Ok, so it's only 6:30PM, and the finale isn't until 10PM, but I feel like commenting anyway. So who's it going to be? Stephanie? Richard? Lisa?
Lisa: I honestly don't even know why she's still on the show. She's not an especially awesome chef, she's not an especially awesome person, and she seems to survive by being just a bit not as bad as each week's loser. There's a lot of conspiracy theories that Lisa's there simply to have a "bad guy" that the viewers can root against, and I've gotta admit, it's working, since I'm rooting against her.
So it's down to Stephanie or Richard. In my opinion, Richard can visualize a "great" dish better than anyone else, and he's got all sorts of tricks up his sleeve that he can whip out at a moment's notice. Stephanie, by contrast, isn't quite as creative, but in terms of pure cooking skill I think she's superior to Richard. Her meals are always solid, but she doesn't push the envelope or go out on a limb. Of course, the flip side to that is that she's safer and less likely to make a mistake.
What is all means is that Richard controls tonight's contest. Stephanie will perform exceptionally. Richard will either be flawless and perform extra-exceptionally, or he'll make a mistake and perform less than exceptionally. If I had to choose, my money's on Richard; the probability that he makes a mistake is small (he is, after all, a top finalist), and as long as he doesn't make a mistake, his dish will be the better.