Thanks for the responses everyone.
Fidibus, it sounds like your getting closer and closer to the Holy Grail of Trading, that's wonderful

Although my own focus is on horse racing its good to see someone excelling (sorry about
that

) in such a large volume market and up against traders who live and breath football. Unfortunately my choices are limited to horses in play due to Australian laws. Please keep us posted as to how your strategy develops.
GMBing, yes, I have also found the biggest problem with auto lies in defining rules for opening and exiting trades. At the beginning of this project I sat by watching Guardian over many nights in order to manually correct and cancel bets that could leave me liable. Semi-auto appears to be the safest method, short of writing 20-30 rules in an attempt to cover most possibilities.
Peter,
'
there were times I had to switch the screen off as I can see how much was being fired into the market!'
'Im not sure about the football (as there is plenty of liquidity), but in play on the horses I hit a point of diminishing returns. If you plot a graph over many markets you will be able to tell at which point the stakes were at the optimum.'
From what I have read, it seems running automation opens you up to some sort of ethereal 'grey' world where tests cannot always be repeated, practice mode does not mirror reality and larger stakes just aren't possible. As my strategy is based on seeking value on selections I just hope the volatility that gives rise to these values doesn't start to diminish. Leaving aside longer 3m races, I have noticed many Aust. races often seem to lack the odds fluctuation ranges of UK racing.
Jon