Tools chosen: polymarket_direct polymarket_related kalshi_related claude_news gdelt_news code_execution wikipedia

Sub-questions (Fermi decomposition)

Planner reasoning

This question hinges on the current top Coding Arena score (no style control), the historical rate at which top scores have climbed, and expected frontier model releases (GPT-5.x/6, Gemini 3.x, Claude, Grok) before end of 2026. The market price is the primary anchor; news and related markets on AI leaderboards provide triangulation, and code execution can extrapolate the score trajectory.

# Current state Polymarket prices this event at 37.5% YES, down sharply from an 81.5% high and a -26.5% 30-day move — signaling real market skepticism about crossing 1560 on the specific "no-style-control Coding" leaderboard, despite third-party blogs citing already-above-1560 scores (which likely reference different leaderboard variants). The resolution source (arena.ai/leaderboard/text/coding-no-style-control) has not been directly queried in this research; all cited scores come from secondary trackers with methodology ambiguity. # Timeline of key events - 2026-05-24 (reported): "Coding" leaderboard snapshot shows claude-opus-4-7-thinking leading at 1567 (propelcode.ai) — but this cites the "Code Arena WebDev" leaderboard, not necessarily the resolution-specified no-style-control Coding tab. - 2026-06-09 (reported): Anthropic launches Claude Fable 5 / Mythos 5 (morphllm.com, benchlm.ai). - Mid-2026 (reported): Claude Opus 4.7 cited as #1 on "Hard Prompts and Coding" with overall Elo ~1420 — a different/lower scale than the 1567-1582 figures (toolcenter.ai), indicating scale inconsistency across trackers. - 2026-07-01/07-12 (reported): Arena.ai undergoes a service restoration and re-baselines scores to count only post-restoration votes — a methodology reset that breaks score continuity (localaimaster.com). - 2026-07-19 (reported): Alibaba previews Qwen3.8, claiming second place behind Claude Fable 5 (siliconangle.com/GDELT). - 2026-07-24 (reported): Claude Opus 5 reaches GA (morphllm.com). - 2026-08-04 (reported): "Fable 5 Laps Field on MirrorCode" — GPT-5.5 coding score reportedly collapses on a benchmark redesign (techtimes.com/GDELT), underscoring volatility/benchmark-design sensitivity of coding scores. - 2026-08 (reported): swfte.com tracker claims Claude Opus 4.8 leads plain Coding Arena at ~1582, ahead of Opus 4.7 at 1567 — unverified against the official style-control-off resolution page. - 2026-08 (reported): A separate "Fullstack Code Arena" (distinct sub-benchmark) shows Claude Opus 5 Max at 1699 and GPT-5.6 Sol at ~1638 — NOT the plain Coding category used for resolution. - Ongoing 2026-08/09: Frontier release cadence continues (Gemini 3.7 Flash, GPT-5.6 tiers, Grok 4.6, DeepSeek V4-Pro) roughly monthly (GDELT/heise.de/memeburn.com). # Event Will any model reach ≥1560 on the arena.ai Text Arena "Coding" leaderboard (style control OFF) by Dec 31, 2026? # Outcomes to forecast Yes / No # Kalshi market anchor No Kalshi-direct price returned in this research batch (kalshi_related found 0 matches). Treat Polymarket as the primary cross-market anchor: **37.5% YES**, down from an 81.5% peak, -26.5% over 30 days, +2% over 7 days, on $93K volume — a meaningful downward repricing suggesting the market believes the threshold has NOT yet been cleanly crossed on the specific resolution page. # Sub-question answers 1. **Current top score / model** — Conflicting: third-party trackers claim 1567–1582 (Claude Opus 4.7/4.8) on "Coding," but these appear to reference WebDev/Hard-Prompts variants, not confirmed to be the exact "coding-no-style-control" page. No direct read of the official resolution URL was obtained. 2. **Trend rate of increase** — Not cleanly quantified; Arena's own blog says top-5 mean score rose from ~1000 (May 2023) to ~1500 (overall Text Arena, Aug 2026), implying long-run gradual drift plus release-driven jumps of ~10-40 pts (claude_news, code_execution model). 3. **Gap to 1560 and time needed** — If current top score is genuinely ~1567+, gap is already closed; if it's closer to 1490-1520 (per Sophon style-control tracker at 1550, or toolcenter's 1420 overall), 10-90 points remain, closable in 1-6 months at typical jump sizes per Monte Carlo model. 4. **Frontier releases expected before Dec 2026** — Confirmed pattern of near-monthly frontier releases (Opus 5, GPT-5.6 tiers, Gemini 3.7, Grok 4.6, DeepSeek V4-Pro, Qwen3.8) through Aug 2026; cadence strongly supports continued step-jumps (GDELT, claude_news). 5. **Methodology changes** — Confirmed: Arena re-baselined scores July 12, 2026 after a July 1 restoration, resetting vote-counting — this breaks trend continuity and adds uncertainty to any "current score" reading (localaimaster.com). 6. **Polymarket price / related markets** — 37.5% YES on this exact market; no related Polymarket or Kalshi markets found for adjacent thresholds/categories to triangulate a distribution. # Key facts (high-confidence, factual) 1. [polymarket_direct] Current Polymarket YES price: 37.5%, down from 81.5% high, -26.5% over 30 days. 2. [localaimaster.com] Arena re-baselined leaderboard scoring on 2026-07-12. 3. [morphllm.com] Claude Opus 5 reached GA 2026-07-24; Opus 4.8 released 2026-05-28. 4. [GDELT/techtimes.com] Benchmark redesign caused a reported GPT-5.5 coding score "collapse" (2026-08-04), showing scores are sensitive to benchmark/methodology changes, not just model capability. 5. [Wikipedia] Arena (formerly LMArena/Chatbot Arena) has documented methodological limitations noted in independent research. # Cross-market signals - Kalshi related: none found. - Polymarket: 37.5% YES, high volatility (31%-81.5% range over 91 days), recent downtrend dominant despite small 7-day uptick. - Sportsbook implied: N/A. # Analyst opinions and speculation - claude_news synthesis argues trajectory "strongly favors crossing 1560... may have already occurred," but this leans on trackers not confirmed to match the exact resolution page/style-control setting. - code_execution Monte Carlo (not grounded in confirmed current score) estimates 70-96% probability range, centered ~85%, but is highly sensitive to unverified starting score assumption (S0). # Directional lean per outcome - **Yes**: Frequent frontier releases (monthly cadence), historical jump sizes (10-40 pts), long-run upward drift, and some trackers claiming score already >1560 all support Yes. - **No**: Polymarket's sharp 30-day decline to 37.5% (from 81.5%) suggests informed traders see the *specific* no-style-control resolution score still below 1560; re-baselining/methodology resets add score-continuity risk; conflicting leaderboard variants (style-control 1550, overall Hard-Prompts 1420) suggest true "coding-no-style-control" score may be lower than optimistic trackers claim. # Gaps / unknowns - No direct read of arena.ai/leaderboard/text/coding-no-style-control obtained — the single most important missing data point. - No Kalshi-direct price captured for this ticker. - Unclear why Polymarket price fell so much if scores are truly already >1560 — possible resolution ambiguity or trader skepticism about tracker accuracy. # Calibration anchors - Polymarket YES price (anchor): 37.5%, recent 30-day decline of -26.5pp. - Monte Carlo base-rate model (unverified inputs): ~70-90% range. - Precedent: rapid, frequent frontier-model releases historically produce periodic 10-40 pt Arena jumps, but methodology resets (as seen July 2026) can offset apparent progress.

