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Mees Kalkman

Delta Jiu-Jitsu

W–L
5–0
Won and lost rating-eligible matches in the past 12 months.
Gi
-
Rating based on Gi matches in the past 12 months.
No-Gi
1,399
Rating based on No-Gi matches in the past 12 months.
Current form
5–0
Results from the ten most recent rating-eligible matches.
Opponents
5
Unique opponents faced in rating-eligible matches in the past 12 months.

Indexed career

Matches

7
Indexed competition matches
Date Opponent Result Event Division
2026-06-28 Kyrylo Cherpita
Win
All Stars BJJ Netherlands No-Gi Juniornogi / Beginner / Teen 2 / 70kg or less / Male
2026-06-28 Matvejs Jupatovs
Win
All Stars BJJ Netherlands No-Gi Juniornogi / Beginner / Teen 2 / 70kg or less / Male
2026-03-28 Brandon Peroti
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI No-Gi · Kids No-GI / 13 - 15 years boys / Grey / -65 kg
2026-03-28 Yahya Develioglu
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI No-Gi · Kids No-GI / 13 - 15 years boys / Grey / -65 kg
2026-03-28 Ibrahim El Makhloufi
Win
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI No-Gi · Kids No-GI / 13 - 15 years boys / Grey / -65 kg
2025-03-01 Rafael Rekondie
Loss
Kaizen League Amsterdam Gi and No-Gi No-Gi · Kids No-gi / Boys 13-15 years / White / -55,00 kg
2025-03-01 Rafael Rekondie
Loss
Kaizen League Amsterdam Gi and No-Gi No-Gi · Kids No-gi / Boys 13-15 years / White / -55,00 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 -1 Rating 1,399

Rating-period composition

Rating matches
5 0
Record
5–0 Previous month 5–0
Opponents
5 0
Events
2 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 +12 Rating 1,400

Rating-period composition

Rating matches
5 0
Record
5–0 Previous month 5–0
Opponents
5 0
Events
2 0

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

June 2026 2 new matches Change +65 Rating 1,388

Rating-period composition

Rating matches
5 +2
Record
5–0 Previous month 3–0
Opponents
5 +2
Events
2 +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
June 28, 2026 Kyrylo Cherpita
All Stars BJJ Netherlands Juniornogi / Beginner / Teen 2 / 70kg or less / Male
Method Points 04:00 0–0
Marginal influence +29
Win
June 28, 2026 Matvejs Jupatovs
All Stars BJJ Netherlands Juniornogi / Beginner / Teen 2 / 70kg or less / Male
Method Points 04:00 0–0
Marginal influence +23
May 2026 No new matches Change 0 Rating 1,323

Rating-period composition

Rating matches
3 0
Record
3–0 Previous month 3–0
Opponents
3 0
Events
1 0

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

April 2026 No new matches Change -2 Rating 1,323

Rating-period composition

Rating matches
3 0
Record
3–0 Previous month 3–0
Opponents
3 0
Events
1 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 · 2 left period Change +196 Rating 1,325

Rating-period composition

Rating matches
3 +1
Record
3–0 Previous month 0–2
Opponents
3 +2
Events
1 0

2 older matches left the 12-month period: 0 won and 2 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.
Win
March 28, 2026 Brandon Peroti
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids No-GI / 13 - 15 years boys / Grey / -65 kg
Method Submission 00:59 0–0
Marginal influence +17
Win
March 28, 2026 Yahya Develioglu
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids No-GI / 13 - 15 years boys / Grey / -65 kg
Method Points 04:00 2–2
Marginal influence +26
Win
March 28, 2026 Ibrahim El Makhloufi
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI Kids No-GI / 13 - 15 years boys / Grey / -65 kg
Method Submission 00:28 0–0
Marginal influence +11
February 2026 No new matches Change 0 Rating 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 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 0 Rating 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 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 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 0

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

November 2025 No new matches Change 0 Rating 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 0

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

October 2025 No new matches Change 0 Rating 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 0

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

September 2025 No new matches Change 0 Rating 1,129

Rating-period composition

Rating matches
2 0
Record
0–2 Previous month 0–2
Opponents
1 0
Events
1 0

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

Relevant matches
4
Official ranking percentile
Top 28%
Performance
-

4 weighted matches against 5 different opponents across 2 events

Weighted win rate
-
Expected win rate
-
Average opponent rating
1,280
Repeated-opponent share
0.0%
Network connectivity
87.6%

Classification evidence

Why U16?

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

  • U16 3 event votes Selected outcome

Registrations and outcomes

All Stars BJJ Netherlands
U16 · Counts
Unfortunately this absolute won’t be running due to a lack of athletes registered
  • Competition age 15
Juniornogi / Beginner / Teen 2 / 70kg or less / Male
  • Competition age 15
  • Registered age: u16
  • Source category: u16
GrappleCity: Rotterdam Summer Open
U16 · Counts
Teens NoGi / Grey / 14-15 years / -65kg / Boy
  • Competition age 15
  • Registered age: u16
  • Source category: u16
International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
U16 · Counts
Kids No-GI / 13 - 15 years boys / Grey / -65 kg
  • Competition age 15
  • Registered age: u16
  • Source category: u16
2025 AGF Amsterdam Open
Does not count
No Gi Kids Challenger / Boys / White Challenger / Middle III (Up to 65.80 kg)
  • Competition age 14
  • Registered age: u16
  • Source category: u16

Classification evidence

Why ≤ 65 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

  • ≤ 65 kg 1 competition event Selected outcome

Registrations and outcomes

All Stars BJJ Netherlands
Does not count
Unfortunately this absolute won’t be running due to a lack of athletes registered

No matches in the rating period · no valid weight evidence

All Stars BJJ Netherlands
Does not count
Juniornogi / Beginner / Teen 2 / 70kg or less / Male

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

GrappleCity: Rotterdam Summer Open
Does not count
Teens NoGi / Grey / 14-15 years / -65kg / Boy
  • Registered weight class: -65kg
  • Source competition limit: -65kg

No matches in the rating period · no valid weight evidence

International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
≤ 65 kg · Counts as a competition event
Kids No-GI / 13 - 15 years boys / Grey / -65 kg
  • Registered weight class: -65 kg
  • Source competition limit: -65 kg

3 matches in the rating period

2025 AGF Amsterdam Open
Does not count
No Gi Kids Challenger / Boys / White Challenger / Middle III (Up to 65.80 kg)
  • Registered weight class: Middle III (Up to 65.80 kg)
  • Source competition limit: Middle III (Up to 65.80 kg)

No matches in the rating period · no valid weight evidence

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 3 matches in the rating period Selected outcome

Registrations and outcomes

International Veluwe Open Jiu Jitsu Championship 2026 GI & NO-GI
grey · Counts as a match
Kids No-GI / 13 - 15 years boys / Grey / -65 kg
  • Source belt category: grey

3 matches in the rating period