H45: young horses in novice chases

Mechanism and rationale

Four- and five-year-olds in non-handicap novice chases: precocious types sent chasing young for a reason.

The rule

race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5

Reads: race_type, is_novice, is_handicap, age

Pre-registration

Spec hash (sha256 of the canonical pre-spec)

not designed yet

Frozen

not frozen

The definition can still change.

Broad

race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5

Kind

all

Origin

research/experiments/overnight/results_v2.jsonl

Refinements

[
  {
    "name": "has won over hurdles",
    "rule": "(race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5) AND (hurdle_wins >= 1)"
  },
  {
    "name": "chase debut",
    "rule": "(race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5) AND (chase_runs = 0)"
  },
  {
    "name": "Britain",
    "rule": "(race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5) AND (region = 'GB')"
  }
]

Tier

B

Result (from the archive)

info Britain · 15 Oct, 23:10

Bets

204

A/E

0.96

winners vs the prices

SP return

+8.4%

level stakes

Betfair SP return

–

18 bets with a BSP

Strike rate 23.0%.

Falsification

No attacks yet. Only promising ideas are attacked.

Sealed holdout (vault)

Not queried. Only a frozen idea can spend its one query against the 2020-25 holdout.

Forward record

No forward record. Shadow tracking starts after the vault and counts only races run after the freeze.

Lineage

Agent runs

• investigator v1ok · 40s · 16 Oct, 11:03

  Output (schema-checked)

