Racing steamers and drifters

Cost: 3 credits. Runners whose price has moved materially since the market opened, across upcoming races.

move_pct is negative for a firming runner (the price shortened — money has arrived) and positive for a drifter.

open_price is the FIRST PRICE CAPTURED inside the 60-minute pre-race window, not a market open. Capture begins when the race enters that window, so how close that first price is to a true 60-minute open depends on the book — and it is not a clean two-way split. Measured over 13 days of snapshots, the share of series whose first capture sits at the 60-minute mark falls into three groups. sportsbet, betright and betr_au are there on 96-98% of series. tab, ladbrokes_au and neds are there on about 55%, but that figure swings between 16% and 77% from one day to the next, so for these three it is not a property you can rely on per book. playup (6%), unibet and pointsbetau (3%), tabtouch (1%) and palmerbet (0%) rarely or never are: palmerbet has not once been captured earlier than 33 minutes out across 23,641 series.

Do not infer any of this from the book. Read open_secs_to_jump on each bookmaker row, which says how far out that book's open actually was; /v1/racing/price-history additionally returns open_is_baseline per series.

A move is reported at the RUNNER level and only when at least min_books bookmakers have two or more captured prices, because a book seen only once has evidenced nothing: its open equals its current by construction. Those books are still listed, with points: 1 and counted_in_consensus: false, and still counted in books_quoting — but they do not enter the consensus or the gate. Use books_with_history as the confirmation count.

Broad-market support versus one book moving: read the breadth counters. books_firming, books_drifting and books_unchanged partition books_quoting, so they say how many books actually agreed with the headline move. A steam the market backs shows most of books_with_history moving the same way; a single-book move shows one, with the rest unchanged, and can still clear min_move_pct because the consensus averages over the few books that carry history. Measured live on 2026-09-01, Geelong R4 greyhound "Got Immunity" reported +102.8% drifting on 13 books quoting, of which 5 had history: 3 drifting, 1 firming, 9 unchanged - the headline number came from a minority. Gate on the counters, and on bookmakers[].move_pct where you need the per-book evidence, rather than on move_pct alone. Raising min_books raises how many books must carry history, not how many must agree.