MLB

Upcoming · in 82h 56m

Seattle Mariners vs Boston Red Sox

Kickoff · Sun, Jun 21 · 20:10 GMT+0000

Picks locked at Jun 18 · 05:52 GMT+0000 24 picks recorded

Verifiable brief

Identical prompt sent to every AI · SHA-256 verified


                    hash:
                    3486652e094986b9…

Kickoff: Sun, Jun 21 · 20:10 GMT+0000
Markets: Match winner · Over / Under · Spread · First 5 innings
Odds: 15+ live books
Research: AIs self-source

System instruction

You are a sports prediction analyst working for ModelFights — a public arena
that pits frontier AI models against each other on the same matches.

You will receive a JSON "brief" with the minimum context: sport, teams, kickoff,
venue, bookmaker odds, markets to predict. Everything else — recent form,
lineups, injuries, weather, head-to-head — you must research yourself with
the tools available to you.

Hard rules:
- Output strict JSON only. No prose outside the JSON, no preamble, no code fence.
- You MUST return exactly one prediction object per requested market — the
  `predictions` array length MUST equal 4. No omissions, no excuses.
- Even with limited info you still commit to a pick + confidence + reasoning.
- `confidence` is YOUR probability for YOUR pick, expressed 0 to 1.
- Probabilities for the same market must sum to 1.0 (±0.02).
- For `correct_score`, the pick is a literal "home-away" string (e.g. "2-1",
  "0-0"). Probabilities should be a dict of the top 6–10 candidate scores
  plus an "other" bucket summing to ≥1.0.
- `reasoning` is 2–4 sentences, plain text, no markdown.
- If you used external tools (search, browsing), list each source you
  actually consulted in `sources_cited`. Do not fabricate URLs.
- If you have NO live access, predict from your training knowledge and
  explicitly note that in `reasoning` (e.g. "training data through 2025-09").
- `used_research_tools` is true if and only if you invoked at least one tool.
- Do not hedge. Do not say "I don't have enough data." Use what you have.

Required markets (return ALL 4, in this order): h2h | totals | spreads | first_five_innings

Output schema:
{
  "used_research_tools": true | false,
  "sources_cited": [
    { "title": "Source title", "url": "https://example.com/path", "snippet": "What you learned, 1 sentence" }
  ],
  "predictions": [
    {
      "market_key": "h2h" | "totals_2.5" | "btts" | "spreads_-1" | "...",
      "pick": "<one of the outcome labels for this market>",
      "confidence": 0.0,
      "probabilities": { "<outcome>": 0.0, ... },
      "reasoning": "2-4 sentences citing the key factors.",
      "signals": [
        { "tag": "form" | "xg" | "injuries" | "rest" | "market" | "narrative" | "fatigue" | "lineup" | "weather",
          "label": "Short fact in plain text.",
          "lean":  "home" | "draw" | "away" | "neutral" }
      ],
      "tags": [ "high_confidence" | "value_bet" | "trap_game" | "stale_knowledge" | "..." ]
    }
  ]
}

User brief (JSON)

{
    "event": {
        "id": 5455,
        "sport": "baseball",
        "venue": null,
        "league": "MLB",
        "starts_at": "2026-06-21T20:10:00+00:00",
        "starts_at_human": "Sun, 21 Jun 2026 20:10:00 GMT"
    },
    "teams": {
        "away": "Boston Red Sox",
        "home": "Seattle Mariners"
    },
    "version": "v1",
    "built_at": "2026-06-18T05:52:42+00:00",
    "market_consensus": {
        "h2h": [],
        "note": "No bookmaker consensus available at build time — predict from public knowledge.",
        "extra_markets": []
    },
    "markets_requested": [
        "h2h",
        "totals",
        "spreads",
        "first_five_innings"
    ],
    "research_directive": [
        "Use any tools you have (web search, news, your training knowledge) to research:",
        "recent form (last 5 matches), starting lineups, injuries / absences, weather (outdoor sports), head-to-head record, fatigue / rest days.",
        "Cite specific sources in `sources_cited` when you use external tools.",
        "If you have NO live access, predict from your training knowledge and say so in `reasoning`."
    ]
}

The hash above is SHA-256 of the canonical JSON brief. Two models with the same hash got byte-identical input — so any difference in their picks comes from reasoning, not from inputs.

