Systems as a guide , form and ratings as the decideing factor. Im getting much benefit from a Rem Plante book - suggestion is that we should look more at lengths away from the winner rather than its position

You've hit the nail on the head!!

So many systems rely on finishing position, rather than how far from the winner the horse finished.
In a blanket finish, a horse can finish 7th or 8th, yet be only 2 or 3 lengths from the finish.
Yet, many systems will eliminate a horse who hasn't finished in the top 4.

Conversely, a horse may have finished 2nd , yet was beaten by 4 lengths.

Out of the two above examples-which was the better run?

below is the first 12 placings in the AJC Doncaster of 2005.

Which horses were failures, and which ran well?
you be the judge.

PL SP No Horse (Trainer) Bar Kg O/A Jockey Margin
1 9.50 7 PEKALAN (Albert Stapleford) 7 53.0 R S Dye
2 8.00 11 SILVER FUN (Gwenda Markwell) 14 53.0 D Beadman 1.3
3 61.00 13 FULL ON MAGIC (Louise Munce) 18 53.0 D Beasley 1.4
4 26.00 8 VALADEZ (Gwenda Markwell) 17 53.0 L Cassidy 2.0
5 21.00 1 PRECISE TIMING (Ross Stitt) 12 58.5 L Beasley 2.2
6 (F) 5.00 3 FIRE AT WILL (Barbara Joseph) 10 57.0 G Boss 3.9
7 26.00 14 RAMINCO (Paul Perry) 4 53.0 3.0 T Uchiyama (a) 4.1
8 10.00 4 RED ROBERT (Gratz Vella) 6 54.0 M A Cahill 4.2
9 31.00 9 MARFOO STAR (NZ) (Debbie Prosser) 11 53.0 D Nikolic 5.6
10 31.00 6 SERPENTINE (Robert Murrell) 9 53.5 J Ford 6.8
11 19.00 16 NORTHFIELD DRIVE (Alan Scorse) 15 53.0 B Stanley 7.2
12 8.00 2 DIAMOND SUN (NZ) (Darren Smith) 13 57.5 C Brown 7.3

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why gobble with the turkeys, when you may soar with the eagles!!