Okay so lets expand on the track condition as a possible filter using data to date.

Total results for all data to date up to and including Thurs 12/5:

OPTION 1 (Courier Mail 3rd fav >= 6.00, 4th fav >= 8.00 and 5th fav >= 10.00)
Return 756.10
Outlay 570.00
Profit $186.10
POT% 32.65%

OPTION 2 (Courier Mail with races dropped where 5th fav is same odds as 6th fav)
Return 582.80
Outlay 320.00
Profit $262.80
POT% 82.13%

OPTION 3 (same as Option 1 but using WEB2BET site)
Return 121.00
Outlay 102.00
Profit $19.00
POT 19%

Now If I separate these by track condition of HEAVY, SLOW, DEAD, GOOD we get:

HEAVY OPTION 1
Return 34.00
Outlay 47.00
Profit -$13.00
POT% -27.66%

HEAVY OPTION 2
Return 34.00
Outlay 35.00
Profit -$1.00
POT% -2.86%

HEAVY OPTION 3
Return -
Outlay 12.00
Profit -$12.00
POT -100%

SLOW OPTION 1
Return 152.20
Outlay 101.00
Profit $51.20
POT% 50.69%

SLOW OPTION 2
Return 109.30
Outlay 57.00
Profit $52.30
POT% 91.75%

SLOW OPTION 3
Return 62.40
Outlay 23.00
Profit $39.40
POT 171%

DEAD OPTION 1
Return 389.00
Outlay 321.00
Profit $68.00
POT% 21.18%

DEAD OPTION 2
Return 300.40
Outlay 172.00
Profit $128.40
POT% 74.65%

DEAD OPTION 3
Return -
Outlay 22.00
Profit -$22.00
POT -100%

GOOD OPTION 1
Return 180.90
Outlay 101.00
Profit $79.90
POT% 79.11%

GOOD OPTION 2
Return 139.10
Outlay 56.00
Profit $83.10
POT% 148.39%

GOOD OPTION 3
Return 58.60
Outlay 45.00
Profit $13.60
POT 30%

Sample data for OPTION 3 is only 3 days long so little can be gleaned at this stage from that data.

Looking at this now, maybe there is something in dropping HEAVY tracks?

I am hoping to get this sample data to a full month where I have checked at least 3 - 4 days per week to a sample data range of 20+ days of racing. Then hopefully I will be able to get a good idea of some effective filters to apply.

Heck I may even open an online account and put a dollar or 2 down!