When I slap, I have my hand roughly at right angles to the strings, and my thumb sticking out maybe 30 degrees or so and level with my hand. When my bass teacher slaps, his hand is at about 45 degrees to the strings, and his thumb 45 degrees from his hand, so running roughly parallel with the strings. He also sticks his thumb forward slightly. Using my technique, I find it difficult to slap the third string and get a clear note, but with my bass teacher's technique I can't do anything. I think his way is technically better, but is it worth actually trying to learn a whole new slap technique when I'm slapping quite happily the 'wrong' way?