USCF player statistics
Sietsema, Sean Andrew
Official US Chess recordRegular rating
Published rating · Sep 2026 · 10 published updates since Dec 2025
Other formats against Regular
-2 Quick vs Regular
No national baseline for this rating band yet.
How this rating moves
Between consecutive published observations, provisional included.
- Biggest gain
- +31
- Feb 2026 to Mar 2026
- Biggest drop
- -11
- Dec 2025 to Jan 2026
- Longest rise
- 1 update
- +31 from Feb 2026 to Mar 2026
- Current run
- 6 updates
- Unchanged since Mar 2026
- Typical move
- ±5
- Mean absolute change; spread ±11.4
Regular rating in context
United States
18.4%of the comparison population has a lower rating.
15,450 lower · 63 same rating · 68,122 higher
Where this rating sits · United States
83,635 rated members in 50-point bands · median 800–849 · 10,594 within 100 points of 329
300–349: 2,672 members (3.1%) · highlighted band is the player’s · dashed line is the target
19.8% below 350 (16,619 of 83,635; 18.4% below 329)
How these comparisons are calculated
Chess67 calculations from the Sep 2026 monthly rating update, using the same population as the USCF statistics pages: US members classified as active in the published monthly records, excluding lifetime-coded records, provisional ratings included. Ties share a rank; “lower” is strictly lower; national and state groups overlap. The target explorer keeps the population fixed: it is a rating comparison, not a prediction of future rank. This player is outside that comparison population; no membership rank is assigned.
Published ratings by month
P marks a provisional rating; the small figure is the change since the previous published observation.
| Month | Regular | Quick |
|---|---|---|
| Sep 2026 | 329no change | 327no change |
| Aug 2026 | 329no change | 327no change |
| Jul 2026 | 329no change | 327no change |
| Jun 2026 | 329no change | 327no change |
| May 2026 | 329no change | 327no change |
| Apr 2026 | 329no change | 327+1 |
| Mar 2026 | 329+31 | 326+31 |
| Feb 2026 | 298no change | 295-2 |
| Jan 2026 | 298 P-11 · 18 games | 297 P-11 · 18 games |
| Dec 2025 | 309 P15 games | 308 P15 games |