DaVinci is a monthly books and manga magazine, While it does have some cache, it also has an associated DDNavi site that has a "underwear shot" tag for its anime coverage. With the fall season underway they put some of their best otaku to work, going frame by frame, employing a strict set of criteria to determine which of the new series has the most shirt flashes. Basically it boils down the the skirt getting raised such that there's visible underwear
And the winners, based two episode, 41 subjects checked, are...
1：Yozakura Quartet (17 Panty Shots)
2：Freezing Vibration (8 PS)
3：I Couldn’t Become a Hero, So I Reluctantly Decided to Get a Job. (7 PS)
4：Walkure Romance (4 PS)
5：My Mental Choices Are Completely Interfering With My School Romantic Comedy、Strike the Blood、Kill la Kill (2 PS)
8：Tokyo Ravens、Machine Doll (1 PS)
10： Infinite Stratos 2 (0.5 PS)
Some anime where panty flashes were notably expected, but absent included...
And low level shot promo art, and swooshing in the opening but no flashes... Teekyu 3
From your winning anime...