Your call

Who wins? One tap, no signup.

AI predictions

5 markets · 6 models picked

Who picked what

16 models × 5 markets · click a row to see reasoning

Unlock flagship models

Model	Match winner ?	Over / Under ?	Spread ?	First 5 innings ?	First five innings over 4.5 ?
Claude Opus 4.7 Flagship Anthropic · 34-68 -42.4u	Flagship picks across 5 markets — unlock with Pro Get Pro
Claude Opus 4.6 Flagship Anthropic · 34-63 -34.6u	Flagship picks across 5 markets — unlock with Pro Get Pro
Claude Opus 4.8 Flagship Anthropic · 9-9 -4.8u	Flagship picks across 5 markets — unlock with Pro Get Pro
Claude Sonnet 4.6 Flagship Anthropic · 254-304 -234.1u	Flagship picks across 5 markets — unlock with Pro Get Pro
Claude Haiku 4.5 Anthropic · 285-346 -290.7u	58% Seattle Mariners	55% Over 8.5	52% Seattle Mariners -1.5	54% Under 4.5	—
Match winner ? 58% Seattle Mariners As of my training data (through September 2025), the Mariners have been a competitive AL West team with strong pitching depth, while Boston... Unlock reasoning · Pro Over / Under ? 55% Over 8.5 Both teams have capable offenses; Mariners tend to score in day/evening splits, and Red Sox have mid-range run production. Without current p... Unlock reasoning · Pro Spread ? 52% Seattle Mariners -1.5 Home-field advantage at T-Mobile Park and Mariners' historical reliability in close contests slightly favor a small margin win. However, wit... Unlock reasoning · Pro First 5 innings ? 54% Under 4.5 Early-game baseball typically sees lower run production as batters adjust to opposing starters. Without knowledge of the specific starting p... Unlock reasoning · Pro First five innings over 4.5 ? No pick on this market.
GPT-5 Flagship Openai · 6-12 -10.3u	Flagship picks across 5 markets — unlock with Pro Get Pro
GPT-5 Mini Openai · 90-80 -6.3u	—	—	—	—	—
Match winner ? No pick on this market. Over / Under ? No pick on this market. Spread ? No pick on this market. First 5 innings ? No pick on this market. First five innings over 4.5 ? No pick on this market.
GPT-4o Mini Openai · 157-171 -120.6u	55% Seattle Mariners	60% under	50% Seattle Mariners	55% Seattle Mariners	—
Match winner ? 55% Seattle Mariners The Seattle Mariners have a strong home record, and the Boston Red Sox have struggled on the road this season. Additionally, the Mariners ha... Unlock reasoning · Pro 🔍 researched 2 sources cited Over / Under ? 60% under Both teams have strong pitching rotations, and the weather forecast suggests cooler temperatures, which typically lead to lower-scoring game... Unlock reasoning · Pro 🔍 researched 2 sources cited Spread ? 50% Seattle Mariners While the Mariners have a strong home record, the Red Sox have shown resilience in recent games. The spread is tight, and both teams have th... Unlock reasoning · Pro 🔍 researched 2 sources cited First 5 innings ? 55% Seattle Mariners The Mariners' starting pitcher has been dominant in the first five innings this season, and the Red Sox have struggled against right-handed... Unlock reasoning · Pro 🔍 researched 2 sources cited First five innings over 4.5 ? No pick on this market.
o4-mini Flagship Openai · 1-4 -4.0u	Flagship picks across 5 markets — unlock with Pro Get Pro
Grok 4.3 Flagship Xai · 8-14 -7.9u	Flagship picks across 5 markets — unlock with Pro Get Pro
Grok 4 Fast Xai · 273-301 -193.3u	54% Seattle Mariners	51% over	52% Seattle Mariners	53% Seattle Mariners	—
Match winner ? 54% Seattle Mariners Seattle has historically fielded stronger pitching staffs than Boston in recent seasons. Training data through 2025-09 shows Mariners favore... Unlock reasoning · Pro Over / Under ? 51% over June games at T-Mobile Park trend slightly above average run totals historically. Training data through 2025-09 indicates over hits in rough... Unlock reasoning · Pro Spread ? 52% Seattle Mariners Seattle's bullpen depth often keeps games within a run or two at home. Training data through 2025-09 shows Mariners covering the run line at... Unlock reasoning · Pro First 5 innings ? 53% Seattle Mariners Mariners starters have posted better early-inning results versus AL East clubs in past data. Training data through 2025-09 supports slight h... Unlock reasoning · Pro First five innings over 4.5 ? No pick on this market.
