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Klaas Buwalda

FORTE | Brazilian Jiu Jitsu

W–L
6–10
Won and lost rating-eligible matches in the past 12 months.
Gi
1,246
Rating based on Gi matches in the past 12 months.
No-Gi
-
Rating based on No-Gi matches in the past 12 months.
Current form
4–6
Results from the ten most recent rating-eligible matches.
Opponents
14
Unique opponents faced in rating-eligible matches in the past 12 months.

Indexed career

Matches

37
Indexed competition matches
Date Opponent Result Event Division
2026-03-28 You An Sun
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Gi · Kids GI / 10 - 12 years / White & Grey / -34 kg
2026-03-28 Luka Receveur
Loss
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Gi · Kids GI / 10 - 12 years / White & Grey / -34 kg
2026-03-28 Abdellah Achnak
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Gi · Kids GI / 10 - 12 years / White & Grey / -34 kg
2026-03-28 Serafin Veenendaal
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Gi · Kids GI / 10 - 12 years / White & Grey / -34 kg
2025-11-30 Seymen Efe CAGLAR
Loss
The Future League 8 – Gi & No-Gi Gi · Gi-10
2025-11-30 Jalil Muntar
Loss
The Future League 8 – Gi & No-Gi Gi · Gi-10
2025-11-30 Jefta Vis
Loss
The Future League 8 – Gi & No-Gi Gi · Gi-10
2025-10-25 Ayoub El Atrach
Loss
Lion Cub Jiu Jitsu Competition 5 Gi · Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
2025-10-25 Seymen Efe CAGLAR
Win
Lion Cub Jiu Jitsu Competition 5 Gi · Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
2025-10-25 Mohammad Imraan Ahmadi
Loss
Lion Cub Jiu Jitsu Competition 5 Gi · Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
2025-10-25 Jefta Vis
Win
Lion Cub Jiu Jitsu Competition 5 Gi · Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
2025-10-25 Zachary CARLHIAN
Loss
Lion Cub Jiu Jitsu Competition 5 Gi · Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
2025-09-21 Jonge Pennings
Loss
'The Future League 7' by VERSUS Gi · -30&-34kg / 8&9yr / White&Grey
2025-09-21 Leonardo Tancredi
Win
'The Future League 7' by VERSUS Gi · -30&-34kg / 8&9yr / White&Grey
2025-09-21 Zubayr Khan
Win
'The Future League 7' by VERSUS Gi · -30&-34kg / 8&9yr / White&Grey
2025-09-07 Noud Maes
Loss
Gelders Open BJJ Gi · Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
2025-09-07 Daniël Van Drie
Loss
Gelders Open BJJ Gi · Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
2025-05-31 Tariq El Kaoui
Win
Nijmegen Open BJJ 2025 Gi · Kids / 8 - 9 years boys / Grey / -30 kg
2025-05-31 Nadir Balakouh
Loss
Nijmegen Open BJJ 2025 Gi · Kids / 8 - 9 years boys / Grey / -30 kg
2025-05-31 Hudhayfah Chikri
Win
Nijmegen Open BJJ 2025 Gi · Kids / 8 - 9 years boys / Grey / -30 kg
2024-10-19 Muhammad Hotak
Loss
Lion Cub Jiu Jitsu Competition 3 Gi · Boys / 8 - 9 Boys / Grey / -30 kg
2024-10-19 Anton Ten Doeschate
Loss
Lion Cub Jiu Jitsu Competition 3 Gi · Boys / 8 - 9 Boys / Grey / -30 kg
2024-10-19 Mohammad Imraan Ahmadi
Loss
Lion Cub Jiu Jitsu Competition 3 Gi · Boys / 8 - 9 Boys / Grey / -30 kg
2024-07-06 Jefta Vis
Loss
King of the Beach 2024 Gi · Sunday Kids Gi / 8 - 9 years boys / White & Grey / -30 kg
2024-07-06 Dalice Vermeulen
Win
King of the Beach 2024 Gi · Sunday Kids Gi / 8 - 9 years boys / White & Grey / -30 kg
2024-07-06 Sem Schildermans
Loss
King of the Beach 2024 Gi · Sunday Kids Gi / 8 - 9 years boys / White & Grey / -30 kg
2024-06-01 Zachary CARLHIAN
Loss
Nijmegen Open BJJ 2024 Gi · Kids / 8 - 9 years boys / Grey / -27 kg
2024-06-01 Jefta Vis
Loss
Nijmegen Open BJJ 2024 Gi · Kids / 8 - 9 years boys / Grey / -27 kg
2024-06-01 David Chan
Loss
Nijmegen Open BJJ 2024 Gi · Kids / 8 - 9 years boys / Grey / -27 kg
2024-03-30 Evan Gadella
Loss
Lion Cub Jiu Jitsu Competition 2 Gi · Boys / 8 - 9 Boys / Grey / -27 kg
2024-03-30 Zachary CARLHIAN
Loss
Lion Cub Jiu Jitsu Competition 2 Gi · Boys / 8 - 9 Boys / Grey / -27 kg
2023-10-21 Koi Penney Chavers
Loss
Lion Cub Jiu Jitsu Competition 1 Gi · Boys / 6 - 7 years / White / -27 & -30 kg
2023-10-21 Franco Hendriks
Loss
Lion Cub Jiu Jitsu Competition 1 Gi · Boys / 6 - 7 years / White / -27 & -30 kg
2023-10-21 Alexandre Tessier
Win
Lion Cub Jiu Jitsu Competition 1 Gi · Boys / 6 - 7 years / White / -27 & -30 kg
2023-06-03 Jefta Vis
Loss
Nijmegen Open BJJ 2023 Gi · Kids / 6 - 7 years / White & Grey / -24 kg
2023-06-03 Stefan Maigret
Win
Nijmegen Open BJJ 2023 Gi · Kids / 6 - 7 years / White & Grey / -24 kg
2023-06-03 Kobe Chavez
Loss
Nijmegen Open BJJ 2023 Gi · Kids / 6 - 7 years / White & Grey / -24 kg

