What is a system?

[the shadow]

I have heard that all underdogs in all major sports cover the closing line at about 50.6% of the time over the last 20 years. (don't know if that's true). That's probably a 100,000 games, who knows? However, if I were bet my buddy on every game starting now against a no vig line, do you think I would win in 20 years by taking all dogs. If so then history is repeating itself. Or will all fav's cover 50.6 % the next 20 years? Would this be called a system? No handicapping, no models etc.
Does any know if that 50.6% stated above is close to being correct?

[the shadow]

sorry for the typo's. I am a saluki fan!

[Joe Dogs]

Here,s something to think about....If you would have blindly bet $100.00 on every dog in baseball,in the month of April,since 2004

You would have netted a profit of $13,000.00

Market inefficiency in the start of the season.

[hutennis]

Could it be simply variance?
Is not it a much simpler explanation than "market inefficiencies"?

Could it be that you just fishing for data?

[chopperocker]

a system is a trend based betting strategy involving an entire league or association. if you dig deeper you will find stronger trends based on moneyline price, point spread, home/away, coaching staff... etc.

heres a system - play AGAINST home favs of -3 in NFL. they only cover 37%. and another - play on road favs of a bye in NFL 26-7-2 ATS.

heres a trend - John Harbaugh Ravens are 8-3 SU and 3-7-1 ATS as a home fav vs divisional opponent and 18-0 SU and 14-4 ATS as a home fav vs non-divisional opponent.

[mathdotcom]

A system is taking the Yankees on Tuesday but only if it rained on Monday and if the starting pitcher is black and the leadoff hitter is balding.