  {
    "reflection": "This thread is one rule: four- and five-year-olds in non-handicap novice chases. Earlier research made it GREEN at A/E 1.095 on 435 bets, and it is now a LIVE system. The edge is uneven across periods. The first period, with 254 bets, was flat at 1.00. All of the lift comes from the later 181 bets (1.27 on 128, then 1.15 on 53). The lab's own measurement of the same rule on the window it scores (discovery) came out at 0.963 on 204 bets, below the market. So the chain has taught us less than the GREEN label suggests. The mechanism is that yards only send a horse chasing this young once it has shown them it can jump, and the market reads such a horse as immature. That is plausible, but the evidence is one period-dependent result that the lab's re-measurement has not reproduced. The earlier figure may have used a yardstick not corrected for field size, and novice chases have small fields; four early greens were lost to that correction. Nothing has yet tested the mechanism itself. If the yard's private view of the horse's jumping is what the market misses, the effect should be strongest where the public has least evidence: before the horse has run over fences.",
    "answers": [],
    "questions": [
      {
        "question": "Why does the lab's discovery measurement (A/E 0.963 on 204) disagree with the imported GREEN (1.095 on 435)? Is it the field-size-corrected yardstick, the window, or the edge fading?",
        "rationale": "If the field-size-corrected yardstick explains the gap, the live system rests on a mismeasurement and should be reviewed. Compare the same rule under both yardsticks and against the other runners in the same races, splitting by field_size and sp_rank. Read field_size, sp_decimal, sp_rank and region.",
        "observation_ids": [
          "O-35f7497e"
        ],
        "priority": 0.8
      },
      {
        "question": "Is the young-novice-chaser lift concentrated on chase debuts (chase_runs = 0), where only the yard knows how well the horse jumps?",
        "rationale": "This is a direct test of the mechanism. The market can see a young horse's later chase runs, but not its schooling before its first. Read chase_runs, chase_wins, age and jumping_errors_last3. It should be set against H124, where fit hurdlers on their chase debut were over-bet (0.91).",
        "observation_ids": [
          "O-35f7497e",
          "O-b063770a"
        ],
        "priority": 0.6
      },
      {
        "question": "Is the effect stronger at age 4 than at age 5, as the mechanism predicts, since sending a four-year-old over fences is the rarer and more deliberate choice?",
        "rationale": "The mechanism says rarity signals intent, so the effect should be strongest at age = 4. Read age, trainer and region; four-year-old chasers are often French-bred and may cluster in a few yards, which would need checking.",
        "observation_ids": [
          "O-35f7497e"
        ],
        "priority": 0.4
      }
    ],
    "hypotheses": [
      {
        "title": "Young novice chasers on their chase debut beat their price",
        "family": "age",
        "operator": "test-mechanism",
        "question_id": null,
        "new_question": 1,
        "parent_id": "H45-young-horses-in-novice-chases",
        "reasoning": {
          "observation_ids": [
            "O-35f7497e",
            "O-b063770a"
          ],
          "question": "Is the young-novice-chaser edge concentrated on the horse's first chase run, where only the yard has seen it jump?",
          "mechanism": "A yard sends a four- or five-year-old over fences only after schooling shows it jumps well. On its chase debut that private judgement is the only information available, and the young age is the visible sign of it.",
          "market_miss": "The public form is all hurdles. The market prices the horse as an immature hurdler taking on older, stronger chasers, and has no evidence of its jumping. After a run or two over fences its jumping is on view and gets priced.",
          "prediction": {
            "direction": "positive",
            "size": "A/E 1.08 to 1.15 on 100+ bets",
            "falsified_if": "A/E at or below 1.00, or no higher than the same rule with chase_runs >= 1"
          },
          "rule_sketch": "race_type = 'Chase' AND is_novice = 1 AND is_handicap = 0 AND age <= 5 AND chase_runs = 0"
        },
        "confounders": [
          "small field sizes in novice chases",
          "general over-betting of chase debutants (H124 at 0.91)",
          "French-bred imports concentrated in a few yards",
          "short-priced favourites dominate small novice chases"
        ],
        "expected_survival": 0.3
      },
      {
        "title": "Young horses in handicap chases also beat their price",
        "family": "age",
        "operator": "generalise",
        "question_id": null,
        "new_question": 0,
        "parent_id": "H45-young-horses-in-novice-chases",
        "reasoning": {
          "observation_ids": [
            "O-35f7497e"
          ],
          "question": "Does the young-chaser signal hold outside non-handicap novice chases, which would show it is about the horse rather than a property of small novice races?",
          "mechanism": "The cause is the same: a yard has chosen to run a horse of five or younger over fences, which signals confidence in its jumping and its physical maturity. That choice does not depend on the race being a non-handicap novice chase.",
          "market_miss": "In handicaps, older and more exposed horses set the reference point. The young horse's low mark is read as its limit, not as a horse still improving with experience over fences.",
          "prediction": {
            "direction": "positive",
            "size": "A/E 1.05 to 1.12 on 200+ bets",
            "falsified_if": "A/E at or below 1.00 across the periods, which would point to the novice-race result being a property of those races (field size or price)"
          },
          "rule_sketch": "race_type = 'Chase' AND is_handicap = 1 AND age <= 5"
        },
        "confounders": [
          "field size",
          "weight-for-age allowances in handicaps",
          "trainer concentration (French-bred stock)",
          "youth read as potential is generally over-paid (family finding)"
        ],
        "expected_survival": 0.25
      }
    ],
    "findings": [
      {
        "statement": "The young-novice-chaser edge is period-dependent: the first period was flat at 1.00 on 254 bets, and all of the lift comes from the later 181 bets (1.27, 1.15).",
        "kind": "data",
        "observation_ids": [
          "O-35f7497e"
        ]
      },
      {
        "statement": "The lab's re-measurement of the H45 rule gave A/E 0.963 on 204 bets against the imported 1.095, so the live system's edge is not yet reproduced under the lab's yardstick.",
        "kind": "fails",
        "observation_ids": [
          "O-35f7497e"
        ]
      }
    ]
  }

Timeline

1. hypothesis note H45-young-horses-in-novice-chases

   15 Oct, 23:10 · importer

2. H45-young-horses-in-novice-chases Discovery → PROMISING import: tier B: interesting, unproven; best [broad] GREEN A/E 1.095 on 435 bets (broad GREEN)

   15 Oct, 23:10 · importer

3. import result for H45-young-horses-in-novice-chases (Britain): info

   15 Oct, 23:10 · importer

4. import result for H45-young-horses-in-novice-chases (chase debut): info

   15 Oct, 23:10 · importer

5. import result for H45-young-horses-in-novice-chases (has won over hurdles): info

   15 Oct, 23:10 · importer

6. import result for H45-young-horses-in-novice-chases (broad): info

   15 Oct, 23:10 · importer

7. New idea H45-young-horses-in-novice-chases: H45: young horses in novice chases (import)

   15 Oct, 23:10 · importer

Every change is an event with an actor: an agent and its version, an engine, a human, or the importer. Current stage: Promising.