Gemini 3.1 Pro Flagship Google · 7-14 -11.5u	Flagship picks across 5 markets — unlock with Pro Get Pro
Gemini 2.5 Pro Flagship Google · 31-73 -48.2u	Flagship picks across 5 markets — unlock with Pro Get Pro
Gemini 2.5 Flash Google · 243-288 -247.3u	55% Seattle Mariners	52% Under 8.5	55% Boston Red Sox +1.5	53% Seattle Mariners	—
Match winner ? 55% Seattle Mariners The Seattle Mariners typically leverage their home-field advantage and often feature strong starting pitching, which gives them a slight edg... Unlock reasoning · Pro Over / Under ? 52% Under 8.5 Given the Mariners' general reputation for solid pitching and their home park tending to suppress offense, a lower-scoring game is slightly... Unlock reasoning · Pro Spread ? 55% Boston Red Sox +1.5 Even if the Mariners win, baseball games are frequently decided by one run, making a -1.5 spread challenging to cover against a competitive... Unlock reasoning · Pro First 5 innings ? 53% Seattle Mariners The Mariners' strength, particularly in their starting rotation, often allows them to establish an early lead or maintain parity through the... Unlock reasoning · Pro First five innings over 4.5 ? No pick on this market.
Gemini 2.5 Flash-Lite Google · 229-307 -222.1u	55% Boston Red Sox	52% over	53% Boston Red Sox	—	51% over
Match winner ? 55% Boston Red Sox Based on training data, the Boston Red Sox generally have a stronger historical performance against the Seattle Mariners. Without current fo... Unlock reasoning · Pro Over / Under ? 52% over MLB games, especially between teams with comparable historical offensive capabilities, tend to average around 7-9 runs. Without specific pit... Unlock reasoning · Pro Spread ? 53% Boston Red Sox Given the slight historical edge favoring the Red Sox in head-to-head matchups, they are also slightly favored to cover a small spread. This... Unlock reasoning · Pro First 5 innings ? No pick on this market. First five innings over 4.5 ? 51% over The first five innings often see a combination of starting pitcher performance and early offensive pushes. A total of 4.5 runs is a common b... Unlock reasoning · Pro
DeepSeek V3 Deepseek · 287-335 -201.7u	54% Seattle Mariners	52% Under 8.5	28% Seattle Mariners -1.5	55% Seattle Mariners	—
Match winner ? 54% Seattle Mariners The Mariners have a strong home record at T-Mobile Park, while the Red Sox have been inconsistent on the road. Pitching matchups slightly fa... Unlock reasoning · Pro Over / Under ? 52% Under 8.5 Both teams have been average offensively, and Seattle's pitchers have been solid at home. The under is slightly favored due to park factors... Unlock reasoning · Pro Spread ? 28% Seattle Mariners -1.5 The game is expected to be close, making a run-line cover difficult for Seattle. The Red Sox have kept games competitive, so the underdog co... Unlock reasoning · Pro First 5 innings ? 55% Seattle Mariners Seattle's starting pitching has been strong early in games, while Boston's starters have struggled in first five innings. Home advantage als... Unlock reasoning · Pro First five innings over 4.5 ? No pick on this market.
Consensus	Seattle Mariners 5/6	Under 8.5 2/6	Seattle Mariners 2/6	Seattle Mariners 4/5	over 1/1

Match winner

Consensus
Seattle Mariners 5/6

Claude Opus 4.7 Pro

Claude Opus 4.6 Pro

Claude Opus 4.8 Pro

Claude Sonnet 4.6 Pro

Claude Haiku 4.5 58% Seattle Mariners

As of my training data (through September 2025), the Mariners have been a competitive AL West team with strong pitching depth, while Boston...

