mattio, I note that you said you're still looking for the ideal system. "Is it possible that you're so close to the industry that your thinking is "blinkered" (pardon the pun!), and skewed to placement of horses, and optimising conditions for your horse to perform at it's best ..... that you've completely disregarded the notion that dividends are crucial, and the better dividends come from going against the crowd (within reason of course), and the lousy dividends come from following the crowd?"

At the end of the day Mattio is making money. Thats the name of the game.

Barny you can use whatever filters you want for as ling or as long as you want mate, like I said this post was not to have a go at your filters. My goal for the post was to make people aware that basically all filters are a result of some kind of backfitting and to say that a filter is not backfitted is not true because "backtesting" is how we come up with our filters.

As for my filters being the bees knees I am pretty sure that I never said that, they are logical and they work for me which is all that matters.......and I never once said any of them were "magical" either.

Let's look at your filter of $4 and $30.....why did you choose those numbers, why didn't you choose $5 and $25, or $4 and $20? Was it because you found that you got better results from that price bracket? That is fine, it works for you and I can't recall bagging it anywhere in my post.

Not betting in races with first up horses (or first starters) is one of the most logical filters around, there are so many possible surprises you can get from first up horses or first starters and since there are thousands of races each year I can pick and choose whatever races I like......it works for me and that is all that matters.

Haha, I like that you actually think those are the only filters I use and I never said I use them all in the same system. When you assume things Barny you just make an ass out of you and you

So, to sum up mattio, you've got logical filters that aren't backffited ...... can you actually hear what you're saying ??

So you only use logical filters that aren't backfitted. Examples you give are - not first up - "d" - "t" - Metro run last start. For starters, I don't for the life of me know how you can suggest "d" and "t" are not backfitted. They are part of historical data (like a lot of other filters) which we use to predict future performance .....

Your filters, you suggest represent about 1%, because as you say every other filter is a result of a back test. So to find your filters we have to look for similarities to "d" and "t" etc. Days last start ??, nah can't be as some horses back up, some need a couple of weeks off. It's too individualistic. Race Prizemoney - ??, Weight ??, Barrier - that's one of them for sure. So we're looking for at least another 2 maybe 3 filters to bring a LOT of 20% into a POT of 20% (it's gotta be that much), and filters that aren't backfitted.

The difference between filters that are backfitted, and mattio's filters that aren't backfitted is - mattio's perception of what backfitting really is. I'm actually on his side in this and having thought about what he's saying, it's exactly the same path as I'm trying to go down. I do have a few good systems, and I believe they're logical (yup they contain filters that are backfitted, but I don't change them), but I also see the sense in what mattio's trying to convey here.

Vortech, everyone wins the races, surely you know that.

Or they make out they do.

Barny, I don't think mattio is saying his aren't backfitted at all, he's saying the following:

If you have a bunch of data that your backtesting on that goes back say 5 years. You've added in some rules, such as the following:

Days Last Start - between (and inclusive) 5-24
Win Strike Rate - above 24.635%
Placing last start - 1
Placing 2nd last start - 5
Won at track 3 times
Won at distance 3 times

^^ Clearly the above is backfitting, your changing numbers to specifics to maximise your POT, which is great to show a high POT but the chance of that perfect storm repeating in the next 5 years is minimal at best.

Mattio (i think) is simply saying that your aim should be to have logical filters that aren't specified down to minute detail so that you avoid substantial backfitting. So in reference to the above example your filters may be this instead:

Days Last Start - between (and inclusive) 7-21 (logical as its ran on the same day previously, i.e. not starting on a saturday now and some random weekday previously)
Win Strike Rate - above 25% (obvious one, you can't backfit to a specific % its just illogical)
Placing last start - 1 (fine to leave as 1 if you want a last start winner, nothing wrong with this filter)
Placing 2nd last start - 3-x (instead of specifying it had to have finished 5th last start, it needs to be a range otherwise its again being too specific to your backfitting)
Won at track 3 times (you could possibly use this filter but i'd suggest saying won more then 3 times at track, as saying exactly 3 times is too specific again)
Won at distance 3 times (you could possibly use this filter but i'd suggest saying won more then 3 times at distance, as saying exactly 3 times is too specific again)

I think there is room to have maybe 1 filter that is more specific that gives you the edge, but as soon as you start tinkering took much its just over-backfitting too your data. I think thats all mattio is trying to get at Barny, he's not having a shot at you and neither am I, were just suggesting people are careful with how they approach creating a system.

evajb001, mattio picked me up on a few things, one the $4 to $30 SP. Geoff Murphy only backed his horses if they were better than $4. He figured that with his S/R he was sure to win. On this very forum, many suggest they don't bet under $4. I don't like to take short odds so $4 it is. The $30 seemed a fair cut off point too. But that wasn't good enough for mattio, this was backfitted says he. He doesn't "know" how I arrived at any of my filters or how long they have been tested and how they've been tested. One system shows a brilliant POT each and every year over 12 years in both Melb & Syd, it doesn't have many selections each year tho', so the naysayers on here will tell me it's unproven. The race type filter reduces the number of selections down quite dramatically. Another system has filters including 1-4 last 5 runs, > 2 runs since spell, SP $4 to $30 and a couple more filters ..... too many filters ?? I'm looking here for a lightly raced horse with good recent form with at least a couple of starts from a spell in the Metro Area. Don Scott says when you find a good young horse down in the weights you should bet heavily on it. This system is nothing more than putting one of Don Scotts favourite type of wagers on paper. Perhaps my best system is one that looks for overseas, interstate, NZ horses with a decent Win S/R. Mentioned this one quite a few times too and over the Spring Carnival.

mattio, I believe, as I've posted is too close to the action, and he's concentrating on giving his horses the best possible chance of winning without realising that it's the dividends that allow you to show a profit. The better divvis come from going against the crowd and the worse ones from following "won at track", "won at distance" ..... everyone is on those filters, have been for ages and will continue to do so. All that does is give you an overbet horse, no matter what other filters you put in.