Labs · Trap bias

The draw is worth 10.9 points.

Across 522,492 australian races, the best trap beats the worst by 10.9 percentage points on average at the 162 track distances where the draw measurably matters.

522,492 races chi-squared, p < 0.001 show Great Britain run it yourself
162 of 176 track distances with a real biasthe rest are within chance
139 of 162 where trap 1 is bestthe other traps take the rest
17 of 162 where the outside is worstthe low end is consistent
10.9pp average gap, best to worst 12.5% is an even draw

What the data says

The outside can win

At Murray Bridge Straight 300m, trap 8 wins most — 17.1% across 2,476 races. That is the opposite of what the draw is supposed to do, and it happens at 14 distances.

The same track can flip

At Bulli, 340m favours trap 2, 400m favours trap 2, 472m favours trap 1.

Bias belongs to the track and the distance. Treating a course as having one bias loses most of the effect — and 9 tracks do this.

Losing is the predictable part

Which trap wins varies. Which trap loses barely does: the outside two are worst at 17 of the 162.

So the draw is a reliable handicap even where it is an unreliable advantage.

Every australian track and distance

Winners only. A combination appears once it has 400 races; the ones marked real are those where a chi-squared test says a draw this uneven would turn up by chance less than once in a thousand times.

Traps 1 2 3 4 5 6
above an even draw below best trap
TrackDistanceRaces T1T2T3T4T5T6 GapVerdict
Angle Park 388m 1,116 23.7 19.7 1.8 13.7 14.2 3 21.9 real
Cannington 381m 486 26.7 18.1 9.7 13.4 10.3 5.8 20.9 real
Angle Park 342m 4,223 23.2 16.9 3 15.5 13.1 4.3 20.2 real
Mount Gambier 305m 1,134 22 16.8 1.9 15.6 10.8 6.1 20.1 real
Mount Gambier 400m 4,298 24.3 16.7 5.8 13.3 10.5 5.4 18.9 real
Wangaratta 400m 988 24.8 8.6 13.5 6.7 12.4 5.9 18.9 real
Gawler 400m 5,977 21.6 17.6 3.8 14.9 11.6 5.1 17.8 real
Angle Park 515m 1,547 22.6 18 5.5 13.1 11.1 5.4 17.2 real
Broken Hill 375m 1,211 23.7 17.2 11.1 13 6.9 7.3 16.8 real
Mandurah 488m 1,245 23.5 15.4 12.1 10.4 8.6 6.9 16.6 real
Cannington 715m 403 19.6 15.1 3.7 18.1 6.5 13.4 15.9 real
Angle Park 530m 3,072 22 16.3 6.7 14.2 9.6 7.9 15.3 real
Horsham 336m 1,157 22.6 17.2 10.6 10.2 11.5 8.6 15.2 real
Gawler 531m 1,569 21.2 15.1 6.1 14.3 11 8.2 15.1 real
Murray Bridge 395m 2,350 18.5 16.9 3.7 15.2 10 7.9 14.8 real
Northam 509m 927 22.9 15.9 9.6 14.2 9.6 8.1 14.8 real
Traralgon 298m 2,100 22.9 14.1 11 11.9 8.1 8.1 14.8 real
Albion Park 395m 3,746 22.5 17.7 12.7 12.3 9.3 8.3 14.7 real
Bulli 340m 1,301 18 19.9 12.7 13 5.4 7.2 14.5 real
