Gemini 3.1 Flash Lite is Round 02's quiet upset. It sits at #4 on multi-turn ELO at 1560 — within striking distance of Sonnet 4.5 (1550) and ahead of GPT-4.1 (1552) — at $0.18 per million tokens. That's 43× cheaper than Sonnet, 24× cheaper than GPT-4.1, and tied with DeepSeek v4 Flash for the lowest price in the pool. The catch is generation speed: 153 tokens/sec, which sounds fast but masks a higher fatal-flaw rate (0.17 per session is decent, but 8.0 majors is mid-pack). The 1M-token context window is preserved from the Pro sibling at a fraction of the price.
▌ Section 03 · At a Glance
Cross-test position
Gemini 3.1 Flash Lite holds #1 in Cost · Latency and #3 in Multi-Turn. Sits at #16 on Adversarial, the caveat to watch.
Composite
13
Arena ELO
n/a
Multi-Turn
3
Rubric
14
Adversarial
16
Cost · Latency
1
▌ Section 04 · Strength & Weakness
Where it shines. Where it stumbles.
▲ Strength
#4 multi-turn ELO at $0.18/1M — the best price-to-rank in the pool. 1M-token context window, fastest generation among top-5 finalists.
▼ Weakness
Avg failure rank of 12.25 across the 20-model pool puts adversarial reliability mid-pack. Flaw-hunter mean of 34.2 sits below the Sonnet/Opus tier.
▌ Section 05 · Failure Modes
Per-axis breakdown.
Six adversarial probes per session, twenty sessions per model, judged by Sonnet 4 against a fixed rubric. Further right = the model handled the failure mode better. Each axis is drawn as a band on the rubric’s 1 to 5 scale, not a number: judges disagree by about 0.3 at the model level, so overlapping bands are a tie. The right column is the rank within the rp-bench pool.
▌ Coverage: 4/6F3 · Lore · F8 · Momentum not yet run on this model. Upstream rolls these out incrementally as new models join the pool.
F1 · Agency
Doesn't write your character's actions
15
#14
F2 · POV / Tense
Holds 2nd-person, present-tense narration
15
#9
F3 · Lore
not yet run on this model
n/a
F8 · Momentum
not yet run on this model
n/a
F12 · Instruction Drift
Keeps to the system prompt
15
#13
F13 · Context Attention
Holds character cards 50+ turns deep
15
#15
“Sonnet-tier multi-turn ELO at 1/43rd the price. Round 02's biggest value.”
Round 02 verdict · Best price-to-rank
▌ Section 06 · Subjective Dimensions
Engagement · Voice · Collaboration.
All three dimensions scored 1 to 5 by the Sonnet 4 LLM judge across twenty 12-turn multi-turn sessions. The same battery feeds the failure-mode rubric above; these are the subjective half of that judgment, drawn as bands with no number for the same reason.
Engagement
15
Tone Consistency
15
Collaboration
15
▌ Section 07 · Behavioral Metrics
How it writes.
Quantitative signals from the same 20 multi-turn sessions, compared against the population mean across all 11 models.
Avg words / turn
264↓
pop avg 265 · -0%
Unique-word ratio
0.644↓
pop avg 0.657 · -2%
Repetition score
0.049↑
pop avg 0.048 · +2%
▌ Section 08 · Flaw Hunter
Adversarial probe score.
Score of 100 minus deductions across 22 fail-mode flag types on adversarial 12-turn sessions. Further right = fewer flaws caught. Drawn as a band, not a number: about ten points either way is rater noise, so bands that overlap are tied.
▌ Craft band
-20100
From the Round 01/02 flaw-hunter pool. The current card carries the newer single-rater band.
Best- and worst-rated sample responses ship with the raw-vote endpoint in Round 02. When that lands, this section will surface the model’s highest- and lowest-scoring blind-arena turns side by side, scored on the same rubric the leaderboard uses.
▌ Round 01 verdict
Flash Lite is the value play if you trust Round 02 voters. The price-to-multi-turn-ELO ratio is uncontested at this scale, and the 1M context window means it doesn't lose to its Pro sibling on the only axis Pro is good at. The reliability numbers are mid-pack — if your product needs strict character control, pay up for Sonnet. For everything else, this is the leading "ship Round 03 cheaply" candidate.