1. Both forecasts converge almost mechanically on the Polymarket anchor (37.5%→40%/43%) without independently weighing the Monte Carlo base-rate estimate (70-96%, centered ~85%) — neither explains why they discount that model so heavily beyond "unverified S0," despite the brief noting gaps as small as 10-13 points (Sophon-style tracker at ~1550) that historical 10-40pt release jumps could close easily given near-monthly cadence. 2. Neither forecaster grapples with the brief's own flagged puzzle: "Unclear why Polymarket price fell so much if scores are truly already >1560 — possible resolution ambiguity or trader skepticism about tracker accuracy." This is treated as confirming "score is below 1560" rather than as an unresolved anomaly that could equally reflect illiquidity, thin/uninformed trading, or confusion about which leaderboard variant resolves the market. 3. Neither addresses a critical resolution-criteria ambiguity: does "reach 1560 by Dec 31, 2026" require the score to be at ≥1560 at the close date, or does a transient touch (e.g., the May 24 snapshot showing 1567, pre-rebaseline) count as having "reached" it at any point in the period? This materially changes the analysis since the July 12 re-baseline resetting scores downward would be irrelevant if the resolution only requires a one-time crossing. 4. Both forecasts are nearly identical (0.40 vs 0.43) despite supposedly independent reasoning, suggesting anchoring on each other's/the market's number rather than genuinely exploring the wide plausible range implied by conflicting evidence (1420 to 1699 across variants) — a red flag for insufficient dispersion given how uncertain the "current true score" actually is. 5. Neither forecast seriously considers a lower-tail scenario where the re-baseline effectively resets the trend clock, meaning the ~+10-40pt/release cadence may need to compound from a much lower post-reset baseline (~1420-1500 per Hard-Prompts data), making 1560 much harder to reach than a simple "gap of 10-90 points" framing implies — this would argue for a No probability notably higher than ~57-60%. 6. Both treat the Polymarket price as if it were a clean Kalshi-equivalent anchor, but the brief explicitly states no Kalshi price exists and Polymarket volume is only $93K with high volatility (31%-81.5% range over 91 days) — this thin, swingy market may be a much noisier signal than either forecaster's confidence in "anchoring near it" implies.

43% (47% confidence)

Yes: 43% No: 57%

Both forecasts sit close to the Polymarket anchor (37.5%), and the critique's strongest points cut in both directions: the July 12 re-baseline may have reset scores well below 1560 (arguing for No), but a transient pre-reset touch or fast release-driven jumps could still resolve Yes, and the Monte Carlo model suggests upside if the true current score is 1520-1550. The sharp market decline from 81.5% is the most informative signal available — traders likely watching the exact resolution page believe the threshold has not been cleanly crossed post-reset — though thin $93K liquidity means the anchor deserves only moderate weight. With near-monthly frontier releases (Opus 5, GPT-5.6, Gemini 3.7) and roughly four months remaining, a 10-40 point jump closing a plausible 10-60 point gap is realistic but far from assured. I land modestly above the market at 43% Yes, consistent with both forecasts and neither critique direction being decisive.

Total pipeline time: 232.9s