Draw bias maps
Does the stall number matter? Here is the answer for every GB and Irish flat course, computed from 2023-06-01 to 2026-06-09 results (GB+IRE flat, fields of 6+ runners) — free, with the sample sizes shown so you can judge the evidence yourself.
The honest caveat most draw guides skip: a real bias is not automatically a profitable one. The A/E column compares each draw group's actual wins with what the Betfair market expected — where a famous bias shows IV above 1 but A/E below 1, the market already over-prices it.
Strongest draw effects (min 200 runs)
Ranked by distance from neutral (IV 1.00) in either direction.
| Course | Trip | Draw | Win % | IV | A/E | Runs |
|---|---|---|---|---|---|---|
| Galway | 7-8f | Middle | 2.3% | 0.33 | 1.23 | 220 |
| Galway | 7-8f | Low (inside) | 10.6% | 1.54 | 0.90 | 254 |
| Pontefract | 9-12f | Low (inside) | 16.7% | 1.50 | 1.17 | 209 |
| Chester | 5-6f | Low (inside) | 12.9% | 1.38 | 0.91 | 340 |
| Gowran Park | 7-8f | Low (inside) | 10% | 1.38 | 1.04 | 721 |
| York | 9-12f | Low (inside) | 11.1% | 1.38 | 1.07 | 370 |
| Yarmouth | 5-6f | Low (inside) | 14.9% | 1.37 | 1.22 | 490 |
| York | 5-6f | Low (inside) | 9.2% | 1.37 | 1.18 | 720 |
| Killarney | 7-8f | High (outside) | 5.4% | 0.63 | 0.72 | 278 |
| Limerick | 7-8f | Middle | 4.8% | 0.63 | 0.75 | 227 |
| Catterick | 5-6f | Low (inside) | 14.4% | 1.36 | 1.28 | 508 |
| Chester | 13f+ | Low (inside) | 13.6% | 1.36 | 1.08 | 279 |
Worked example: Chester
The most famous draw bias in racing, as it actually looks in the data. Low stalls dominate the tight turning sprints — but check the A/E before assuming the profit follows.
5-6f · 88 races · field avg win 9.4%
Strong: low (inside) favoured (IV 1.38)
| Draw | Win % | Top-3 % | IV | A/E | PRB | Runs |
|---|---|---|---|---|---|---|
| Low (inside) | 12.9% 44 wins | 22.6% | 1.38 vs course avg | 0.91 vs market | 68.4% | 340 |
| Middle | 8.3% 24 wins | 17% | 0.89 vs course avg | 0.66 vs market | 63.1% | 289 |
| High (outside) | 6.4% 20 wins | 10.3% | 0.69 vs course avg | 1.46 vs market | 57.3% | 312 |
Great Britain
Ascot350 races
5-6f
1.070.721.19
L · M · H7-8f
0.870.981.16
L · M · H9-12f
0.751.181.11
L · M · H13f+
1.181.050.77
L · M · H5-6f: moderate: high (outside) favoured (iv 1.19) · 7-8f: moderate: high (outside) favoured (iv 1.16) · 9-12f: moderate: middle favoured (iv 1.18)
Ayr348 races
5-6f
1.240.980.75
L · M · H7-8f
1.060.921.01
L · M · H9-12f
0.761.061.20
L · M · H13f+
0.861.141.03
L · M · H5-6f: moderate: low (inside) favoured (iv 1.24) · 9-12f: moderate: high (outside) favoured (iv 1.20)
Bath421 races
5-6f
1.121.060.81
L · M · H7-8f
1.180.970.82
L · M · H9-12f
1.061.080.87
L · M · H13f+
0.881.360.83
L · M · H5-6f: moderate: low (inside) favoured (iv 1.12) · 7-8f: moderate: low (inside) favoured (iv 1.18) · 13f+: strong: middle favoured (iv 1.36)
Beverley371 races
5-6f
1.191.060.74
L · M · H7-8f
1.080.801.09
L · M · H9-12f
1.100.980.90
L · M · H5-6f: moderate: low (inside) favoured (iv 1.19) · 7-8f: moderate: high (outside) favoured (iv 1.09)
Brighton349 races
5-6f
1.060.940.99
L · M · H7-8f
0.970.931.09
L · M · H9-12f
0.960.891.15
L · M · H9-12f: moderate: high (outside) favoured (iv 1.15)
