Patricia, the only time a bagger will affect you is if you play credit games against them (either MP Creds or Skins for creds) - or if you try to compete in big ticket RG's (and seeing as you are at Master level, the baggers are very numerous in the top billed comps at that level).
For the MPC's and Skins for credits, just use some caution and look out for funny behaviour up front. Every now and again I set up MPC with whoever's out there, and one time in the lobby before the game, I suggested 300cr for the challenge, his response was "I only play for 1000cr of more.....", I was okay for 500cr and suggested that, he had the exact same response. Now, he might not have been a bagger, but that is just a tad suspicious - I understand the cost/benefit in terms of ball use, but anyone who is that inflexible should tweak your "something is not right" response. So I did not play him.
Another thing to watch for is the inflexible on the course guy - will play MPC with anyone for example on BPB F9 but nowhere else - not necessarily a bagger, but you need to check their score history on that course - there are few TL's out there that only play BPB or St Andy's. Believe me, they know every inch of those greens and will slaughter you unless you are lucky.
Lastly, add a lot more suspicion to any opponent playing for creds who is lower tier than you, and with hardly any ranked rounds in. Only way for a bagger to maximise his return is to avoid ranked rounds like the plague.