Is there a draw bias at Roscommon?
Yes, in places. Across 130 races from 2023-06-01 to 2026-06-09: over 7-8f — strong: low (inside) favoured (iv 1.26). Check the A/E column before betting it: a bias the market already prices in is not an edge.
Roscommon draw bias
Yes, in places. Across 130 races from 2023-06-01 to 2026-06-09: over 7-8f — strong: low (inside) favoured (iv 1.26). Check the A/E column before betting it: a bias the market already prices in is not an edge.
2023-06-01 – 2026-06-09 results · 130 races · updated 9 June 2026
7-8f · 66 races
Strong: low (inside) favoured (IV 1.26)7-8f · 66 races · field avg win 7.3%
Strong: low (inside) favoured (IV 1.26)
| Draw | Win % | Top-3 % | IV | A/E | PRB | Runs |
|---|---|---|---|---|---|---|
| Low (inside) | 9.3% 29 wins | 15% | 1.26 vs course avg | 0.69 vs market | 68.2% | 313 |
| Middle | 8% 23 wins | 12.5% | 1.09 vs course avg | 1.06 vs market | 64.4% | 289 |
| High (outside) | 4.7% 14 wins | 10.4% | 0.64 vs course avg | 1.39 vs market | 53.8% | 299 |
9-12f · 64 races
No meaningful draw bias9-12f · 64 races · field avg win 8%
No meaningful draw bias
| Draw | Win % | Top-3 % | IV | A/E | PRB | Runs |
|---|---|---|---|---|---|---|
| Low (inside) | 7.3% 21 wins | 15.3% | 0.91 vs course avg | 1.11 vs market | 67.4% | 287 |
| Middle | 7.7% 19 wins | 12.6% | 0.96 vs course avg | 1.28 vs market | 58.4% | 246 |
| High (outside) | 9.1% 24 wins | 14.7% | 1.13 vs course avg | 0.48 vs market | 59.5% | 265 |
Common questions
Does the market already price in the Roscommon draw bias?
Largely, yes. Every favoured third at Roscommon shows A/E below 1 — the market over-bets the famous stalls, so blindly backing the bias has lost money against Betfair prices.
What do IV, A/E and PRB mean?
IV (Impact Value) is the group's win rate versus all runners in the same races — 1.00 is neutral. A/E is actual wins versus what de-overrounded Betfair prices expected — below 1 means the market over-bets that group. PRB is the mean percentage of rivals beaten, a finer-grained placing measure.
Keep going
Method: stall numbers grouped into field thirds (low/middle/high) per race, so field size never skews the groups; IV against same-course same-band baseline; A/E against de-overrounded Betfair SP. Small samples are flagged rather than hidden. Racing Alpha does not accept bets. 18+ · BeGambleAware.org.