Sports and markets + rounding bets

Which sports and markets will u prefer?

I had an absolutely amazing day on grand slam wednesday, but thursday was doom day. In everything! Went -1.500 on one day, and it hurts. Especially because i started rounding my bets to 50 instead of 25.

And last but not least. What are ur experience with rounding ur bets, and what do u suggest with a current bankroll at 1.800?