Dubbo 400m 1,395 22.9 15.1 9.8 14.2 10 8.5 14.4 real
Albion Park 600m 741 20.8 17 11.9 13.2 6.5 9.4 14.3 real
Ballarat 550m 1,753 22.1 15.5 13.5 11.1 9.6 7.9 14.2 real
Angle Park 595m 514 21 18.3 7 15.4 7.8 10.5 14 real
Richmond 535m 527 20.5 15.7 12.9 12.9 8.7 6.6 13.9 real
Sandown (SAP) 595m 1,373 21.9 17.4 10.3 12.2 8 9.4 13.9 real
Wangaratta 403m 3,012 21.2 16.6 7.3 12.4 7.3 10.3 13.9 real
The Meadows 518m 1,190 21.4 16.4 11.3 11.7 11.4 10.1 13.8 real
Mount Gambier 512m 1,939 20.4 16.6 6.7 13.7 9.9 7.9 13.7 real
Sale 511m 570 21.4 13.7 12.8 9.8 10.9 8.8 13.7 real
Wentworth Park 720m 467 21.4 14.1 7.7 11.3 10.9 9 13.7 real
Winnellie Park 537m 491 16.9 19.6 5.9 13.8 5.9 13.8 13.7 real
Taree 392m 535 21.1 15.3 13.3 13.1 8.6 7.7 13.4 real
Bendigo 545m 1,786 21.7 14.9 12.4 10.7 9.7 8.4 13.3 real
Richmond 401m 2,640 22.5 16.6 11.1 10 9.6 9.2 13.3 real
Horsham 570m 974 21.4 15.3 15.3 12.1 9.3 9.3 13.1 real
Murray Bridge Straight 300m 2,476 15.9 16.9 4.2 15.3 10.4 8 12.9 real
Wagga Wagga 525m 497 21.1 15.5 12.7 11.5 8.2 8.7 12.9 real
Casino 411m 2,270 20.7 14.4 10.6 10.4 7.9 10.1 12.8 real
Mandurah 490m 1,757 21.1 14.1 9.5 13 10.2 8.3 12.8 real
Richmond 520m 1,138 20.9 17.2 12.5 11.5 8.6 8.1 12.8 real
Sale 510m 650 20.6 16.3 11.1 10.2 7.8 9.4 12.8 real
Ipswich 288m 2,732 21.2 13.5 11.5 10.3 11.3 8.5 12.7 real
Ladbrokes Q2 Parklands 520m 814 19.8 16 11.3 13.3 7.1 9.6 12.7 real
Richmond 400m 1,770 21.2 13.3 12.4 11 10.6 8.5 12.7 real
Sandown (SAP) 515m 5,300 21.6 17.4 12.5 11.2 8.9 10 12.7 real
Bathurst 450m 574 20.6 16.7 11 11.8 8.7 9.9 12.6 real
Meadows (MEP) 600m 1,189 21.3 16.4 10.3 11.4 8.8 10.3 12.5 real
Casino 300m 2,339 19.6 12.4 11.9 13.7 7.4 11.2 12.2 real
Coonamble 305m 401 17.7 13.7 8.5 12 5.5 11.7 12.2 real
Ipswich 431m 5,882 20.7 17.8 12.9 11.6 8.5 8.7 12.2 real
Betdeluxe Rockhampton 510m 687 18.9 16.4 11.5 14.1 6.8 9.9 12.1 real
Mandurah 300m 2,371 21.1 14.7 12.5 11.2 11.1 9.2 12.1 real
Sandown Park 595m 2,246 20.6 16.1 12.5 11.9 10 10.2 12.1 real
Bendigo 430m 9,275 19.7 12.5 7.7 11.4 8.6 10.9 12 real
Dubbo 516m 584 20 14.4 9.2 16.3 8.4 8 12 real
Ipswich 520m 2,563 20.2 13.7 13.7 12.9 8.5 8.9 11.7 real
Launceston 278m 1,842 21.2 15.2 12.2 9.9 10.4 10.4 11.7 real
Launceston 515m 1,609 20.3 16.1 12.3 12.1 10.4 8.6 11.7 real
Sale 520m 2,595 20.4 14.5 12.5 10.4 9 8.8 11.6 real
Sale 650m 642 19.5 16.2 12 13.1 7.9 10 11.6 real
Lismore 259m 455 19.6 13.2 8.1 13.4 9.9 10.1 11.5 real
Murray Bridge Straight 350m 731 17 17 5.5 15.6 9.2 8.5 11.5 real
Wauchope 384m 413 18.4 12.1 10.2 14 7 12.1 11.4 real
The Gardens 272m 1,361 19.2 15.4 12.6 11 7.9 12.2 11.3 real