Calculation details

Rating breakdown for the past 12 months

See the published month-end rating and the rating-eligible matches added in each month. Open a month for details.

August 2026 No new matches Change 0 Rating 1,246

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

July 2026 No new matches Change +1 Rating 1,246

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

June 2026 No new matches Change -4 Rating 1,245

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

May 2026 No new matches · 3 left period Change -51 Rating 1,249

Rating-period composition

Rating matches
16 -3
Record
6–10 Previous month 8–11
Opponents
14 -3
Events
5 -1

3 older matches left the 12-month period: 2 won and 1 lost. The rating is then recalculated across the full network, so the monthly change is not a sum of separate deductions.

April 2026 No new matches Change -1 Rating 1,300

Rating-period composition

Rating matches
19 0
Record
8–11 Previous month 8–11
Opponents
17 0
Events
6 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

March 2026 3 new matches Change +50 Rating 1,301

Rating-period composition

Rating matches
19 +3
Record
8–11 Previous month 6–10
Opponents
17 +3
Events
6 +1

New rating matches

This is a current what-if estimate: roughly how much the current rating changes when this match is omitted. These values cannot be added and therefore do not together explain the monthly change.
Win
March 28, 2026 You An Sun
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids GI / 10 - 12 years / White & Grey / -34 kg
Method Decision 03:00 0–0
Marginal influence +25
Loss
March 28, 2026 Luka Receveur
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids GI / 10 - 12 years / White & Grey / -34 kg
Method Points 03:00 2–4
Marginal influence -19
Win
March 28, 2026 Serafin Veenendaal
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids GI / 10 - 12 years / White & Grey / -34 kg
Method Points 03:00 7–0
Marginal influence +16
February 2026 No new matches Change +1 Rating 1,251

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

January 2026 No new matches Change -5 Rating 1,250

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

December 2025 No new matches Change 0 Rating 1,255

Rating-period composition

Rating matches
16 0
Record
6–10 Previous month 6–10
Opponents
14 0
Events
5 0

No matches were added or left the period. The change comes from the monthly revaluation of opponents across the full network.

