The Girls 17-18 LCM record book reads like a who's who of American swimming's recent past. Katie Ledecky holds the entire distance free lineup. Regan Smith owns both the 100 and 200 backstroke. Lilly King's 200 breast from 2015 is on the board. Alex Walsh, Torri Huske, Claire Curzan, Lydia Jacoby — the list of record holders reflects the depth of talent this age group has produced over the last decade.

Against those marks, this winter's 17-18 field is led by Charlotte Crush, who appears across eight events and projects near or into several records. Kayla Han owns the distance free picture, and Molly Sweeney leads one of the most compelling breaststroke events in the dataset.

A standing note on backstroke: classical SCY-to-LCM conversion produces aggressive results in backstroke at this age. Projections that appear to clip records should be read alongside last-season LCM references, which are the more reliable measure of where swimmers actually stand in long course competition.

Sprint Freestyle

50 Freestyle — NAG: 24.43 | Claire Curzan (2022)

Charlotte Crush (18) leads at 21.98 SCY (25.20 projected, +3.15%), with a last-season LCM reference of 26.08 — 1.65 seconds above the record in actual competition. Riley Anderson (18) follows at 22.07 SCY (25.30 projected), with a more advanced last-season LCM reference of 25.65 (+4.99%) — the best real 50 free LCM time in this group. Zoe Smith (18) rounds out the group at 22.18 SCY (25.42 projected), with a 26.33 last-season LCM reference.

In the 50 free at 17-18, 1+ seconds is a real gap. Anderson's 25.65 last-season LCM time leads the field in actual competition. The record is protected, but both Anderson and Crush have development trajectories worth tracking.

100 Freestyle — NAG: 53.25 | Simone Manuel (2014)

Manuel's 100 free has been on the books since 2014 and the current field isn't projecting close enough to change that this summer. Charlotte Crush leads at 47.72 SCY (54.57 projected, +2.48%), with a last-season LCM reference of 55.54 — 2.29 seconds above the record in actual competition. Zoe Smith follows at 47.80 SCY (54.66 projected), with a last-season LCM reference of 56.49. Molly Workman (18) rounds out the group at 48.31 SCY (55.22 projected), with a 55.92 last-season LCM reference.

The record has clear real-world protection. Crush leads the field in both projection and last-season LCM performance — her 55.54 is the most advanced real 100 free time in this group, still 2.29 seconds short of Manuel's mark.

Distance Freestyle

200 Freestyle — NAG: 1:54.43 | Katie Ledecky (2016)

Ledecky's 200 free has held since 2016 and the current field projects 4–5% above it. Charlotte Crush leads at 1:44.67 SCY (1:59.38 projected, +4.33%), with a last-season LCM reference of 2:01.19 — nearly 7 seconds above the record in actual competition. Elizabeth Eichbrecht (18) and Kayla Han (18) follow in the 1:59.81–2:00.16 projection range, with Han's last-season LCM reference of 2:00.25 the most advanced real 200 free time in this group — just under the 2:00 barrier.

Han's 2:00.25 last-season LCM time leads the field in real performance, and her continued push under 2:00 LCM is the internal story in this event. The record itself remains safely protected.

400 Freestyle — NAG: 3:58.37 | Katie Ledecky (2014)

Kayla Han leads at 4:38.28 SCY (4:08.36 projected, +4.19%), with a last-season LCM reference of 4:10.38 — 12 seconds above the record in actual competition, but the most advanced real 400 free LCM time in this group. Sydney Schoeck (18) follows at 4:08.01 projected, with a last-season LCM reference of 4:15.99. Elizabeth Eichbrecht rounds out the group at 4:11.27 projected, with a 4:15.15 last-season LCM reference.

Han's 4:10.38 last-season LCM time leads the field. The record has 12+ seconds of real-world protection — Ledecky's distance marks are well-guarded at every level.