Carlisle247 races
5-6f
0.991.100.91
L · M · H7-8f
1.000.831.16
L · M · H9-12f
1.310.890.75
L · M · H7-8f: moderate: high (outside) favoured (iv 1.16) · 9-12f: strong: low (inside) favoured (iv 1.31)
Catterick321 races
5-6f
1.360.790.80
L · M · H7-8f
1.021.130.86
L · M · H9-12f
0.850.741.40
L · M · H13f+
1.271.120.60
L · M · H5-6f: strong: low (inside) favoured (iv 1.36) · 7-8f: moderate: middle favoured (iv 1.13) · 9-12f: strong: high (outside) favoured (iv 1.40)
Chelmsford (AW) (AW)865 races
5-6f
1.241.000.73
L · M · H7-8f
1.111.110.78
L · M · H9-12f
1.280.930.75
L · M · H13f+
1.080.910.98
L · M · H5-6f: strong: low (inside) favoured (iv 1.24) · 7-8f: moderate: low (inside) favoured (iv 1.11) · 9-12f: strong: low (inside) favoured (iv 1.28)
Chepstow257 races
5-6f
1.000.901.08
L · M · H7-8f
1.060.950.98
L · M · H9-12f
1.211.020.76
L · M · H9-12f: moderate: low (inside) favoured (iv 1.21)
Chester297 races
5-6f
1.380.890.69
L · M · H7-8f
1.110.751.11
L · M · H9-12f
1.230.970.76
L · M · H13f+
1.360.800.79
L · M · H5-6f: strong: low (inside) favoured (iv 1.38) · 7-8f: moderate: low (inside) favoured (iv 1.11) · 9-12f: moderate: low (inside) favoured (iv 1.23) · 13f+: strong: low (inside) favoured (iv 1.36)
Doncaster505 races
5-6f
0.960.931.11
L · M · H7-8f
1.100.920.97
L · M · H9-12f
1.201.050.73
L · M · H13f+
1.450.920.57
L · M · H9-12f: moderate: low (inside) favoured (iv 1.20)
Epsom208 races
5-6f
1.020.981.00
L · M · H7-8f
0.950.901.14
L · M · H9-12f
0.990.871.14
L · M · H9-12f: moderate: high (outside) favoured (iv 1.14)
Ffos Las139 races
5-6f
0.811.270.97
L · M · H7-8f
0.911.081.03
L · M · H9-12f
0.951.011.04
L · M · H5-6f: moderate: middle favoured (iv 1.27)
Goodwood367 races
5-6f
1.330.960.66
L · M · H7-8f
1.151.070.77
L · M · H9-12f
0.821.191.02
L · M · H13f+
1.041.290.70
L · M · H5-6f: strong: low (inside) favoured (iv 1.33) · 7-8f: moderate: low (inside) favoured (iv 1.15) · 9-12f: moderate: middle favoured (iv 1.19) · 13f+: strong: middle favoured (iv 1.29)
Hamilton308 races
5-6f
1.191.000.79
L · M · H9-12f
0.951.021.04
L · M · H5-6f: moderate: low (inside) favoured (iv 1.19)
Haydock411 races
5-6f
1.220.711.02
L · M · H7-8f
1.240.790.93
L · M · H9-12f
1.200.850.91
L · M · H13f+
1.160.940.88
L · M · H5-6f: strong: low (inside) favoured (iv 1.22) · 7-8f: moderate: low (inside) favoured (iv 1.24) · 9-12f: moderate: low (inside) favoured (iv 1.20)
Kempton (AW) (AW)1227 races
5-6f
1.330.890.74
L · M · H7-8f
1.051.170.80
L · M · H9-12f
0.991.210.83
L · M · H13f+
1.350.780.82
L · M · H5-6f: strong: low (inside) favoured (iv 1.33) · 7-8f: moderate: middle favoured (iv 1.17) · 9-12f: moderate: middle favoured (iv 1.21) · 13f+: strong: low (inside) favoured (iv 1.35)
Leicester349 races
5-6f
1.130.930.92
L · M · H7-8f
1.031.170.81
L · M · H9-12f
0.911.071.03
L · M · H7-8f: moderate: middle favoured (iv 1.17)
Lingfield232 races
5-6f
0.831.211.00
L · M · H7-8f
1.001.140.88
L · M · H9-12f
1.140.880.96
L · M · H5-6f: moderate: middle favoured (iv 1.21) · 7-8f: moderate: middle favoured (iv 1.14) · 9-12f: moderate: low (inside) favoured (iv 1.14)
Lingfield (AW) (AW)1010 races
5-6f
0.961.031.02