Traralgon 513m 6,682 20.1 14 10.4 10 8.8 10.2 11.3 real
Wagga Wagga 400m 1,121 19.5 14.9 10 11.5 12.1 8.2 11.3 real
Winnellie Park 383m 1,574 19.2 16.9 7.9 14.1 8.3 10.1 11.3 real
Wagga Wagga 320m 2,123 18.6 13.1 11.1 7.4 8.8 10.3 11.2 real
Bet Nation Townsville 498m 1,505 19.5 15.7 11.2 11.4 8.4 10.5 11.1 real
Betdeluxe Rockhampton 407m 4,167 19.8 15.1 13.2 11.8 9 8.7 11.1 real
Traralgon 395m 3,125 20.7 15.7 12.5 9.7 9.6 11 11.1 real
Meadows (MEP) 525m 5,716 19.2 16.5 10.4 14 8.2 9.3 11 real
Sale 424m 1,743 16.2 10.3 9.6 8.9 10 10.3 11 real
Albion Park 520m 4,751 18.9 17.4 12.4 12.5 8 9.7 10.9 real
Nowra 520m 1,009 19.1 18.4 9.8 13.1 10.7 8.2 10.9 real
Cannington 380m 3,800 20.1 15.2 11.9 12.6 10.8 9.3 10.8 real
Geelong 600m 904 19.7 15.6 11.2 13.1 12.2 10.2 10.7 real
Goulburn 350m 2,922 19.3 13.9 11.9 12.3 8.6 9.7 10.7 real
Horsham 410m 7,184 19.6 15.3 11.4 11.6 8.9 9.9 10.7 real
Traralgon 525m 1,114 19.2 14.8 15.4 11 11 10.6 10.7 real
Warrnambool 450m 11,562 20 13.9 10.5 10.1 9.4 10.1 10.6 real
Northam 297m 1,535 19.6 15.4 11.4 12.6 11.5 9.7 10.5 real
Shepparton 440m 2,766 17 11.5 10.2 9.1 8.7 10.7 10.5 real
Winnellie Park 312m 2,362 14.7 16.9 6.4 16.2 9.6 8.9 10.5 real
Ballarat 450m 16,879 19.6 14.5 9.8 12.1 9.2 10.4 10.4 real
Maitland 450m 991 17.8 17.5 10.6 11.9 8.3 7.4 10.4 real
Nowra 365m 2,800 19.5 17.1 10.9 10.9 9.1 9.7 10.4 real
The Meadows 525m 15,766 20 15.8 12.6 11.7 9.9 9.6 10.4 real
Traralgon 350m 1,370 18 15.8 10.1 12.4 7.6 10.2 10.4 real
Warragul 424m 6,127 19.5 11.6 9.3 9.1 10.1 9.9 10.4 real
Casino 484m 762 18.8 14.4 10.1 11.4 8.5 8.7 10.3 real
Murray Bridge 455m 1,225 16.9 14.9 6.6 16 9.6 8.5 10.3 real
The Gardens 515m 2,167 19.3 17.7 10.6 13.3 10.4 9 10.3 real
Geelong 347m 2,567 20.3 12.7 10.1 10.4 10.2 10.3 10.2 real
Albion Park 331m 3,787 20.2 14.2 12.3 11.5 10.4 10.6 10 real
Ballarat 545m 2,014 19.1 14.8 11.3 11 10.6 9.1 10 real
Horsham 480m 5,017 20 14.4 10.9 11.2 10 10.6 10 real
Taree 314m 654 18.7 15.4 11.8 10.7 11.2 8.7 10 real
The Gardens 400m 5,346 19.8 14.7 11.8 11.1 9.8 10 10 real
Wangaratta 474m 2,079 19 13.8 11.2 9 11.1 9 10 real
Sandown Park 515m 17,648 19.1 16.2 12.7 11.5 10 9.2 9.9 real
Devonport At Launceston 278m 735 18.6 14.3 13.5 12 8.8 11.4 9.8 real
Geelong 520m 866 18.1 15.8 15.7 14 9.4 9.6 9.8 real
Traralgon 315m 1,129 18.2 14 11.8 10 8.4 11.7 9.8 real
Cannington 600m 587 16 15.7 6.3 15.3 11.1 7.7 9.7 real
Bathurst 307m 1,012 18.3 12.9 13.5 11.7 11.3 8.7 9.6 real
Cranbourne 311m 8,293 18.3 14.6 8.7 12.6 8.9 10.6 9.6 real
Shepparton 385m 3,056 17.7 14 11.5 12.9 8.1 9.6 9.6 real
Wentworth Park 520m 6,511 18.8 14.7 11.4 11.5 9.3 10.6 9.5 real
