I'm worried about getting a bad teacher?

I'm going into third year at secondary school (Scottish) and the school is tiny-only two history teachers. I had one in first year who literally spent all the time talking about things completely irrelevant, and then would give us a test, which I failed. In second year we got a teacher who explains the work well, asks you what you would like to revise before tests, and we all did brilliantly-I got the top marks. But I'm worried about which teacher I'll get after the Summer-I really can't do well with the first teacher, I need a teacher who actually explains the work and has high expectations-what do I do if I get the bad teacher?