L · M · H7-8f
0.771.111.15
L · M · H9-12f
0.821.250.97
L · M · H13f+
0.811.231.00
L · M · H7-8f: moderate: high (outside) favoured (iv 1.15) · 9-12f: moderate: middle favoured (iv 1.25) · 13f+: moderate: middle favoured (iv 1.23)
Musselburgh299 races
5-6f
0.890.851.25
L · M · H7-8f
0.850.971.20
L · M · H9-12f
0.981.190.85
L · M · H13f+
1.170.641.13
L · M · H5-6f: moderate: high (outside) favoured (iv 1.25) · 7-8f: moderate: high (outside) favoured (iv 1.20) · 13f+: strong: low (inside) favoured (iv 1.17)
Newbury381 races
5-6f
1.000.931.07
L · M · H7-8f
0.991.160.86
L · M · H9-12f
1.150.910.92
L · M · H13f+
0.881.081.06
L · M · H7-8f: moderate: middle favoured (iv 1.16)
Newcastle (AW) (AW)1518 races
5-6f
1.020.881.09
L · M · H7-8f
0.941.061.01
L · M · H9-12f
0.941.071.01
L · M · H13f+
1.060.901.02
L · M · HNo strong bias called
Newmarket373 races
5-6f
1.040.801.13
L · M · H7-8f
1.080.871.04
L · M · H9-12f
0.771.231.04
L · M · H5-6f: moderate: high (outside) favoured (iv 1.13) · 9-12f: moderate: middle favoured (iv 1.23)
Newmarket (July)318 races
5-6f
0.950.801.24
L · M · H7-8f
0.911.061.05
L · M · H9-12f
0.911.300.82
L · M · H5-6f: moderate: high (outside) favoured (iv 1.24) · 9-12f: moderate: middle favoured (iv 1.30)
Nottingham386 races
5-6f
0.901.041.08
L · M · H9-12f
0.910.991.11
L · M · H13f+
0.661.141.26
L · M · H13f+: strong: high (outside) favoured (iv 1.26)
Pontefract280 races
5-6f
0.981.190.85
L · M · H7-8f
1.290.850.83
L · M · H9-12f
1.500.990.47
L · M · H5-6f: moderate: middle favoured (iv 1.19) · 7-8f: moderate: low (inside) favoured (iv 1.29) · 9-12f: strong: low (inside) favoured (iv 1.50)
Redcar308 races
5-6f
1.020.980.99
L · M · H7-8f
1.060.980.95
L · M · H9-12f
1.120.960.91
L · M · HNo strong bias called
Ripon301 races
5-6f
0.941.150.93
L · M · H7-8f
0.901.031.08
L · M · H9-12f
1.080.930.97
L · M · HNo strong bias called
Salisbury245 races
5-6f
0.970.881.14
L · M · H7-8f
0.891.160.98
L · M · H9-12f
0.740.871.39
L · M · H5-6f: moderate: high (outside) favoured (iv 1.14) · 7-8f: moderate: middle favoured (iv 1.16) · 9-12f: strong: high (outside) favoured (iv 1.39)
Sandown240 races
5-6f
1.180.641.12
L · M · H7-8f
1.100.851.02
L · M · H9-12f
0.910.731.35
L · M · H5-6f: strong: low (inside) favoured (iv 1.18) · 7-8f: moderate: low (inside) favoured (iv 1.10) · 9-12f: strong: high (outside) favoured (iv 1.35)
Southwell (AW) (AW)1348 races
5-6f
1.090.960.94
L · M · H7-8f
0.961.041.01
L · M · H9-12f
1.051.080.88
L · M · H13f+
0.841.161.03
L · M · H13f+: moderate: middle favoured (iv 1.16)
Thirsk327 races
5-6f
0.731.081.22
L · M · H7-8f
0.821.041.16
L · M · H9-12f
0.711.490.87
L · M · H5-6f: moderate: high (outside) favoured (iv 1.22) · 7-8f: moderate: high (outside) favoured (iv 1.16)
Windsor501 races
5-6f
0.881.051.09
L · M · H7-8f
1.021.050.93
L · M · H9-12f
0.961.210.85
L · M · H9-12f: moderate: middle favoured (iv 1.21)
Wolverhampton (AW) (AW)1923 races
5-6f
1.240.910.83
L · M · H7-8f
1.051.090.86
L · M · H9-12f
0.961.120.94
L · M · H13f+
0.891.111.02
L · M · H5-6f: moderate: low (inside) favoured (iv 1.24)
Yarmouth435 races
5-6f
1.370.880.70
L · M · H7-8f
1.081.020.89
L · M · H9-12f
1.181.090.72