November 2025 3 new matches Change -42 Rating 1,255

Rating-period composition

Rating matches
16 +3
Record
6–10 Previous month 6–7
Opponents
14 +1
Events
5 +1

New rating matches

This is a current what-if estimate: roughly how much the current rating changes when this match is omitted. These values cannot be added and therefore do not together explain the monthly change.
Loss
November 30, 2025 Seymen Efe CAGLAR
The Future League 8 – Gi & No-Gi Gi-10
Method Submission 01:32 2–0
Marginal influence -13
Loss
November 30, 2025 Jalil Muntar
The Future League 8 – Gi & No-Gi Gi-10
Method Points 03:00 0–7
Marginal influence -14
Loss
November 30, 2025 Jefta Vis
The Future League 8 – Gi & No-Gi Gi-10
Method Submission 00:59 0–0
Marginal influence -11
October 2025 5 new matches · 3 left period Change +48 Rating 1,297

Rating-period composition

Rating matches
13 +2
Record
6–7 Previous month 4–7
Opponents
13 +2
Events
4 0

3 older matches left the 12-month period: 0 won and 3 lost. The rating is then recalculated across the full network, so the monthly change is not a sum of separate deductions.

New rating matches

This is a current what-if estimate: roughly how much the current rating changes when this match is omitted. These values cannot be added and therefore do not together explain the monthly change.
Loss
October 25, 2025 Ayoub El Atrach
Lion Cub Jiu Jitsu Competition 5 Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
Method Points 03:00 2–4
Marginal influence -8
Win
October 25, 2025 Seymen Efe CAGLAR
Lion Cub Jiu Jitsu Competition 5 Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
Method Points 03:00 13–0
Marginal influence +13
Loss
October 25, 2025 Mohammad Imraan Ahmadi
Lion Cub Jiu Jitsu Competition 5 Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
Method Submission 00:42 0–0
Marginal influence -8
Win
October 25, 2025 Jefta Vis
Lion Cub Jiu Jitsu Competition 5 Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
Method Points 03:00 3–2
Marginal influence +15
Loss
October 25, 2025 Zachary CARLHIAN
Lion Cub Jiu Jitsu Competition 5 Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
Method Points 03:00 0–2
Marginal influence -10
September 2025 5 new matches Change +25 Rating 1,249

Rating-period composition

Rating matches
11 +5
Record
4–7 Previous month 2–4
Opponents
11 +5
Events
4 +2

New rating matches

This is a current what-if estimate: roughly how much the current rating changes when this match is omitted. These values cannot be added and therefore do not together explain the monthly change.
Loss
September 21, 2025 Jonge Pennings
'The Future League 7' by VERSUS -30&-34kg / 8&9yr / White&Grey
Method Submission 02:58 10–5
Marginal influence -10
Win
September 21, 2025 Leonardo Tancredi
'The Future League 7' by VERSUS -30&-34kg / 8&9yr / White&Grey
Method Points 03:00 16–0
Marginal influence +17
Win
September 21, 2025 Zubayr Khan
'The Future League 7' by VERSUS -30&-34kg / 8&9yr / White&Grey
Method Points 03:00 24–2
Marginal influence +21
Loss
September 7, 2025 Noud Maes
Gelders Open BJJ Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
Method Points 03:00 4–5
Marginal influence -22
Loss
September 7, 2025 Daniël Van Drie
Gelders Open BJJ Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
Method Points 03:00 0–9
Marginal influence -11
Relevant matches
11
Official ranking percentile
Top 76%
Performance
2.4 pp below expectation

11 weighted matches against 14 different opponents across 5 events

Weighted win rate
37.1%
Expected win rate
39.4%
Average opponent rating
1,283
Repeated-opponent share
12.5%
Network connectivity
87.6%

Classification evidence

Why U12?

