swimMackenzie O'Brien
Personal records
| Event | Course | Best | Cut | Date | Meet |
|---|---|---|---|---|---|
| 50 Freestyle | SCY | 30.87 | BB+0.38s to A·+6.08s to Sectionals | 2026-03-01 | 2026 Cherry Blossom Champsvenue |
| 100 Freestyle | SCY | 1:13.92 | B+1.73s to BB·+20.83s to Sectionals | 2025-12-12 | 2025 Katie Ledecky Invitationalvenue |
| 200 Freestyle | SCY | 2:41.59 | B+4.50s to BB·+46.60s to Sectionals | 2026-03-01 | 2026 Cherry Blossom Champsvenue |
| 50 Backstroke | SCY | 37.69 | BB+2.90s to A·+11.40s to Futures | 2026-02-28 | 2026 Cherry Blossom Champsvenue |
| 50 Breaststroke | SCY | 37.22 | AA+1.43s to AAA·+7.43s to Futures | 2026-03-01 | 2026 Cherry Blossom Champsvenue |
| 100 Breaststroke | SCY | 1:21.86 | A+0.07s to AA·+13.67s to Sectionals | 2026-03-14 | 2026 PV SC 14 & Under Championships - copiedvenue |
| 200 Breaststroke | SCY | 3:08.84 | BB+4.25s to A·+39.45s to Sectionals | 2025-10-11 | 2025 PV October Open - Fairlandvenue |
| 50 Butterfly | SCY | 37.51 | B+1.42s to BB·+11.82s to Futures | 2026-01-18 | PVS January Open 2026 - Fairlandvenue |
| 100 Butterfly | SCY | 1:34.74 | +3.95s to B·+36.25s to Sectionals | 2026-01-17 | PVS January Open 2026 - Fairlandvenue |
| 100 Individual Medley | SCY | 1:18.17 | BB+2.18s to A | 2026-03-14 | 2026 PV SC 14 & Under Championships - copiedvenue |
| 200 Individual Medley | SCY | 2:59.20 | B+0.21s to BB·+48.51s to Sectionals | 2026-02-27 | 2026 Cherry Blossom Champsvenue |
| 50 Freestyle | LCM | 34.83 | BB+0.04s to A·+6.54s to Sectionals | 2026-04-25 | 2026 PAC Dive into Spring LC Meetvenue |
| 100 Freestyle | LCM | 1:21.76 | BB+5.27s to A·+21.07s to Sectionals | 2026-05-31 | Maryland State LC Championshipvenue |
| 50 Breaststroke | LCM | 42.67 | AA+1.58s to AAA·+7.88s to Futures | 2026-05-31 | Maryland State LC Championshipvenue |
| 100 Breaststroke | LCM | 1:33.78 | AA+3.59s to AAA·+15.89s to Sectionals | 2026-07-18 | PV 2026 LC Age Group Championships - copiedvenue |
| 50 Butterfly | LCM | 41.15 | B+0.66s to BB·+11.66s to Futures | 2026-05-31 | Maryland State LC Championshipvenue |
| 200 Individual Medley | LCM | 3:14.76 | BB+5.67s to A·+46.37s to Sectionals | 2026-05-29 | Maryland State LC Championshipvenue |
Cuts are USA Swimming single-age motivational standards (B → AAAA) at age 11.
National cuts (Sectionals → Nationals) are the current-season meet qualifying times for the swimmer's zone and age group; ✓ marks the hardest cut already achieved.
Fastest relay legs
| Leg | Course | Time | Start | Relay | Date | Meet |
|---|---|---|---|---|---|---|
| 50 Freestyle | SCY | 31.71 | flat | 200 Free Relay | 2026-03-15 | 2026 PV SC 14 & Under Championships - copied |
| 50 Freestyle | SCY | 31.45 | flying | 200 Free Relay (leg 4) | 2026-03-01 | 2026 Cherry Blossom Champs |
| 100 Freestyle | SCY | 1:16.69 | flying | 400 Free Relay (leg 2) | 2025-12-13 | 2025 Katie Ledecky Invitational |
| 50 Breaststroke | SCY | 39.14 | flying | 200 Medley Relay (leg 2) | 2026-03-14 | 2026 PV SC 14 & Under Championships - copied |
| 50 Freestyle | LCM | 36.25 | flat | 200 Free Relay | 2026-05-31 | Maryland State LC Championship |
| 50 Breaststroke | LCM | 43.76 | flying | 200 Medley Relay (leg 2) | 2026-05-30 | Maryland State LC Championship |
Reconstructed from relay split marks. Flat = lead-off (comparable to individual times); flying starts run ~0.5–0.7s fast and are not PRs.
IMX / IMR
IMX 11-12 · SCY
1398 points (3/5 events — incomplete)
| Event | Time | Points |
|---|---|---|
| 100 BR SCY | 1:21.86 | 666 |
| 100 FL SCY | 1:34.74 | 277 |
| 200 IM SCY | 2:59.20 | 455 |
| 500 FR SCY | — | 0 |
| 100 BK SCY | — | 0 |
IMR 11-12 · SCY
2531 points (5/5 events)
| Event | Time | Points |
|---|---|---|
| 200 FR SCY | 2:41.59 | 429 |
| 50 BK SCY | 37.69 | 459 |
| 50 BR SCY | 37.22 | 696 |
| 50 FL SCY | 37.51 | 402 |
| 100 IM SCY | 1:18.17 | 545 |
Scored against AAAA motivational base times: ordering is exact, absolute points run ~25% above the official USA Swimming scale.
PR splits
50 Freestyle SCY 30.87
100 Freestyle SCY 1:13.92
Front half 34.27s · back half 39.65s
200 Freestyle SCY 2:41.59
Front half 75.13s · back half 86.46s
100 Breaststroke SCY 1:21.86
Front half 39.73s · back half 42.13s
200 Breaststroke SCY 3:08.84
Front half 90.05s · back half 98.79s
100 Butterfly SCY 1:34.74
Front half 43.66s · back half 51.08s
100 Individual Medley SCY 1:18.17
Front half 36.33s · back half 41.84s
200 Individual Medley SCY 2:59.20
Front half 82.15s · back half 97.05s
100 Freestyle LCM 1:21.76
Front half 38.19s · back half 43.57s
100 Breaststroke LCM 1:33.78
Front half 42.91s · back half 50.87s
200 Individual Medley LCM 3:14.76
Front half 96.14s · back half 98.62s
Swim history
Every recorded swim, newest first
| Date | Event | Course | Time | Age | Round | Meet |
|---|
Individual swims with a recorded date and time — including disqualifications — plus reconstructed relay legs (marked). Assembled in the browser from this page’s data.
Progression
Faster times are higher. One card per event, all courses & history.