L · M · H5-6f: strong: low (inside) favoured (iv 1.37) · 9-12f: moderate: low (inside) favoured (iv 1.18)
York346 races
5-6f
1.370.900.69
L · M · H7-8f
1.221.060.71
L · M · H9-12f
1.380.710.87
L · M · H13f+
1.160.571.21
L · M · H5-6f: strong: low (inside) favoured (iv 1.37) · 7-8f: strong: low (inside) favoured (iv 1.22) · 9-12f: strong: low (inside) favoured (iv 1.38)
Ireland
Cork200 races
5-6f
1.130.950.90
L · M · H7-8f
0.961.070.97
L · M · H9-12f
0.791.211.04
L · M · H9-12f: moderate: middle favoured (iv 1.21)
Curragh544 races
5-6f
1.030.841.12
L · M · H7-8f
0.960.991.04
L · M · H9-12f
1.101.130.78
L · M · H13f+
1.141.020.83
L · M · H5-6f: moderate: high (outside) favoured (iv 1.12) · 9-12f: moderate: middle favoured (iv 1.13)
Down Royal127 races
5-6f
0.581.331.13
L · M · H7-8f
0.821.360.87
L · M · H9-12f
0.520.981.52
L · M · H13f+
0.921.310.81
L · M · HNo strong bias called
Dundalk (AW) (AW)954 races
5-6f
0.941.061.02
L · M · H7-8f
1.041.110.86
L · M · H9-12f
0.891.091.04
L · M · H13f+
1.110.880.98
L · M · H7-8f: moderate: middle favoured (iv 1.11)
Fairyhouse117 races
5-6f
1.080.811.10
L · M · H7-8f
1.011.160.84
L · M · H9-12f
1.300.750.91
L · M · H5-6f: moderate: high (outside) favoured (iv 1.10)
Galway119 races
7-8f
1.540.331.05
L · M · H9-12f
1.340.820.81
L · M · H7-8f: strong: low (inside) favoured (iv 1.54) · 9-12f: strong: low (inside) favoured (iv 1.34)
Gowran Park240 races
7-8f
1.380.820.75
L · M · H9-12f
1.110.731.13
L · M · H7-8f: strong: low (inside) favoured (iv 1.38) · 9-12f: moderate: high (outside) favoured (iv 1.13)
Killarney99 races
7-8f
1.241.120.63
L · M · H9-12f
1.221.210.56
L · M · H7-8f: strong: low (inside) favoured (iv 1.24)
Leopardstown326 races
7-8f
1.160.880.94
L · M · H9-12f
1.121.240.64
L · M · H13f+
1.180.890.91
L · M · H7-8f: moderate: low (inside) favoured (iv 1.16) · 9-12f: strong: middle favoured (iv 1.24)
Naas258 races
5-6f
1.100.920.97
L · M · H7-8f
1.031.140.84
L · M · H9-12f
0.631.161.28
L · M · H7-8f: moderate: middle favoured (iv 1.14)
Navan191 races
5-6f
1.110.771.10
L · M · H9-12f
1.031.050.92
L · M · H13f+
0.880.941.19
L · M · H5-6f: moderate: low (inside) favoured (iv 1.11)
Roscommon130 races
7-8f
1.261.090.64
L · M · H9-12f
0.910.961.13
L · M · H7-8f: strong: low (inside) favoured (iv 1.26)
Methodology
Window 2023-06-01 → 2026-06-09, GB+IRE flat races with 6+ actual runners. Stalls are ranked among the horses that actually ran (so withdrawals don't distort the thirds), then split low / middle / high.
IV = group win rate ÷ win rate of all runners at the same course, surface and distance band. A/E= actual wins ÷ expected wins, where each runner's expectation is its de-overrounded Betfair SP implied probability (industry SP as fallback; races without full price coverage are excluded from A/E only). PRB = mean percentage of rivals beaten, finishers only. Run-style splits come from in-running comments and only show where a style has 20+ runs.
Nothing here is smoothed, weighted or suppressed. Small samples are shown with their run counts — treat anything under a few hundred runs as a hint, not a rule. Past draw patterns can change with rail movements, going and stalls positioning.