This month's issue of Big Gangan had 8 additional pages to Shinohayu chapter 50, in addition to chapter 51 of course. They are all in the same file below. The extra pages go first, the story continues right were the last chapter left off, with Hayari's last hand. Then chapter 51 begins with the color pages. For the files of the extra pages, I continued the numbering of the previous chapter to distinguish them from chapter 51 proper. I hope it's all clear.
It's Chihi time!
Shinohayu ch50extra+ch51 (Mediafire)
By the way, since Chihiro seems to be wearing the Senriyama uniform on the cover of Shinohayu volume 8, I guess that means she'll be a long-term rival for Shino, all the way to the InterHigh even. Nice. I'm looking forward to a confrontation between the two.
To further explain the winning conditions in this tournament: if none of the schools have 3 wins by the end of the captain match, the school with the highest overall score wins the tournament, regardless of how many wins they have obtained. At the end of the vice-captain match, Komosawa has 187400 points and Yumachi has 175000 points, so that's why the 12400 points difference mentioned in this chapter is important. The other two schools are far behind (Himebara 62500 points, Hirefuri 55100 points).