During a downswing I just had, I thought I might have been raising too many marginal hands from MP (I play 6 max) and thought that I should tighten up my raising standards from the first half of the table. To make this easy, I sorted my hands by VPIP, to group all the ones I regularly play and checked if there were any hands I played regularly that I was losing with. I was a consistent loser with KJ, KT, T8, QT, QJ, these were all hands I regularly played and opened with. I was a net loser with them. So I stopped opening them and trying to steal blinds with them from too early positions. I wasn't coldcalling with them, that wasn't the problem.

Try it out, sort your hands by VPIP and see which ones are in your regular playing repertoire and are losing you money. For the 50K hands that I was playing/running fine and goot, these slipped under the radar but were just weighting my WR down.