800 Freestyle — NAG: 8:06.68 | Katie Ledecky (2016)

Kayla Han leads at 8:29.67 projected (+4.72%), with a last-season LCM reference of 8:35.91 — over 29 seconds above the record in real competition. Sydney Schoeck follows at 8:30.77 projected, with a last-season LCM reference of 8:41.91. Elizabeth Eichbrecht rounds out the group at 8:36.78 projected, with an 8:48.54 last-season LCM reference.

Han's 8:35 last-season LCM time leads the field. Ledecky's 2016 records at distance are among the most protected marks in age group history — the real-world gap confirms that.

1500 Freestyle — NAG: 15:25.48 | Katie Ledecky (2015)

All three candidates project and swim well above Ledecky's 1500 record. Sydney Schoeck leads at 16:10.80 projected, with a last-season LCM reference of 16:28.74 — over a minute above the record in real competition. Kayla Han follows at 16:17.09 projected, with a 16:28.92 last-season LCM reference. Paige Downey (18) rounds out the group at 16:23.22 projected, with a 16:22.67 last-season LCM reference — her real performance is actually slightly ahead of her own projection.

Ledecky's distance records at 17-18 are in a category of their own. The field is competitive within itself — Schoeck and Han trading mid-16s — but the records are not under realistic pressure.

Backstroke

Classical backstroke conversion note: all three 50BK and 100BK projections clip the records on paper. Last-season LCM references — which are 3–8% above the records — are the more reliable guide to where this field actually stands.

50 Backstroke — NAG: 27.43 | Leah Shackley (2025)

A 2025 record with maximum recency protection. All three candidates project under it on classical conversion — Alyssa Sagle (18) at 26.93 (-1.82%), Charlotte Crush at 27.08 (-1.28%), Brynn Lavigueur (18) at 27.42 (-0.04%). Last-season LCM references of 28.35, 28.47, and 28.37 put the real picture in focus: all three were roughly 0.92–1.04 seconds above the record in actual competition last summer.

The projections here reflect SCY speed, not current LCM form. Last-season LCM references in the 28.35–28.47 range are the honest baseline — all within about 1 second of a mark set just last year, which is genuinely close but not a present threat given its recency.

100 Backstroke — NAG: 57.57 | Regan Smith (2019)

Charlotte Crush projects to 56.82 (-1.3%) — under the record on paper — with a last-season LCM reference of 59.30 (+3.01%). That 2.48-second gap between her real performance and Smith's record is the honest measure. Alyssa Sagle projects to 57.32 (-0.43%), with a last-season LCM reference of 1:00.64 — a larger real gap. Eva Rottink (18) is third at 58.91 projected (+1.34%), with a 1:02.17 last-season LCM reference.

Crush's 59.30 last-season LCM time is the most developed real backstroke reference in this group — 1.73 seconds above Smith's record in actual competition. That's a real gap in the 100 back at this level, though her development arc makes this one worth monitoring.

200 Backstroke — NAG: 2:03.35 | Regan Smith (2019)

The 200 back is the most compelling backstroke event in the girls dataset — and one where the projection and real reference are closer than the shorter backstroke events. Charlotte Crush projects to 2:03.66 (+0.25%), just 0.31 seconds above Smith's record on paper. Her last-season LCM reference of 2:07.05 (+3.0%) puts her 3.70 seconds above the record in actual competition — a real gap, but meaningfully smaller than in the 50 and 100 back. Alyssa Sagle follows at 2:05.57 projected (+1.8%), with a 2:11.54 last-season LCM reference. Sydney Schoeck rounds out the group at 2:06.15 projected, with a 2:11.81 last-season LCM reference.

Crush's 2:07.05 last-season LCM time is the most advanced real reference in the backstroke field — 3.7 seconds and 3.0% above Smith's record. The projection gap is just 0.25%, but the real reference is the starting point. A meaningful drop in her long course 200 back this summer would put this record in genuine conversation.