Dapto 520m 1,322 17.2 17.2 10.1 13.5 7.8 8.9 9.4 real
Gunnedah 431m 959 18.7 16.9 11.6 11.7 9.3 9.6 9.4 real
Dubbo 318m 2,408 19.7 14.5 10.4 12.8 10.8 10.5 9.3 real
Goulburn 440m 1,718 18 15.1 8.7 13.3 8.9 8.9 9.3 real
Cannington 275m 2,890 18.9 12.9 11.6 13.2 11.7 10.5 9.2 real
Cannington 520m 4,424 18.5 14.8 10 14.8 9.7 9.3 9.2 real
Devonport At Hobart 461m 500 18.2 15.6 9.4 12.6 9.8 9 9.2 real
Mandurah 302m 2,248 16.8 13.4 9.5 15.2 12.7 11.9 9.2 real
Horsham 485m 1,732 18.5 15.5 11.4 11.5 9.4 10.2 9.1 real
Maitland 400m 2,410 17.6 14.4 11.8 11.3 8.5 9.5 9.1 real
Taree 300m 1,608 18.2 15 11.5 12 10.6 9.1 9.1 real
Muswellbrook 336m 710 15.4 15.8 14.1 11.4 6.8 10.8 9 real
Betdeluxe Capalaba 366m 5,807 12.8 11.7 10.8 11.3 8.9 12.8 8.9 real
Bulli 472m 712 17.6 15.7 9.3 11 8.7 11.5 8.9 real
Dapto 297m 1,818 19.3 13.8 10.8 11.7 11.2 10.5 8.8 real
Mandurah 400m 2,472 18.5 14.1 11 11.1 9.9 9.7 8.8 real
The Meadows 600m 3,880 18.2 15.5 12.2 12.6 11.4 9.4 8.8 real
Bundaberg 460m 1,755 18.1 16.1 12.3 13.2 10.5 9.4 8.7 real
Healesville 340m 4,088 10.7 11.7 9.8 10.7 10.1 13.4 8.7 real
Bendigo 500m 5,555 18.5 15.3 13 10.6 9.9 10.3 8.6 real
Lismore 420m 689 17 12.6 8.4 12.3 9.9 11.2 8.6 real
Geelong 457m 5,697 16.8 12.8 9.2 9.3 11 10.9 8 real
Traralgon 450m 627 16.1 15 12.1 11.8 8.1 11 8 chance
Richmond 330m 1,835 16.9 15.3 13.7 14 10.8 9 7.9 real
Shepparton 650m 615 17.4 14.8 11.5 12.5 11.2 11.2 7.8 chance
Gosford 388m 3,072 17.3 14.1 12.9 11.1 9.6 10.3 7.7 real
Warragul 460m 9,343 17.6 14 11 10.8 9.9 11 7.7 real
Warrnambool 332m 806 16.6 12.8 12.4 11.8 11.2 8.9 7.7 real
Ladbrokes Q1 Lakeside 457m 1,040 16.5 16.7 12.6 12.1 9.1 11 7.6 real
Cranbourne 699m 640 14.8 13.3 12 14.8 7.3 11.7 7.5 chance
Traralgon 658m 412 16.5 14.8 14.1 9 10.7 11.7 7.5 chance
Mandurah 405m 4,048 17.7 14.5 10.3 13.4 11 11.4 7.4 real
Albion Park 710m 413 15.7 16.5 13.1 15.5 9.7 10.4 7.3 chance
Cranbourne 520m 9,314 17.5 13.7 10.5 11.8 10.3 10.2 7.3 real
Bendigo 425m 13,152 16.6 14.6 11.4 12.2 9.4 10.1 7.2 real
Sale 440m 11,319 15.9 12.1 10.6 11.8 9.4 11.4 7.2 real
Temora 330m 2,166 16.7 14.5 11.1 9.5 9.6 10.7 7.2 real
Bendigo 660m 451 14.2 16.4 14.6 12.4 9.8 9.3 7.1 chance
Devonport 452m 1,290 16.4 15 11.3 11.8 10.2 11.2 7 real
Ladbrokes Q Straight 350m 624 17.3 13.6 10.4 12.2 10.4 12.2 6.9 chance
Geelong 460m 7,765 16.3 12.4 9.6 12.4 9.5 12.3 6.8 real
Gosford 515m 1,248 15.3 15.5 12.2 13.1 8.7 9.4 6.8 real
Warrnambool 390m 8,293 16.4 13.9 12 11.6 9.7 10.9 6.7 real
Bulli 400m 1,741 16 16.2 10.3 12.8 9.8 9.6 6.6 real
Warragul 400m 12,669 16.4 13.7 11.8 11.3 9.8 10.7 6.6 real
Devonport At Hobart 340m 498 16.5 12.4 10 16.5 10 12 6.5 chance
