I think I see what you're saying here.
George he's asking if you've ever looked at wagering the Asian Handicap of +0.5 instead of just the single play on the underdog. This wager is essentially that the dog won't lose, and still wins/pays as long as the dog wins or draws. It'd be interesting to see what the record would be for these, as the plays that do lose many times are still close and end up drawing. Of course the payout isn't near as high for these type of wagers when the dog actually does pull off the upset and win (especially for big upsets like West Ham over the weekend), but it makes up for that by mitigating the risk in that it still cashes if they play to a draw.
It's basically a wager on the dog either winning or drawing (or saying it another way 'laying the fav' and betting they won't win). Certainly worth investigating to see if there's any significant difference in profits/bankroll growth!
Hope I understood you correctly Plukjee, please let me know if you meant something else my friend!