Breaststroke

50 Breaststroke — NAG: 30.20 | Lydia Jacoby (2022)

The 50 breast field sits realistically 5–7% above Jacoby's record. Sofia Szymanowski (17) leads at 27.84 SCY (31.90 projected, +5.63%), with a last-season LCM reference of 32.36 (+7.15%). Ella McWhorter (18) is notable: her last-season LCM reference of 32.43 closely matches her own projection of 32.44 — a tight alignment that confirms her long course breaststroke efficiency. Molly Workman follows at 32.44 projected, with a 33.56 last-season LCM reference — further back in real terms.

The record has solid protection in all three cases. McWhorter's projection-to-reference alignment stands out as a sign of genuine LCM consistency, but the 5%+ gap to Jacoby's mark is real in the 50 breast.

100 Breaststroke — NAG: 1:04.95 | Lydia Jacoby (2021)

The 100 breast field projects 4–5% above the record, with last-season LCM references in the 1:08–1:09 range. Molly Sweeney (18) leads at 59.24 SCY (1:07.76 projected, +4.33%), with a last-season LCM reference of 1:08.98 — 4.03 seconds above the record in actual competition. Eliza Wallace (18) follows at 1:07.91 projected, with a 1:09.62 last-season LCM reference. Kayda Geyer (18) rounds out the group at 1:08.17 projected, with a 1:09.28 last-season LCM reference.

Jacoby's record has clear protection at this level. Sweeney leads the field — her 1:08.98 last-season LCM time is the best real 100 breast reference in the group, though still 4 seconds back of the mark.

200 Breaststroke — NAG: 2:24.47 | Lilly King (2015)

This is the most compelling event in the girls 17-18 dataset. Molly Sweeney projects to 2:24.66 — just 0.19 seconds and 0.13% above King's 2015 record on paper. Her last-season LCM reference of 2:28.92 (+3.08%) puts her 4.45 seconds above the record in real competition, which is the honest baseline. Kayda Geyer follows at 2:27.09 projected (+1.81%), with a last-season LCM reference of 2:28.79 — actually ahead of her own projection in real competition, a strong sign of LCM efficiency. Bryce Winzenread (17) rounds out the group at 2:28.13 projected, with a 2:37.57 last-season LCM reference reflecting limited 200 breast LCM experience.

Sweeney's projection is the closest any swimmer in this dataset gets to a standing record on paper — 0.13%. Her 2:28.92 last-season LCM time is the real baseline, and the gap is 3.08%. Geyer's last-season LCM reference actually exceeding her projection makes her the more credible real-world indicator of where this event is heading. If Sweeney closes her LCM gap by 4 seconds this summer, King's 2015 record is in genuine jeopardy.

Butterfly

50 Butterfly — NAG: 25.43 | Claire Curzan (2022)

The 50 fly field sits roughly 5–7% above Curzan's record in real terms — meaningful protection in a sprint event. Mena Boardman (18) stands out on real performance: her last-season LCM reference of 26.23 (+3.15%) is the most advanced real 50 fly time in this group — notably ahead of both her own projection (27.14) and the other candidates' references. Lucy Velte (17) leads on projection at 26.90 (+5.78%), with a last-season LCM reference of 26.84 — closely aligned. Mia Buff (18) follows with no last-season LCM reference available.

Boardman's 26.23 last-season LCM time is the standout real data point — it significantly outpaces her own projection and is the closest any candidate gets to the record in real competition. A 0.8-second gap in the 50 fly is real, but she's the swimmer to watch in this event.

100 Butterfly — NAG: 55.66 | Torri Huske (2021)

Charlotte Crush projects to 56.90 (+2.23%), with a last-season LCM reference of 58.09 — 2.43 seconds above Huske's record in actual competition. Clare Watson (18) and Mena Boardman both project around 58.85, with Boardman's last-season LCM reference of 59.19 (+6.34%) and Watson's 1:00.14 reflecting a larger real gap. Crush leads the field clearly in both projection and real performance.

Crush's 58.09 last-season LCM time leads the field — 2.43 seconds and 4.37% above Huske's record in real competition. Protected for now, but her continued butterfly development is worth noting given her overall profile.

