I tend to nudge "up", as I feel like this gives you some extra bounce off of rubbers as the ball is hitting it. This is especially effective on a game like STTNG that's notorious for its right outlane. Normally the ball gets sucked right down, but with a nudge up as it is about to hit the right along, it'll go high enough to ricochet off of the yellow stand up targets and back into play almost every time.