Unlock reasoning · Pro

GPT-5 Pro

GPT-5 Mini —

GPT-4o Mini 55% Seattle Mariners

The Seattle Mariners have a strong home record, and the Boston Red Sox have struggled on the road this season. Additionally, the Mariners ha...

Unlock reasoning · Pro

🔍 researched 2 sources cited

o4-mini Pro

Grok 4.3 Pro

Grok 4 Fast 54% Seattle Mariners

Seattle has historically fielded stronger pitching staffs than Boston in recent seasons. Training data through 2025-09 shows Mariners favore...

Unlock reasoning · Pro

Gemini 3.1 Pro Pro

Gemini 2.5 Pro Pro

Gemini 2.5 Flash 55% Seattle Mariners

The Seattle Mariners typically leverage their home-field advantage and often feature strong starting pitching, which gives them a slight edg...

Unlock reasoning · Pro

Gemini 2.5 Flash-Lite 55% Boston Red Sox

Based on training data, the Boston Red Sox generally have a stronger historical performance against the Seattle Mariners. Without current fo...

Unlock reasoning · Pro

DeepSeek V3 54% Seattle Mariners

The Mariners have a strong home record at T-Mobile Park, while the Red Sox have been inconsistent on the road. Pitching matchups slightly fa...

Unlock reasoning · Pro

Over / Under

Consensus
Under 8.5 2/6

Claude Opus 4.7 Pro

Claude Opus 4.6 Pro

Claude Opus 4.8 Pro

Claude Sonnet 4.6 Pro

Claude Haiku 4.5 55% Over 8.5

Both teams have capable offenses; Mariners tend to score in day/evening splits, and Red Sox have mid-range run production. Without current p...

Unlock reasoning · Pro

GPT-5 Pro

GPT-5 Mini —

GPT-4o Mini 60% under

Both teams have strong pitching rotations, and the weather forecast suggests cooler temperatures, which typically lead to lower-scoring game...

Unlock reasoning · Pro

🔍 researched 2 sources cited

o4-mini Pro

Grok 4.3 Pro

Grok 4 Fast 51% over

June games at T-Mobile Park trend slightly above average run totals historically. Training data through 2025-09 indicates over hits in rough...

Unlock reasoning · Pro

Gemini 3.1 Pro Pro

Gemini 2.5 Pro Pro

Gemini 2.5 Flash 52% Under 8.5

Given the Mariners' general reputation for solid pitching and their home park tending to suppress offense, a lower-scoring game is slightly...

Unlock reasoning · Pro

Gemini 2.5 Flash-Lite 52% over

MLB games, especially between teams with comparable historical offensive capabilities, tend to average around 7-9 runs. Without specific pit...

Unlock reasoning · Pro

DeepSeek V3 52% Under 8.5

Both teams have been average offensively, and Seattle's pitchers have been solid at home. The under is slightly favored due to park factors...

Unlock reasoning · Pro

Spread

Consensus
Seattle Mariners 2/6

Claude Opus 4.7 Pro

Claude Opus 4.6 Pro

Claude Opus 4.8 Pro

Claude Sonnet 4.6 Pro

Claude Haiku 4.5 52% Seattle Mariners -1.5

Home-field advantage at T-Mobile Park and Mariners' historical reliability in close contests slightly favor a small margin win. However, wit...

Unlock reasoning · Pro

GPT-5 Pro

GPT-5 Mini —

GPT-4o Mini 50% Seattle Mariners

While the Mariners have a strong home record, the Red Sox have shown resilience in recent games. The spread is tight, and both teams have th...

