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NL

Sam Hamster

Zerofifty_sport&fights

W–L
8–2
Won and lost rating-eligible matches in the past 12 months.
Gi
1,337
Rating based on Gi matches in the past 12 months.
No-Gi
1,341
Rating based on No-Gi matches in the past 12 months.
Current form
8–2
Results from the ten most recent rating-eligible matches.
Opponents
3
Unique opponents faced in rating-eligible matches in the past 12 months.

Honours

Medals and placements

Gold
4
Silver
4
Bronze
1
Total medals
9
Events with results
6

Full career record

Wins
10
Losses
4
Matches
14
Win rate
71.4%

Ways of winning

Submission
4
Points
6
Decision
0
Disqualification
0

Personal records

Longest winning streak
8
Longest submission streak
2
Longest gold streak
1
Largest recorded points win
6–0

Recent recorded placements

  1. Grappling Industries AMSTERDAM

    NL Event record 2–0

    • Gi Kids / 16 - 17 years (Male) / White / -135 lbs
    • No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -135 lbs

  2. Grappling Industries AMSTERDAM

    NL Event record 4–0

    • Gi Kids / 16 - 17 years (Male) / White / -125 lbs
    • No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs

  4. Grappling Industries AMSTERDAM

    NL Event record 2–2

    • No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
    • Gi Teens / Male / White / 16 - 17 years / -125 lbs

12-month performance profile

How the results were achieved

Past 12 months
Current win streak
8
Unique opponents
3
Distinct events
3

Ways of winning

  • Submission 4 50%
  • Points 4 50%
  • Decision 0 0%
  • Other recorded result 0 0%

Gi versus No-Gi

Gi

Rating
1337
Record
4–1
Win rate
80%
Submission share
25%

No-Gi

Rating
1341
Record
4–1
Win rate
80%
Submission share
75%

Win quality

Grouped by pre-match win probability. This provides context and does not award an extra rating bonus.

As underdog 0–0 Less than 35% expected win probability before the match.
Even match 0–0 Between 35% and 65% expected win probability before the match.
As favourite 0–0 More than 65% expected win probability before the match.

Development

Rating and development

The same published rating, supported by trend, opponent strength and evidence quality.

Current rating
1,417
Change over 90 days
+118
Highest rating in 12 months
1,430
Performance versus expectation
-
Schedule strength
-
Average opponent rating
1,305
Weighted win rate
-
Expected win rate
-
Repeat-opponent share
70%
Effective evidence
6.6
Confidence
73/100

Opponents

Opposition and rivalries

The strongest recorded win, rematches and opponents faced repeatedly.

Rematches 10–4 10–4 across 14 rematches against 4 repeat opponents.

Rivals

Opponent Head-to-head record Matches
Boris Bultje 2–0 2

Scheduled

  1. GrappleCity: Groningen Open 2026

    the Netherlands

    Teens Gi / White / 16-17 years / -60kg / Boy Teens NoGi / White / 16-17 years / -60kg / Boy
    Confirmed

Recent tournaments

  3. GrappleCity: Groningen Winter Open

    November 16, 2025
    No-Gi 0–0

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 · 4 left period Change -18 Rating 1,417

Rating-period composition

Rating matches
10 -4
Record
8–2 Previous month 10–4
Opponents
3 -1
Events
3 -1

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

July 2026 No new matches Change 0 Rating 1,435

Rating-period composition

Rating matches
14 0
Record
10–4 Previous month 10–4
Opponents
4 0
Events
4 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 +5 Rating 1,435

Rating-period composition

Rating matches
14 0
Record
10–4 Previous month 10–4
Opponents
4 0
Events
4 0

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

May 2026 2 new matches Change +35 Rating 1,430

Rating-period composition

Rating matches
14 +2
Record
10–4 Previous month 8–4
Opponents
4 +1
Events
4 +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
May 3, 2026 Boris Bultje
Grappling Industries AMSTERDAM No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -135 lbs
Method Submission 00:57 4–0
Marginal influence +14
Win
May 3, 2026 Boris Bultje
Grappling Industries AMSTERDAM Gi Kids / 16 - 17 years (Male) / White / -135 lbs
Method Points 04:00 6–0
Marginal influence +13
April 2026 No new matches Change +3 Rating 1,395

