I paper tested this with the laying the 0-0 system that was talked about on PL about a year ago (THink you get odds of about 1.08 a go) and only made it to 6...
The problem was that it was only the live TV games that were covered at the time so the market was limited - that's my excuse anyway!!!!!!
Speaking of dead certs the last time I looked into the above
Skybet were offering markets on players not to score....Crap odds like 1/20 or so but you could put them in an acca and that interested me at the time but I never got involved...
Best of luck to you Muze!