V. EsPion interne competitie 02-02-2026 t/m 23-02-2026 (080015) Monday 2 February 2026 +1–2=1 -16.2
SGA Competitie 2025-2026 Viertallen ronde 1 en 5 Wednesday 1 October 2025 +0–0=1 -1.9
S.V. EsPion interne competitie 05-01-2026 t/m 26-01-2026 (080015) Monday 22 September 2025 +1–2=1 +0.7
S.V. EsPion interne competitie 01-12-2025 t/m 22-12-2025 (080015) Monday 22 September 2025 +1–2=0 -7.1
S.V. EsPion interne competitie 03-11-2025 t/m 24-11-2025 (080015) Monday 22 September 2025 +1–1=1 -14.8
S.V. EsPion interne competitie 29-09-2025 t/m 27-10-2025 (080015) Monday 22 September 2025 +2–1=0 +13.3
S.V. EsPion interne competitie 22-09-2025 t/m 22-09-2025 (080015) Monday 22 September 2025 +0–1=0 -2.9
S.V. EsPion interne competitie 28-07-2025 t/m 25-08-2025 (080015) Monday 2 June 2025 +6–1=0 +35.3
S.V. EsPion interne competitie 30-06-2025 t/m 21-07-2025 (080015) Monday 2 June 2025 +1–4=2 -18.8
S.V. EsPion interne competitie 02-06-2025 t/m 23-06-2025 (080015) Monday 2 June 2025 +2–5=1 -35.6
S.V. EsPion interne competitie 12-05-2025 t/m 26-05-2025 (080015) Monday 3 February 2025 +0–1=0 -9.4
S.V. EsPion interne competitie 31-03-2025 t/m 28-04-2025 (080015) Monday 3 February 2025 +1–1=2 -9.9
S.V. EsPion interne competitie 03-03-2025 t/m 24-03-2025 (080015) Monday 3 February 2025 +1–0=1 +14.9
S.V. EsPion interne competitie 03-02-2025 t/m 24-02-2025 (080015) Monday 3 February 2025 +0–3=1 -38.8
S.V. EsPion interne competitie 27-01-2025 t/m 27-01-2025 (080015) Monday 23 September 2024 +0–0=1 +2.9
S.V. EsPion interne competitie 06-01-2025 t/m 20-01-2025 (080015) Monday 23 September 2024 +1–1=0 -4.3
S.V. EsPion interne competitie 28-10-2024 t/m 23-12-2024 (080015) Monday 23 September 2024 +3–4=1 -12.4
S.V. EsPion interne competitie 23-09-2024 t/m 21-10-2024 (080015) Monday 23 September 2024 +1–1=0 -8.5
EsPion interne competitie 2023-2024 Voorjaar ronde 15-17 Monday 2 October 2023 +0–3=0 -41.3
EsPion interne competitie 2023-2024 Voorjaar ronde 11-14 Monday 2 October 2023 +2–2=0 +15.5
EsPion interne competitie 2023-2024 Voorjaar ronde 6-10 Monday 2 October 2023 +2–2=0 +7.4
EsPion interne competitie 2023-2024 Voorjaar ronde 2-5 Monday 2 October 2023 +2–1=0 +12.9
EsPion interne competitie 2023-2024 Ronde 1 Monday 2 October 2023 +1–0=0 +18.1
EsPion interne competitie 2023-2024 Ronde 15 - 17 Monday 2 October 2023 +1–1=0 +11.3
EsPion interne competitie 2023-2024 Ronde 12 - 14 Monday 2 October 2023 +2–1=0 -8.5
EsPion interne competitie 2023-2024 Ronde 9 - 11 Monday 2 October 2023 +1–1=0 -5.8
EsPion interne competitie 2023-2024 Ronde 5-8 Monday 2 October 2023 +1–1=1 -1.3
EsPion interne competitie 2023-2024 Ronde 1-4 Monday 2 October 2023 +1–2=1 -16.8
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 17 Monday 26 September 2022 +0–0=1 -8.5
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 13 - 16 Monday 26 September 2022 +0–1=0 -9.6
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 8 - 12 Monday 26 September 2022 +1–2=1 -26.4
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 4 - 7 Monday 26 September 2022 +1–2=0 -2.1
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 1 - 3 Monday 26 September 2022 +2–1=0 +0.7
EsPion Interne competitie 2022-2023 Najaar 2022 Ronde 17 Monday 26 September 2022 +0–1=0 -12.9
EsPion Interne competitie 2022-2023 Najaar 2022 Ronde 14-16 Monday 26 September 2022 +2–1=0 +5.0
EsPion Interne competitie 2022-2023 Najaar 2022 ronde 10-13 Monday 26 September 2022 +2–1=1 -2.2

Rating History

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Peak Ratings

Classic 1750 June 1, 2024
Rapid 1691 Aug. 1, 2026
Blitz 1633 April 1, 2026

Games

Wins 58
Losses 63
Draws 20
Win Rate 41%

Performance by Color

Color Wins Draws Losses Win Rate
White 29 10 31 41%
Black 29 10 32 41%

Recent Matches

Kips, D. (David) (1651) Monday 27 July 2026 LOSS -11.6
Koolstra, J.R. (Jan) (1585) Monday 27 July 2026 WIN +11.1
Stolp, H.P. (Peter) (1488) Monday 27 July 2026 WIN +7.9
Haan de, P. (Peter) (1470) Monday 20 July 2026 WIN +7.3
Berkelmans, W. (Wim) (1551) Monday 20 July 2026 WIN +10.0
Boom, H. (Harrie) (1563) Monday 20 July 2026 WIN +10.4
Ran, M. (Mart) (1805) Monday 13 July 2026 DRAW +5.9
Heima, H.J.M. (Henny) (1597) Monday 13 July 2026 LOSS -13.5
Stokman, L.N. (Lennart) (1616) Monday 13 July 2026 WIN +12.2
Rijn van, A. (André) (1667) Monday 6 July 2026 WIN +14.0
Kerkhoff, F.C. (Frans) (1580) Monday 6 July 2026 WIN +10.9
Vaassen, M. (Mick) (1512) Monday 6 July 2026 DRAW -3.8
Bezemer, C. (Casper) (1555) Monday 29 June 2026 WIN +10.1
Schalekamp, R. (Rob) (1659) Monday 29 June 2026 WIN +13.7
Pelleboer, P. (Pieter) (1853) Monday 29 June 2026 LOSS -5.3
Dernier, R.P. (Raymond) (1752) Monday 22 June 2026 LOSS -8.2
Steensma, F. (Frank) (1715) Monday 22 June 2026 LOSS -9.4
Vellekoop, A. (Alfred) (1784) Monday 22 June 2026 WIN +17.8
Slooten van, R. (Rob) (1727) Monday 15 June 2026 LOSS -9.0
Metz, J. (Johan) (1879) Monday 15 June 2026 LOSS -4.7