You are serious?
You really don't get why its almost a sure thing that Shiraitodai is going to the finals?
As for Shiraitodai going to the finals which argument do you want? Story-telling perspective? Strength? Or current flow of the last match?
Let's see. Storytelling perspective.
Shiraitodai is undoubtedly the last boss of the tournament. They are the favorite to win. Heck, they won it for the last two years. I don't know about you, but I can't see Achiga, Senriyama or Shindouji replacing their spot. Even if they fell short of their hype, Shiraitodai as a whole is still the strongest team in Side-A.
There is also in term of potentiality. Senriyama, Shindouji and yes even Achiga barring any strategy that Akado can come up with has already shown all their cards. This still hasn't happened with Shiraitodai. Teru, Sumire and Takami can still get scarier.
Beside that, Saki entire motivation is talking to Teru through mahjong. And I'm beginning to believe that this 'talking' can be done indirectly. Consider this, Saki and Teru refuse to watch each other match. The only match that they will be forced to actually watch each other is when their team face each other. Perhaps there is something they want the other sibling to see/understand about their current playstyle?
As for the current match. I, myself, has been burned by the Awai hype. But, really. Awai is doing good all things considered. Just look at the point difference. She's raking a lot of points. The only plausible scenario for Shiraitodai to lose this current battle is if Awai was hitted directly by the incoming dealer yakuman. And even then, some calculations show that they will be able to retain second or even first simply to the high value hands that Awai was making.