Rating-period composition

Rating matches
12 0
Record
8–4 Previous month 8–4
Opponents
3 0
Events
3 0

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

March 2026 4 new matches Change +84 Rating 1,392

Rating-period composition

Rating matches
12 +4
Record
8–4 Previous month 4–4
Opponents
3 0
Events
3 +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 1, 2026 Walid Bouabdallah
Grappling Industries AMSTERDAM No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs
Method Submission 02:31 6–2
Marginal influence +10
Win
March 1, 2026 Walid Bouabdallah
Grappling Industries AMSTERDAM No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs
Method Points 04:00 3–2
Marginal influence +10
Win
March 1, 2026 Walid Bouabdallah
Grappling Industries AMSTERDAM Gi Kids / 16 - 17 years (Male) / White / -125 lbs
Method Points 04:00 8–2
Marginal influence +7
Win
March 1, 2026 Walid Bouabdallah
Grappling Industries AMSTERDAM Gi Kids / 16 - 17 years (Male) / White / -125 lbs
Method Submission 02:26 0–0
Marginal influence +7
February 2026 No new matches Change -6 Rating 1,308

Rating-period composition

Rating matches
8 0
Record
4–4 Previous month 4–4
Opponents
3 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.

January 2026 No new matches Change +2 Rating 1,314

Rating-period composition

Rating matches
8 0
Record
4–4 Previous month 4–4
Opponents
3 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.

December 2025 No new matches Change 0 Rating 1,312

Rating-period composition

Rating matches
8 0
Record
4–4 Previous month 4–4
Opponents
3 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.

November 2025 4 new matches Change +31 Rating 1,312

Rating-period composition

Rating matches
8 +4
Record
4–4 Previous month 2–2
Opponents
3 +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
November 2, 2025 Zurubabel Misrak
Grappling Industries AMSTERDAM No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
Method Submission 02:52 5–2
Marginal influence +10
Loss
November 2, 2025 Walid Bouabdallah
Grappling Industries AMSTERDAM No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
Method Submission 00:33 0–0
Marginal influence -14
Win
November 2, 2025 Zurubabel Misrak
Grappling Industries AMSTERDAM Gi Teens / Male / White / 16 - 17 years / -125 lbs
Method Points 04:00 6–4
Marginal influence +17
Loss
November 2, 2025 Walid Bouabdallah
Grappling Industries AMSTERDAM Gi Teens / Male / White / 16 - 17 years / -125 lbs
Method Submission 01:05 0–0
Marginal influence -17
October 2025 No new matches Change 0 Rating 1,281

Rating-period composition

Rating matches
4 0
Record
2–2 Previous month 2–2
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 1,281

Rating-period composition

Rating matches
4 0
Record
2–2 Previous month 2–2
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
6.6
Official ranking percentile
-
Performance
-

6.6 weighted matches against 3 different opponents across 3 events

Weighted win rate
-
Expected win rate
-
Average opponent rating
1,305
Repeated-opponent share
70.0%
Network connectivity
87.6%

Classification evidence

Why U18?

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

  • U18 3 event votes Selected outcome

Registrations and outcomes

Nijmegen Open BJJ 2026
U18 · Counts
Male / White belts 6 + months experience / Adult / -57,5 kg (Rooster)
  • Competition age 17
  • Registered age: u18
  • Source category: u18
Grappling Industries AMSTERDAM
U18 · Counts
Gi Kids / 16 - 17 years (Male) / White / -135 lbs
  • Competition age 17
  • Registered age: u18
  • Source category: u18
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -135 lbs
  • Competition age 17
  • Registered age: u18
  • Source category: u18
2026 AGF Netherlands Championships
Does not count
Gi Juveniles - Adults / Male / Juvenile / White / Rooster (Up to 60 kg)
  • Competition age 17
Grappling Industries AMSTERDAM
U18 · Counts
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs
  • Competition age 17
  • Registered age: u18
  • Source category: u18
Gi Kids / 16 - 17 years (Male) / White / -125 lbs
  • Competition age 17
  • Registered age: u18
  • Source category: u18
GrappleCity: Groningen Winter Open
Does not count
Teens NoGi / White / 16-17 years / -60kg / Boy
  • Competition age 16
  • Registered age: u18
  • Source category: u18
Grappling Industries AMSTERDAM
Does not count
No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
  • Competition age 16
  • Registered age: u18
  • Source category: u18
Gi Teens / Male / White / 16 - 17 years / -125 lbs
  • Competition age 16
  • Registered age: u18
  • Source category: u18
Gelders Open BJJ
Does not count
Kids / 13 - 15 years boys / Yellow / -60 kg
  • Competition age 16
  • Registered age: u16
  • Source category: u16