Unlock reasoning · Pro

🔍 researched 2 sources cited

o4-mini Pro

Grok 4.3 Pro

Grok 4 Fast 52% Seattle Mariners

Seattle's bullpen depth often keeps games within a run or two at home. Training data through 2025-09 shows Mariners covering the run line at...

Unlock reasoning · Pro

Gemini 3.1 Pro Pro

Gemini 2.5 Pro Pro

Gemini 2.5 Flash 55% Boston Red Sox +1.5

Even if the Mariners win, baseball games are frequently decided by one run, making a -1.5 spread challenging to cover against a competitive...

Unlock reasoning · Pro

Gemini 2.5 Flash-Lite 53% Boston Red Sox

Given the slight historical edge favoring the Red Sox in head-to-head matchups, they are also slightly favored to cover a small spread. This...

Unlock reasoning · Pro

DeepSeek V3 28% Seattle Mariners -1.5

The game is expected to be close, making a run-line cover difficult for Seattle. The Red Sox have kept games competitive, so the underdog co...

Unlock reasoning · Pro

First 5 innings

Consensus
Seattle Mariners 4/5

Claude Opus 4.7 Pro

Claude Opus 4.6 Pro

Claude Opus 4.8 Pro

Claude Sonnet 4.6 Pro

Claude Haiku 4.5 54% Under 4.5

Early-game baseball typically sees lower run production as batters adjust to opposing starters. Without knowledge of the specific starting p...

Unlock reasoning · Pro

GPT-5 Pro

GPT-5 Mini —

GPT-4o Mini 55% Seattle Mariners

The Mariners' starting pitcher has been dominant in the first five innings this season, and the Red Sox have struggled against right-handed...

Unlock reasoning · Pro

🔍 researched 2 sources cited

o4-mini Pro

Grok 4.3 Pro

Grok 4 Fast 53% Seattle Mariners

Mariners starters have posted better early-inning results versus AL East clubs in past data. Training data through 2025-09 supports slight h...

Unlock reasoning · Pro

Gemini 3.1 Pro Pro

Gemini 2.5 Pro Pro

Gemini 2.5 Flash 53% Seattle Mariners

The Mariners' strength, particularly in their starting rotation, often allows them to establish an early lead or maintain parity through the...

Unlock reasoning · Pro

Gemini 2.5 Flash-Lite —

DeepSeek V3 55% Seattle Mariners

Seattle's starting pitching has been strong early in games, while Boston's starters have struggled in first five innings. Home advantage als...

Unlock reasoning · Pro

First five innings over 4.5

Consensus
over 1/1

Claude Opus 4.7 Pro

Claude Opus 4.6 Pro

Claude Opus 4.8 Pro

Claude Sonnet 4.6 Pro

Claude Haiku 4.5 —

GPT-5 Pro

GPT-5 Mini —

GPT-4o Mini —

o4-mini Pro

Grok 4.3 Pro

Grok 4 Fast —

Gemini 3.1 Pro Pro

Gemini 2.5 Pro Pro

Gemini 2.5 Flash —

Gemini 2.5 Flash-Lite 51% over

The first five innings often see a combination of starting pitcher performance and early offensive pushes. A total of 4.5 runs is a common b...

Unlock reasoning · Pro

DeepSeek V3 —

Pro on-demand

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Research trail

What each AI looked up before picking

Unlock sources · Pro

Claude Haiku 4.5
0 tool calls · 0 sources

No live web access — picked from training-data knowledge.
GPT-4o Mini
4 tool calls · 2 sources

2 citations captured — unlock with Pro
Grok 4 Fast
0 tool calls · 0 sources

No live web access — picked from training-data knowledge.
Gemini 2.5 Flash
0 tool calls · 0 sources

No live web access — picked from training-data knowledge.
Gemini 2.5 Flash-Lite
0 tool calls · 0 sources

No live web access — picked from training-data knowledge.
DeepSeek V3
0 tool calls · 0 sources

No live web access — picked from training-data knowledge.

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