200 Butterfly — NAG: 2:06.10 | Alex Shackell (2024)

A 2024 record with recency protection. Alyce Lehman (18) leads at 1:53.84 SCY (2:09.16 projected, +2.43%), with a last-season LCM reference of 2:10.82 — 4.72 seconds above the record in actual competition. Clare Watson follows at 2:09.66 projected, with a 2:11.83 last-season LCM reference. Taylor Klein (18) rounds out the group at 2:10.22 projected, with a 2:14.21 last-season LCM reference.

Shackell's 2024 record has real protection across both projection and reference measures. Lehman leads the field in actual competition at 2:10.82, still 4.72 seconds back. This event is one to track on a longer horizon.

Individual Medley

200 IM — NAG: 2:09.01 | Alex Walsh (2019)

Charlotte Crush projects to 2:10.71 (+1.32%), with a last-season LCM reference of 2:17.15 — 8.14 seconds and 6.31% above the record in actual competition. That is a large real gap in the 200 IM. Kayla Han is the more grounded candidate: her last-season LCM reference of 2:14.69 (+4.4%) is the most advanced real 200 IM time in this group, and while it still carries a real gap to Walsh's record, it's significantly closer than Crush's real baseline. Lucy Velte (17) rounds out the group at 2:11.62 projected, with a 2:18.14 last-season LCM reference.

Han's 2:14.69 last-season LCM time is the most relevant real reference — 5.68 seconds and 4.4% above Walsh's record in actual competition. Crush's projection is the tightest, but her real gap is more than twice that of Han's. The record is protected; Han leads the field in real terms.

400 IM — NAG: 4:31.41 | Katie Grimes (2023)

Kayla Han projects to 4:36.44 (+1.85%), with a last-season LCM reference of 4:40.58 — 9.17 seconds and 3.38% above Grimes's 2023 record in actual competition. Sydney Schoeck follows at 4:37.48 projected, with a 4:43.20 last-season LCM reference. Emma Cigna (18) rounds out the group at 4:42.89 projected, with a 4:51.18 last-season LCM reference.

Han leads the field in both projection and real performance — her 4:40.58 last-season LCM time is the most relevant real benchmark, within 9 seconds and 3.38% of Grimes's 2023 record. Not an imminent threat, but the most credible real-world pressure on this record in the current field.

Overall Picture

Charlotte Crush (18) is the defining name of the Girls 17-18 dataset — appearing in eight events, with projections that clip or approach records in the backstroke and IM picture. The consistent theme across her profile, however, is a gap between her exceptional SCY performances and her current long course results. Her real LCM gaps in the 100 back (3.01%), 200 IM (6.31%), and 200 free (5.91%) are all meaningfully larger than her projection gaps suggest. The 200 back (3.0% real gap, 0.25% projection) is the event where the two measures are most aligned — and the one where her long course development matters most to watch.

Kayla Han (18) is the most proven long course performer in the dataset. Her last-season LCM references in the 400 free (4:10.38), 200 free (2:00.25), 200 IM (2:14.69), and 400 IM (4:40.58) are the most advanced real-world baselines across those events. She converts consistently between course formats, and her continued push toward the sub-2:00 200 free barrier and sub-4:40 400 IM are the more meaningful milestones to track — ahead of any specific record.

Molly Sweeney (18) carries the most compelling single-event story: her 200 breast projection of 2:24.66 is just 0.13% above King's 2015 record. Her last-season LCM reference of 2:28.92 (3.08% above the record) is the realistic baseline — a 4-second LCM drop in the 200 breast would put a 2015 record in real jeopardy. Mena Boardman's 50 fly last-season LCM reference of 26.23 also stands out — it outpaces her own projection and makes her the most credible real-performance butterfly threat in this field.

All projections use classical SCY-to-LCM conversion. Converted times are estimates only. Backstroke projections in particular can run aggressive with classical conversion — last-season LCM references are the more reliable indicator in those events. Last-season LCM reference times are from the 2024–25 season. Age eligibility based on August 1, 2026 cutoff (swimmer remains 17 or 18 as of 8/1/2026).