Grafton 450m 1,314 15.1 15.4 9.7 12.3 9 10.3 6.4 real
Ballarat 390m 10,674 15.7 14 11.5 13.4 9.5 10.8 6.2 real
Geelong 400m 11,071 14.3 14.7 11.8 11.8 9.3 10.9 6.1 real
Gunnedah 340m 2,868 16.6 13.2 10.7 10.5 10.5 11.4 6.1 real
Richmond 320m 3,390 16.9 14 12.5 11.9 10.8 11.2 6.1 real
Sale 435m 2,671 14.4 12.5 11.3 12.1 9.2 12.4 6 real
The Meadows 730m 1,182 14.6 15.9 11.7 14 11 10.3 5.6 real
Temora 457m 909 15.3 13.2 11.8 12 9.8 10.1 5.5 chance
Richmond Straight 324m 2,632 14.2 13.1 11.7 11.1 9.6 12.3 5.4 real
Grafton 350m 3,046 14.4 12.9 11.4 12.3 10.5 9.7 5.3 real
Hobart 461m 2,109 15.1 14.5 11.7 14.6 9.8 10.3 5.3 real
Shepparton 450m 10,913 15 12.8 11.8 12.2 10.2 11.1 5.2 real
Shepparton 390m 10,180 15.4 13.9 11 10.9 10.4 11.2 5 real
Ladbrokes Q1 Lakeside 390m 884 15.3 10.5 13.7 13.8 10.9 11.9 4.8 chance
Healesville 300m 8,323 14 13.8 11 12.8 10 11.3 4.6 real
Ladbrokes Q Straight 300m 737 13.6 15.2 12.6 13.3 10.6 11.8 4.6 chance
Healesville 350m 9,184 14 13 11 12.5 10.6 11.6 4.4 real
Bet Nation Townsville 380m 5,459 14.5 14.5 12.3 13.3 11.4 10.6 3.9 real
Hobart 340m 1,414 14.9 13.9 11.5 13.2 11.9 11.4 3.9 chance
Ladbrokes Q1 Lakeside 352m 1,034 14.9 11.6 11.9 13 12.2 11.9 3.6 chance
Sandown Park 715m 1,729 13.4 13.4 11.9 12.6 11.2 12.4 2.2 chance

14 of the 176 combinations came back within chance. They are listed too, marked chance — a test that only reports its positives is not a test.

Check it yourself

This page is the output of an open-source command-line tool. It downloads results through the API with your own key, caches them, and computes the table above. A free key reaches a rolling seven-day window — enough to watch it work; a live key reaches the archive.

git clone https://github.com/GreyhoundAPI/greyhound-racing-trap-bias
cd greyhound-racing-trap-bias
python -m gtb
An earlier version of this tool got the statistics wrong. It divided the gap between best and worst trap by the standard error of a single trap’s percentage, which overstates significance — badly on small samples, so the thinnest combinations rose to the top looking most convincing. Tested against generated races with no bias at all, it called 43% of them significant. The chi-squared test that replaced it calls none of them. Every number here comes from the corrected version, and the tool will tell you the same.

This is one free endpoint

The table above comes from results alone. Live Plus adds per-dog and per-trainer statistics — how a particular greyhound runs from a particular trap at a particular track, which is where a tendency becomes a prediction.

See Live Plus Get a free key