Horse racing draw advantage bias
Both the Rowley course and the July course are very wide and are sometimes split in half using a temporary running rail.
Races are then run on either the Low half of the course, or the High half of the course.
At present, there is no indication in race returns of this course splitting.
I would guess that in general, results showing Low positioning of the stalls will mainly be run on the Low half of the course, and races with stalls positioned High, will mainly be run on the High half of the course.
Results with stalls Centre could have taken place on either the Low half of the course or the High half of the course.
The chart below covers all races on the straight 5F course.
As described in the Racing Post's "Top Draw" feature, the stalls can be positioned in 6 different places due to course splitting.
High, Low and Centre on the Low half of the course, and High, Low and Centre on the High half of the course.

Horse racing draw advantage bias NEWMARKET (Rowley) 5F
Stalls positioned HIGH (H), LOW (L), Centre (C)

Link to course and distance menu

WINNING STALL NUMBER
No

of

R

U

N

E

R

S

  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
8 C H            
9 L H         H    
10                 LC  
11             H   LL H  
12     L                   
13   L C        

L

     HL    
14 L                 L          
15                          H      
16                 H   H   H      
17               H                  
18             L         H            
19             H   L                    
20       H                                
21 H     L                                  
22                                            
23     H                         L               
24               H   H                            
2 2 1 1 0 0

<--Good or better -->

 1 0 2 2 3 0
12 10

Copyright © 2003 [Howard Hutchinson]. All rights reserved.

Not many results here.
There is a very good 6F pattern with stalls positioned Low.
It could be that a faster strip of ground close to the Low rail is more effective in the longer races of 6F.
In these 5F races, on good or better going with stalls Low, stalls 1 to 4 won 5 of 10 races.
In 2006, on good or better going, both winners started from the Top half of the draw.
In races of 8 - 15 runners, stalls 1 - 4 won 4 of 7 races 66% but 7 races is a very small sample.

These races are worth keeping an eye on if the stalls are positioned Low on the Low half of the course, nearest to the stands but we need more results to be sure of any advantage.

On good or better going, High positioning of the stalls appears to produce nothing of note.
Throughout this chart, the highest stall has won 0 in 35 races on any type of going, or any stalls position.
On good/good to soft in places or softer going, stalls High, stalls 1-4 won 4 of 5 races but 5 races is a very small sample.
With the stalls positioned High, these are the stalls towards the Centre of the course, or at least away from the High running rail.

2006 results :- 7-11 (H), 9-11 (L), 9-14 (L), 16-23 (L)

2005 results :-  1-9 (L), 7-9 (H), 9-11 (L)

2004 results :-   1-14 (L), 11-13 (H), 13-16 (H).