"Treat with caution all these theories and statistics about barrier positions. The barrier position is just one factor you have to consider and you should not give it undue importance. A good horse, well weighted and well ridden, can overcome the disadvantage of a wide barrier.
"While some punters refuse to back horses drawn wider than 8, 12 or 15, depending on the fanaticism of their opinion, I have backed scores of winners drawn out in no man's land. One of the most memorable was Citadel at 100/1 in the 1974 Epsom."
On the subject of how much ground horses lose when racing wide, Don Scott has this to say: "One expert on wide running has calculated that ... the actual ground a horse loses by running two wide on the home turn at Randwick is 1.42 metres (56 inches), or just over half a length. According to him, you have to compensate a horse two wide 1kg, three wide 1.5kgs, four wide 2.5kgs, 5 wide 3kgs, and so on."
Scott himself says his own compensations for horses running wide “are less than the actual ground lost." In his book, he lists such compensations for wide running under two headings-‘For Wide Running On Early Turns' and 'For Wide Running on the Home Turn.' For example, let's say you had a horse drawn in a wide barrier and at the first turn he was caught five wide on a track rated fast. In Scott's estimation, that would call for a compensation factor of 1kg.
Let's say, also, that the same horse was six wide when negotiating the final turn; Scott would allow a compensation factor of 3kgs. Therefore, when assessing this particular horse's final race rating for a future race, Scott would give it a bonus of 4kgs for that wide running effort.
There is no doubt, then, that barrier draws do have a big role in determining whether a horse can win or not-but probably not such a dominant one that you can afford to make sweeping assertions. Therefore, you cannot dismiss any horse from calculations merely because it might have drawn barrier 18 in a field of 18.
A famous American turf expert, Lou Holloway, once wrote: "You can't blithely accept statistics or the law of averages in racing, because each race is a separate entity, with different variants. So a horse drawn out wide in one race might lose, but in the next race, in a completely different set of circumstances, another horse coming from the same barrier in the same size field, will win."
Scott dissects each major city and provincial track, in all States, and allows various penalties for horses racing from wide barriers. If you use these, in conjunction with your own knowledge about a horse, you should be able to accurately 'track' how much a barrier will affect any individual horse.
For example, you may be looking at an early-speed horse drawn in barrier 15 in a 1200m sprint at Randwick. You know that this horse explodes away from the barrier, and you reason that it should possess enough pace to lead in the first 100 to 150m. So then you look at Scott's charts and you find he has allowed a 1kg penalty for a horse drawn 15 over 1200m at Randwick.
You now have to decide if you should penalise the horse that 1kg, or perhaps reduce it to a half kilo, or even do away with it completely. You may feel the wide barrier is no disadvantage, given the horse's ability to 'ping' away smartly and display early toe. Or you may decide that even with the early speed, the wide barrier might mean the horse will have to be asked to go just a little too hard too early, and therefore will have much less stamina in reserve when the chips are down in the testing final 300m.
My own observations are that horses drawn between 1 and 7 should be suitably drawn, unless you can make out a case for a slow beginner in a sprint being chopped off from, say, barriers 1 to 3. Against this, you have to assess whether it is an advantage for the horse to be axed out of the early rush, given that it's a late closer anyway.
Horses drawn between 8 and 11 are getting into the 'midways' range, where you have to begin giving some consideration to penalties, depending on the distance of the race, and the shape of the track, taking into account the distance between the barrier gates and the first turn, and also taking account of each horse's racing style.
Once you get from barrier 12 outwards is where you strike more and more imponderables. I think it's essential that those serious punters possess Don Scott's Barrier Charts, and that they use them as reference guides at least. You don't have to accept the penalties he lists at face value; instead use them as a tool for your form study and change them as you see fit.