Two related questions about how applicants and streams find each other.
(1) Are accepted applicants matching with their top choice? Each Stage-3 applicant submits a ranked preference list of streams. For the 108 applicants who accepted an offer, we can ask: was the offering stream their #1 pick, #2, #5? If most matches happen near the top of the preference list, the pref-rank system is doing its job. If they happen low or off-list, that suggests applicants are flexible or that matching happens through paths the preference list doesn't capture.
(2) Are applicants good at predicting which streams will pick them? At Stage 1, applicants optionally indicate which streams they're interested in. At Stage 3, they actually apply to streams. Some Stage-3 applications go to streams the applicant didn't flag at Stage 1 — 'added' streams. If those added streams reliably rank the applicant, that's evidence applicants and streams find each other even without explicit Stage-1 stream selection. That would support making Stage-1 stream questions optional / low-friction for 11.0.
MATS (Machine Alignment, Transparency & Security) is an AI safety research fellowship that places ~120 fellows with ~100 mentors per cohort. Cohort 10.0 ran in summer 2026 and was the first cohort with a centralized application review instead of decentralized stream-specific review. This analysis is part of a broader effort to evaluate the 10.0 process and inform the design of 11.0 (autumn 2026).
The 10.0 pipeline in brief. ~2,200 people applied. Each applicant went through three stages:
For the empirical track, the composite formula is 0.50·RS + 0.35·TE + 0.15·SS, where TE = 0.50·MLE + 0.30·SWE + 0.20·Math. A "relevance multiplier" (Direct=1.0 / Adjacent=0.85 / Distant=0.60) is applied to Research Skills based on how the applicant's experience matches the streams they applied to.
Outcome definitions used throughout these analyses:
is_ranked (primary outcome) — applicant was ranked by ≥1 stream. This is the cleanest signal of "the selection process picked this person." Not the same as "received an offer" — offer count is bounded by cohort size (~120), but rank count reflects quality independently of capacity.is_invited_to_worktest (secondary outcome) — applicant was engaged by ≥1 stream in any way: invited to a work test, invited to an interview, ranked, or sent the Megastream takehome. Strict superset of is_ranked. One level above is_ranked in the funnel.passed_mentors_bar — applicant was offered or waitlisted. In 10.0, this equals is_ranked exactly (every ranked person got either an offer or a waitlist slot).Of 108 committers (offered + accepted), 90 had their committed stream appear in their own preference list. The distribution:
| Preference rank of committed stream | Committers |
|---|---|
| 1 | 40 (37%) |
| 2 | 21 (19%) |
| 3 | 5 (5%) |
| 4+ | 24 (22%) |
| (not in pref list) | 18 (17%) |
40/108 (37%) committed to their #1 preference. 66/108 (61%) committed to a top-3 preference. The remainder either matched with a lower-preference stream or with a stream not in their preference list at all (often because they didn't submit a preference list).
Of 1,059 Stage-3 applicants:
A meaningful fraction of applicants ended up applying — and being ranked — by streams they didn't pre-flag at Stage 1. This is partly an artifact of optional Stage-1 selection: of the Stage-3 applicants on Empirical/P&S/TG-only tracks, 52 of 538 (10%) didn't make any Stage-1 stream selections at all. For these applicants, every Stage-3 application is an "added" stream by definition.
Sample. Canonical 10.0 sample. Q1 uses the 108 applicants with a non-null [offers] Accepted stream (offered + accepted). Q2 uses the 1,059 Stage-3 applicants.
Outcome variable(s). Q1: position of committed stream in applicant's [stage-3-stream] Stream ranking list (1 = top preference). Q2: did any 'added at Stage 3' stream end up ranking the applicant?
Predictor fields. Descriptive.
Filters applied. Canonical dedup. No further exclusions.
Missing-data handling. Q1: applicants without a preference list (n=18) shown in '(not in pref list)' bucket. Q2: empty Stage-1 stream sets treated as such (producing maximal 'added at S3'), which is a UI artifact noted in the caveats.
Key assumptions / caveats.