swimMackenzie O'Brien
Personal records
| Event | Course | Best | Cut | Date | Meet |
|---|---|---|---|---|---|
| 50 Freestyle | SCY | 30.87 | AA+1.18s to AAA | 2026-03-01 | 2026 Cherry Blossom Champs venue |
| 100 Freestyle | SCY | 1:13.92 | BB+2.43s to A | 2025-12-12 | 2025 Katie Ledecky Invitational venue |
| 200 Freestyle | SCY | 2:41.59 | BB+3.20s to A | 2026-03-01 | 2026 Cherry Blossom Champs venue |
| 50 Backstroke | SCY | 37.69 | A+1.50s to AA | 2026-02-28 | 2026 Cherry Blossom Champs venue |
| 50 Breaststroke | SCY | 37.22 | AAA+0.33s to AAAA | 2026-03-01 | 2026 Cherry Blossom Champs venue |
| 100 Breaststroke | SCY | 1:21.86 | AAA+1.67s to AAAA | 2026-03-14 | 2026 PV SC 14 & Under Championships - copied venue |
| 200 Breaststroke | SCY | 3:08.84 | 2025-10-11 | 2025 PV October Open - Fairland venue | |
| 50 Butterfly | SCY | 37.51 | BB+0.52s to A | 2026-01-18 | PVS January Open 2026 - Fairland venue |
| 100 Butterfly | SCY | 1:34.74 | BB+8.65s to A | 2026-01-17 | PVS January Open 2026 - Fairland venue |
| 100 Individual Medley | SCY | 1:18.17 | AA+2.98s to AAA | 2026-03-14 | 2026 PV SC 14 & Under Championships - copied venue |
| 200 Individual Medley | SCY | 2:59.20 | BB+3.01s to A | 2026-02-27 | 2026 Cherry Blossom Champs venue |
| 50 Freestyle | LCM | 34.83 | AA+1.14s to AAA | 2026-04-25 | 2026 PAC Dive into Spring LC Meet venue |
| 100 Freestyle | LCM | 1:21.76 | A+3.47s to AA | 2026-05-31 | Maryland State LC Championship venue |
| 50 Breaststroke | LCM | 42.67 | AAA+0.58s to AAAA | 2026-05-31 | Maryland State LC Championship venue |
| 100 Breaststroke | LCM | 1:34.95 | AAA+1.86s to AAAA | 2026-05-30 | Maryland State LC Championship venue |
| 50 Butterfly | LCM | 41.15 | A+1.66s to AA | 2026-05-31 | Maryland State LC Championship venue |
| 200 Individual Medley | LCM | 3:14.76 | A+1.27s to AA | 2026-05-29 | Maryland State LC Championship venue |
Cuts are USA Swimming single-age motivational standards (B → AAAA) at age 10.
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 Breaststroke | SCY | 39.14 | flying | 200 Medley Relay (leg 2) | 2026-03-14 | 2026 PV SC 14 & Under Championships - copied |
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 10 & under · SCY
2568 points (4/5 events — incomplete)
| Event | Time | Points |
|---|---|---|
| 200 FR SCY | 2:41.59 | 598 |
| 100 BR SCY | 1:21.86 | 940 |
| 100 FL SCY | 1:34.74 | 418 |
| 200 IM SCY | 2:59.20 | 612 |
| 100 BK SCY | — | 0 |
IMR 10 & under · SCY
3531 points (5/5 events)
| Event | Time | Points |
|---|---|---|
| 100 FR SCY | 1:13.92 | 584 |
| 50 BK SCY | 37.69 | 646 |
| 50 BR SCY | 37.22 | 973 |
| 50 FL SCY | 37.51 | 580 |
| 100 IM SCY | 1:18.17 | 748 |
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 1:34.95
Front half 44.45s · back half 50.50s
200 Individual Medley LCM 3:14.76
Front half 96.14s · back half 98.62s
Progression
Faster times are higher. One card per event, all courses & history.