Classification evidence

Why ≤ 57 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

  • ≤ 57 kg 2 competition events Selected outcome
  • ≤ 61 kg 1 competition event

Registrations and outcomes

Nijmegen Open BJJ 2026
Does not count
Male / White belts 6 + months experience / Adult / -57,5 kg (Rooster)
  • Registered weight class: -57,5 kg (Rooster)
  • Source competition limit: -57,5 kg (Rooster)

No matches in the rating period · no valid weight evidence

Grappling Industries AMSTERDAM
≤ 61 kg · Counts as a competition event
Gi Kids / 16 - 17 years (Male) / White / -135 lbs
  • Registered weight class: -135 lbs
  • Source competition limit: -135 lbs

1 match in the rating period

Grappling Industries AMSTERDAM
≤ 61 kg · Counts as a competition event
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -135 lbs
  • Registered weight class: -135 lbs
  • Source competition limit: -135 lbs

1 match in the rating period

2026 AGF Netherlands Championships
Does not count
Gi Juveniles - Adults / Male / Juvenile / White / Rooster (Up to 60 kg)
  • Registered weight class: Rooster (Up to 60 kg)
  • Source competition limit: Rooster (Up to 60 kg)

No matches in the rating period · no valid weight evidence

Grappling Industries AMSTERDAM
≤ 57 kg · Counts as a competition event
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs
  • Registered weight class: -125 lbs
  • Source competition limit: -125 lbs

2 matches in the rating period

Grappling Industries AMSTERDAM
≤ 57 kg · Counts as a competition event
Gi Kids / 16 - 17 years (Male) / White / -125 lbs
  • Registered weight class: -125 lbs
  • Source competition limit: -125 lbs

2 matches in the rating period

GrappleCity: Groningen Winter Open
Does not count
Teens NoGi / White / 16-17 years / -60kg / Boy
  • Registered weight class: -60kg
  • Source competition limit: -60kg

No matches in the rating period · no valid weight evidence

Grappling Industries AMSTERDAM
≤ 57 kg · Counts as a competition event
No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
  • Registered weight class: -125 lbs
  • Source competition limit: -125 lbs

2 matches in the rating period

Grappling Industries AMSTERDAM
≤ 57 kg · Counts as a competition event
Gi Teens / Male / White / 16 - 17 years / -125 lbs
  • Registered weight class: -125 lbs
  • Source competition limit: -125 lbs

2 matches in the rating period

Gelders Open BJJ
Does not count
Kids / 13 - 15 years boys / Yellow / -60 kg
  • Registered weight class: -60 kg
  • Source competition limit: -60 kg

No matches in the rating period · no valid weight evidence

Classification evidence

Why White?

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

  • white 10 matches in the rating period Selected outcome

Registrations and outcomes

Grappling Industries AMSTERDAM
white · Counts as a match
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -135 lbs
  • Source belt category: white

1 match in the rating period

Grappling Industries AMSTERDAM
white · Counts as a match
Gi Kids / 16 - 17 years (Male) / White / -135 lbs
  • Source belt category: white

1 match in the rating period

Grappling Industries AMSTERDAM
white · Counts as a match
No Gi Kids / 16 - 17 years (Male) / Beginner (White) / -125 lbs
  • Source belt category: white

2 matches in the rating period

Grappling Industries AMSTERDAM
white · Counts as a match
Gi Kids / 16 - 17 years (Male) / White / -125 lbs
  • Source belt category: white

2 matches in the rating period

Grappling Industries AMSTERDAM
white · Counts as a match
No Gi Teens / Male / Beginner (White) / 16 - 17 years / -125 lbs
  • Source belt category: white

2 matches in the rating period

Grappling Industries AMSTERDAM
white · Counts as a match
Gi Teens / Male / White / 16 - 17 years / -125 lbs
  • Source belt category: white

2 matches in the rating period