Horse racing draw advantage bias.  Sandown 5F  3 Charts
Stalls positioned HIGH and Centre. (See Stalls LOW on chart below).

Link to course and distance menu   Down to False Rail analysis

WINNING STALL NUMBER

 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22
No

of

R

U

N

E

R

S

8 1 1 11 1   1 111 111
9 1       1 1C 11 1  
10 111 1111 11 11 111 11   1111 11 Stalls positioned HIGH
1997 - 2006
11  1 11 1     1 11 1 11 1 11
12   1 11 1 11 11   111 11 1 111111 11
13     1 1   1 1   1 11   111 11
14 1 11    1 1 1 1   1   11 1 11 1
15      1   1 1       1 11     1  
16 1           1               1  
17 1 1              1   1   1   1 11  
18               1                    
19             1                        
20                     1       1   1   1  
21                                          
22                                            
7 9 3 4 4 7

<--Good or better -->

6 11 10 4 18 7
29 53

Copyright 2005 [H Hutchinson]. All rights reserved.

A theory keeps surfacing concerning soft ground in these races.
The theory is that when the ground is on the soft side of good and the stalls are placed on the High side of the course (the far side), High numbers are favoured.
The theory is :-
the softer the ground, the greater the advantage.
Historically, results in these races have never justified such advice. 

On going described as good/good to soft in places or softer :-
The Top 6 stalls won 22 of 42 races
Stalls 1 - 6        won 19 of 42 races.
The Top 1/2, Bottom 1/2 split is Top half 21 wins, Bottom half 20 wins.
One other winner drawn 9 of 17 was dead centre.

By far the most reliable and consistent pattern here is produced by results on good or better going.
Looking at the chart, it is obvious that in races of 8 - 10 runners, results are spread across most stalls.
In races of 11-14 runners the           Top 6 stalls won 32 of 46 races 69%.
In races with 15 or more runners the Top 6 stalls won 9 of 14 races  64%.
Combining the two :- 
Good or better going, stalls positioned High, 11 or more runners, the Top 6 stalls  won 41 of 60 races 68 %.
On good or better going in 2006, the Top 6 stalls won 10 of 14 races, and 8 of 11 races under those conditions.
This course and distance was relegated to the Stalls To Follow B list for 2006, due to the use of a false rail, introduced during 2005.
A false rail has been used in these races during 2005 & 2006 to narrow the course, but after a short analysis of 2005 and 2006 results, it appears that so far, the false rail is not having an adverse affect on this draw advantage.
Down to False Rail analysis

2006 results :- 2-10, 5-10, 6-10, 1-11, 9-11, 9-11, 11-12, 11-12, 4-13, 9-13, 12-13, 12-13, 12-13, 13-13, 2-14, 11-15, 9-17

SANDOWN 5F
Stalls positioned LOW See chart above for High positioning

WINNING STALL NUMBER

 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22
No

of

R

U

N

E

R

S

8         1      
9   1 1   1 1      
10               1     Stalls positioned LOW
11         111            
12 1                    1  
13            1         1    
14                             1
15                                
16                                
17                                  
18                                    
19                                      
20                                        
21                                          
22                                            
1 1 1 0 4 1

<--Good or better -->

0 1 2 1 0 0
5 4

Copyright 2005 [H Hutchinson]. All rights reserved.

 

 

 

All races of 15 or more runners over this course and distance during the last 9 seasons have had the stalls positioned High.
There are not enough results here with stalls Low from which to draw any reliable conclusions, BUT :-
On good or better going, stalls 1 to 6 won 8 of 9 races 88%.
Note that all those races had less than 13 runners.

On good/good to soft in places, or softer going, the Top 7 stalls won 4 of 5 races.
The Top 7 stalls are the cells highlighted in blue, plus the next cell to the left in white.
The last time the stalls were positioned LOW in these races was July 3rd 1999.


Sandown 5F false rail  Results 2005 and 2006 to July 8th
Stalls positioned HIGH

The running rail for the meetings July 1st/2nd, 20th/21st, and 27th  2005 was moved in by approximately 3 yards on the High side of the 5F course.
The official explanation for this was that it was done "to provide fresher ground".
Using the Racing Post's Video Form facility, I looked at past races to see when false rail was used.
These were the results of races for older horses 2005 and 2006 to July 8th.
Videos weren't available for 2004, and now can only be viewed by subscription.
Y = False rail in use, N = Not in use.
As usual, red results indicate going good/good to soft in places.

WINNING STALL NUMBER

 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20
No

of

R

U

N

E

R

S

8   y y         n
9         n         3yr olds and older
2005 - July 8th 2006
10   ny   y y y        
11                      
12           n         yy nn
13                 y     y n
14                     n   y  
15     n               n        
16 y                              
17   n                              
18                                    
19                                      
20                                        
1 3 1 0 2 2

<--Good or better -->

2 3 1 0 3 2
7 8

Copyright 2005 [H Hutchinson]. All rights reserved.

The Bottom half, Top half split is almost even, 7 wins against 8, with one other winner drawn dead centre (5 of 9).
On good or better going, the Top 6 stalls won 11 of 16 races 69%.
With a false rail, the Top 6 stalls won 7 of 10 races 70%.
Without a false rail, the Top 6 won 4 of 6 races 66%.
On good or better going in races of 11 or more runners, the Top 6 stalls won 7 of 10 races 70% (with or without a false rail).

On going softer than good, there were 3 wins from stalls 1 to 4 and 4 wins from the Top 5 stalls.

Initially, in 2005 stalls 1 to 6 won 4 of 4 races with the false rail in use, results  2-8, 3-8, 6-10,1-16 on the chart above.
Due to those results, I relegated this course and distance from the Stalls To Follow list for 2006, and awaited further races.
After that initial scare, the false rail appeared to have negligible effect from a draw advantage point of view.
These are the 2006 results since the analysis above was uploaded during 2006.
These results are not on the chart, and may or may not have had a false rail in use :-

Jul 26  Good-firm/firm 6 - 10  25/1 ( 5th Top stall)
Jul 27  Good-firm/firm 11 - 11  4/1
Aug 16  Good-firm 12 - 13  11/1
Aug 17  Good-firm/firm 9 - 11  11/2
Aug 25  Good/good-firm 1 - 11
Aug 26  Good 4 - 13
Sept 8  Good-firm/firm 2 - 14
Sept 13  Good/good-soft 9 - 17

2005 results :-   2-8, 3-8, 8-8, 5-9, 2-10, 4-10, 6-10, 6-12, 11-12, 12-12, 12-12, 13-14, 11-14, 3-15, 1-16, 2-17

2006 to July 8th :-  2-10, 5-10, 11-12, 9-13, 12-13, 13-13, 11-15

Underlined results were races with a false running rail, 3 yards in from the normal High rail.