No. 20-1530 · argued February 28, 2022
West Virginia, et al., Petitioners v. Environmental Protection Agency, et al.
Post-argument lean
From the argument alone, before the decision
70%
chance the petitioner prevails, from how the bench divided its words
Petitioner won Judgment REVERSED and case REMANDED. Roberts, C. J., delivered the opinion of the Court...
The Justices’ words, by the side they were spoken to
52%
48%
To the petitioner · 4,177 words, 114 turns121 turns, 3,925 words · to the respondent
The bench spoke 1.1× as many words to the petitioner as to the other side. Since OT2017 the side that draws more of the bench’s words has tended to lose, so this argument reads close to the usual 70% petitioner win rate. The lean pointed the right way.
Each Justice’s questioning
Lean beside the vote each Justice cast
| Justice | Words to the petitioner ◂ │ ▸ to the respondent | Lean to petitioner | Voted for |
|---|---|---|---|
| Roberts, C.J. | 77%+7 | Petitioner ✓ | |
| Thomas | 51%-9 | Petitioner ✓ | |
| Breyer | 60%-4 | Respondent ✗ | |
| Alito | 90%+29 | Petitioner ✓ | |
| Sotomayor | 58%+0 | Respondent ✗ | |
| Kagan | 54%-7 | Respondent ✗ | |
| Gorsuch | 41%-25 | Petitioner ✗ | |
| Kavanaugh | 82%+13 | Petitioner ✓ | |
| Barrett | 46%-22 | Petitioner ✗ |
A Justice’s lean is the chance they vote for the petitioner, from their own word split and the whole bench’s; the small figure is the change from their usual petitioner rate. Click a row to pick out that Justice in the transcript.
Listen and read
427 turns
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The Court’s recording · each line timed to the audio
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From the Court’s official transcript.
October Term 2021, lean against result
Each dot an argument; click one to open it
18 of 22
leaned 75% or more to the petitioner, and the petitioner won
0 of 3
leaned toward the respondent, and the respondent won
45 of 59
decided cases where the lean pointed the right way (always picking the petitioner: 48)
About this page. Built from the Court’s own transcript and recording.
- The lean. Backtested leave-one-Term-out on 511 decided arguments (OT2017–OT2025): 72% of outcomes called right against 70.5% for “the petitioner always wins”, with forecast error (Brier score) 0.197 against 0.209. It refines a strong base rate more than it flips calls. Each Justice’s lean: 67.5% of 4,408 votes against 63.4% for their usual rate.
- Words, not questions. Every Justice turn in an advocate’s time counts toward that advocate’s side; amicus time counts for neither. Counting turns adds nothing once words are counted, and the raw rule “more questions loses” does worse than the base rate, because petitioners argue first and have rebuttal.
- Timing. Each line is timed to the recording: speech recognition matched the Court’s audio to its transcript, and its own text is used for nothing but the clock. Click a line to hear it.
- Method and findings: docs/argument-transcripts.md.