What do you specifically do you think that has put and kept you in the black?
Good Luck Dougie? 
I think for me it's strictly "spot playing" that's allowed me to do well. After years of getting beaten to a pulp betting 10 races on a 10 race card, I limit myself to about 7-8 wagers per week. I know someone out there can probably hit 10 races on a 10 race card. But not me. Ever. LOL! My success rate has blossomed a lot by betting stakes races and high priced allowance races with the throughbreds. Cheap races always seem to be so inconsistent. In cheap harness races, it seems that they "take turns" winning. That screws the bettor and allows them to rarely run the same two races in a row. So I'm kind of sour betting that game. I read the throughbreds entries daily and follow up reading a lot of "expert" opinions from handicappers on various sites. I also make "trip notes" for every race I bet which enables me to streamline my handicapping. I love the meets at the Spa, Keeneland, and Colonial Downs. So i'm apt to wager a little more on races I like there. But the most important aspect of me is money management. To many players "chase" on a bad streak. That makes it worse. They keep betting hoping to "get even". Best to let that losing wager go, regroup, and load up on a race that shows value and a better return the next time. I having a pretty good year so far. I'll just keep on plugging away.