Within the published period from 2025-09-01 through 2026-08-31, only competition ages recorded at events in the calculation year determine this outcome, with at most one vote per event. Without such an age, the most recent unambiguous earlier competition age is projected to the calculation year; bracket evidence is the final fallback. The newest evidence breaks a tie.

Evidence outcome

  • U12 1 event vote Selected outcome

Registrations and outcomes

International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
U12 · Counts
Kids GI / 10 - 12 years / White & Grey / -34 kg
  • Competition age 11
  • Registered age: u12
  • Source category: u12
The Future League 8 – Gi & No-Gi
Does not count
Gi-10
  • Competition age 10
  • Registered age: u12
  • Source category: u12
Lion Cub Jiu Jitsu Competition 5
Does not count
Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
  • Competition age 10
  • Registered age: u10
  • Source category: u10
'The Future League 7' by VERSUS
Does not count
-30&-34kg / 8&9yr / White&Grey
  • Competition age 10
  • Registered age: u10
  • Source category: u10
Gelders Open BJJ
Does not count
Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
  • Competition age 10
  • Registered age: u10
  • Source category: u10

Classification evidence

Why ≤ 34 kg?

This outcome uses at most one unambiguous upper weight limit per completed ranking event from 2025-09-01 through 2026-08-31. Only the three most recent eligible events are considered, and the lightest verified upper limit is selected. A higher division is not treated as measured body weight.

Evidence outcome

  • ≤ 34 kg 2 competition events Selected outcome
  • ≤ 38 kg 1 competition event

Registrations and outcomes

International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
≤ 34 kg · Counts as a competition event
Kids GI / 10 - 12 years / White & Grey / -34 kg
  • Registered weight class: -34 kg
  • Source competition limit: -34 kg

3 matches in the rating period

The Future League 8 – Gi & No-Gi
Does not count
Gi-10

3 matches in the rating period · weight class could not be normalized reliably

Lion Cub Jiu Jitsu Competition 5
≤ 34 kg · Counts as a competition event
Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
  • Registered weight class: -34 kg
  • Source competition limit: -34 kg

5 matches in the rating period

'The Future League 7' by VERSUS
Does not count
-30&-34kg / 8&9yr / White&Grey
  • Registered weight class: -30&-34kg / 8&9yr / White&Grey
  • Source competition limit: -30&-34kg / 8&9yr / White&Grey

3 matches in the rating period · weight class could not be normalized reliably

Gelders Open BJJ
≤ 38 kg · Counts as a competition event
Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
  • Registered weight class: -38 kg
  • Source competition limit: -38 kg

2 matches in the rating period

Classification evidence

Why Grey?

This outcome uses the belt category of every rating-eligible match from 2025-09-01 through 2026-08-31. The most-fought category is selected; the newest evidence breaks a tie.

Evidence outcome

  • grey 11 matches in the rating period Selected outcome
  • white 2 matches in the rating period

Registrations and outcomes

International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
grey · Counts as a match
Kids GI / 10 - 12 years / White & Grey / -34 kg
  • Source belt category: grey

3 matches in the rating period

Lion Cub Jiu Jitsu Competition 5
grey · Counts as a match
Boys GI / 9 years old (DAY 2: Sunday) / Grey belt / -34 kg
  • Source belt category: grey

5 matches in the rating period

'The Future League 7' by VERSUS
grey · Counts as a match
-30&-34kg / 8&9yr / White&Grey
  • Source belt category: grey

3 matches in the rating period

Gelders Open BJJ
white · Counts as a match
Kids / 8 - 9 years boys / White & Grey / -34 & -38 kg
  • Source belt category: white

2 matches in the rating period