OK here's one for you all.

I love reading the posts on this system part of the website, because systems are great. They're the promise of the pot of gold, the holy grail, the "discovery".

"EUREKA!" you cry as the set of results come in and it's in profit.

Then comes the dreams of sitting on a yacht, sipping champagne as you listen to your bets roll in, and of course the obligatory large mammoried blonde reclines next to you.

That is - of course - the illusion.

But I did read with interest the thread on the 4yo system recently, and it occurred to me, what's a good sample size for a system?

If for example you find a system that's winning 20% on turnover, then you're flying, but how reliable is that 20% for future forecasting? How many selections do you need in your sample size to be able to confidently say that the trend will continue?

Also, if the dividends of a system are calculated from SP, what improvement can one expect when using a variety of methods and choosing the best in the real world, ie products like maxi-div and best fluc and betfair and austote. If you're in front of your computer ten minutes before a race and you have all those at your disposal (though admittedly top fluc is not available ten minutes before), then surely you're going to average better odds than just SP.

Thoughts, peoples?